Product Order Technical Tools & Support & Folder Now Documents Software Community

OPA1656 SBOS901A –MARCH 2019–REVISED JULY 2019 OPA1656 Ultra-Low-Noise, Low-Distortion, FET-Input, Burr-BrownTM Audio Operational Amplifier

1 Features 3 Description The OPA1656 is a Burr-Brown™ operational amplifier 1• Ultra-low noise: (op amp) designed specifically for audio and industrial – Voltage noise: 2.9 nV/√Hz at 10 kHz applications, where maintaining signal fidelity is – Current noise: 6 fA/√Hz at 1 kHz crucial. The FET-input architecture achieves a low • Low distortion: 2.9-nV/√Hz voltage noise density and 6-fA/√Hz current noise density, allowing for very low noise – 0.000029% (–131 dB) at 1 kHz performance in a wide variety of circuits. The high – 0.000035% (–129 dB) at 20 kHz bandwidth and high open-loop-gain design of the • High open-loop gain: 150 dB OPA1656 delivers a low distortion of 0.000035% • High output current: 100 mA (–129 dB) at 20 kHz, and improves audio signal fidelity across the full audio bandwidth. This device • Low input bias current: 10 pA also features excellent output current drive capability, • Slew rate: 24 V/μs offering rail-to-rail output swing to within 250 mV of • Gain bandwidth product: 53 MHz the power supplies with a 2-kΩ load, and can deliver 100 mA of output current. • Rail-to-rail output • Wide supply range: The OPA1656 operates over a very wide supply ±2.25 V to ±18 V or 4.5 V to 36 V range of ±2.25 V to ±18 V or (4.5 V to 36 V) on 3.9 mA of supply current to accommodate the power • Quiescent current: 3.9 mA per channel supply constraints of many types of audio products. The temperature range is specified from –40°C to 2 Applications +125°C. The device is offered in an 8-pin SOIC • Soundbar package. • Turntable Device Information(1) • DJ controllers, mixers, and other DJ equipment PART NUMBER PACKAGE BODY SIZE (NOM) • Professional audio mixer or control surface OPA1656 SOIC (8) 4.90 mm × 3.91 mm • High-fidelity D/A converter (1) For all available packages, see the package option addendum • Guitar effects pedal at the end of the data sheet. • Guitar amplifier and other music instrument amplifier Ultra-Low Input Voltage Noise • Professional microphones and systems • and headphones 100 • Vibration analysis Hz) µ Active Baxandall Tone Control

Pad 10 Bass

œ +15

Input + 1/2 œ Output Voltage Noise Density (nV/ OPA1656 + 1/2 OPA1656 1 -15 10 100 1k 10k 100k 1M 10M Treble Frequency (Hz) C020

1

An IMPORTANT NOTICE at the end of this data sheet addresses availability, warranty, changes, use in safety-critical applications, intellectual property matters and other important disclaimers. PRODUCTION DATA. OPA1656 SBOS901A –MARCH 2019–REVISED JULY 2019 www.ti.com

Table of Contents

1 Features ...... 1 8 Application and Implementation ...... 18 2 Applications ...... 1 8.1 Application Information...... 18 3 Description ...... 1 8.2 Typical Applications ...... 19 4 Revision History...... 2 9 Power Supply Recommendations...... 25 5 Pin Configuration and Functions ...... 3 10 Layout...... 25 6 Specifications...... 4 10.1 Layout Guidelines ...... 25 6.1 Absolute Maximum Ratings ...... 4 10.2 Layout Example ...... 26 6.2 ESD Ratings...... 4 11 Device and Documentation Support ...... 27 6.3 Recommended Operating Conditions...... 4 11.1 Device Support...... 27 6.4 Thermal Information...... 4 11.2 Documentation Support ...... 28 6.5 Electrical Characteristics...... 5 11.3 Receiving Notification of Documentation Updates 28 6.6 Typical Characteristics...... 7 11.4 Community Resource...... 28 7 Detailed Description ...... 14 11.5 Trademarks ...... 28 7.1 Overview ...... 14 11.6 Electrostatic Discharge Caution...... 28 7.2 Functional Block Diagram ...... 14 11.7 Glossary ...... 28 7.3 Feature Description...... 14 12 Mechanical, Packaging, and Orderable 7.4 Device Functional Modes...... 17 Information ...... 28

4 Revision History

Changes from Original (March 2019) to Revision A Page

• Changed device status from advanced information (preview) to production data (active) ...... 1

2 Submit Documentation Feedback Copyright © 2019, Texas Instruments Incorporated Product Folder Links: OPA1656 OPA1656 www.ti.com SBOS901A –MARCH 2019–REVISED JULY 2019

5 Pin Configuration and Functions

D Package 8-Pin SOIC Top View

OUT A 1 8 V+

œIN A 2 7 OUT B

+IN A 3 6 œIN B

Vœ 4 5 +IN B

Not to scale

Pin Functions PIN I/O DESCRIPTION NAME NO. –IN A 2 I Inverting input, channel A +IN A 3 I Noninverting input, channel A –IN B 6 I Inverting input, channel B +IN B 5 I Noninverting input, channel B OUT A 1 O Output, channel A OUT B 7 O Output, channel B V– 4 — Negative (lowest) power supply V+ 8 — Positive (highest) power supply

Copyright © 2019, Texas Instruments Incorporated Submit Documentation Feedback 3 Product Folder Links: OPA1656 OPA1656 SBOS901A –MARCH 2019–REVISED JULY 2019 www.ti.com

6 Specifications

6.1 Absolute Maximum Ratings over operating free-air temperature range (unless otherwise noted)(1) MIN MAX UNIT

Supply voltage, VS = (V+) – (V–) 40 V Voltage Input (V–) – 0.5 (V+) + 0.5 V Input (all pins except power-supply pins) –10 10 mA Current Output short-circuit(2) Continuous

Operating, TA –55 125 °C

Temperature Junction, TJ 150 °C

Storage, Tstg –65 150 °C (1) Stresses beyond those listed under Absolute Maximum Ratings may cause permanent damage to the device.Theseare stress ratings only, which do not imply functional operation of the device at these oranyother conditions beyond those indicated under RecommendedOperatingConditions. Exposure to absolute-maximum-rated conditions for extended periodsmayaffect device reliability. (2) Short-circuit to VS / 2 (groundinsymmetrical dual-supply setups), one amplifier per package.

6.2 ESD Ratings VALUE UNIT Human-body model (HBM), per ANSI/ESDA/JEDEC JS-001(1) ±2000 V(ESD) Electrostatic discharge V Charged-device model (CDM), per JEDEC specification JESD22-C101(2) ±1000

(1) JEDEC document JEP155 states that 500-V HBM allowssafemanufacturing with a standard ESD control process. (2) JEDEC document JEP157 states that 250-V CDM allowssafemanufacturing with a standard ESD control process.

6.3 Recommended Operating Conditions over operating free-air temperature range (unless otherwise noted) MIN NOM MAX UNIT Supply voltage 4.5 (±2.25) 36 (±18) V

Operating temperature, TA –40 125 °C

6.4 Thermal Information OPA1656 THERMAL METRIC(1) D (SOIC) UNIT 8 PINS

RθJA Junction-to-ambient thermal resistance 119.9 °C/W

RθJC(top) Junction-to-case (top) thermal resistance 51.8 °C/W

RθJB Junction-to-board thermal resistance 65.4 °C/W

ψJT Junction-to-top characterization parameter 10.0 °C/W

ψJB Junction-to-board characterization parameter 64.2 °C/W

RθJC(bot) Junction-to-case (bottom) thermal resistance – °C/W (1) For more information about traditional and new thermal metrics, see the Semiconductor and IC Package Thermal Metrics application report.

4 Submit Documentation Feedback Copyright © 2019, Texas Instruments Incorporated Product Folder Links: OPA1656 OPA1656 www.ti.com SBOS901A –MARCH 2019–REVISED JULY 2019

6.5 Electrical Characteristics at TA = 25°C, VS = ±18 V, RL = 2 kΩ, and VCM = VOUT = VS/2 (unless otherwise noted) PARAMETER TEST CONDITIONS MIN TYP MAX UNIT AUDIO PERFORMANCE

G = 1, RL = 600 Ω, VO = 3.5 VRMS, f = 1 kHz, 0.000029% 80-kHz measurement bandwidth –131 dB

G = 1, RL = 600 Ω, VO = 3.5 VRMS, f = 20 kHz, 0.0001% 80-kHz measurement bandwidth –120 dB THD+N Total harmonic distortion + noise G = 1, RL = 2 kΩ, VO = 3.5 VRMS, f = 1 kHz, 0.000029% 80-kHz measurement bandwidth –131 dB

G = 1, RL = 2 kΩ, VO = 3.5 VRMS, f = 20 kHz, 0.000035% 80-kHz measurement bandwidth –129 dB SMPTE/DIN two-tone, 4:1 0.000018% G = 1 (60 Hz and 7 kHz) –135 dB IMD Intermodulation distortion VO = 3.5 VRMS CCIF twin-tone 0.000020% (19 kHz and 20 kHz) –134 dB FREQUENCY RESPONSE Gain-bandwidth product G = 100 53 MHz GBW Unity gain bandwidth G = 1 20 MHz SR Slew rate G = –1, 10-V step 24 V/µs (1) Full power bandwidth VO = 1 VP 3.8 MHz Overload recovery time G = –10 100 ns Channel separation f = 1 kHz –135 dB Settling time 0.01%, G = –1, 10-V step 800 ns NOISE

f = 20 Hz to 20 kHz 0.53 µVRMS Input voltage noise f = 0.1 Hz to 10 Hz 1.9 µVPP f = 100 Hz 11.8 nV/√Hz

en Input voltage noise density f = 1 kHz 4.3 nV/√Hz f = 10 kHz 2.9

in Input current noise density f = 1 kHz 6 fA/√Hz OFFSET VOLTAGE

VOS Input offset voltage VS = ±2.25 V to ±18 V ±0.5 ±1 mV

VS = ±2.25 V to ±18 V dVOS/dT Input offset voltage drift (2) 0.3 2 µV/°C TA = –40°C to +125°C

PSRR Power-supply rejection ratio VS = ±2.25 V to ±18 V 0.3 5 µV/V INPUT BIAS CURRENT (3) IB Input bias current VCM = 0 V ±10 ±20 pA

IOS Input offset current VCM = 0 V ±10 ±20 pA INPUT VOLTAGE RANGE

VCM Common-mode voltage range (V–) (V+) – 2.25 V

CMRR Common-mode rejection ratio (V–) ≤ VCM ≤ (V+) – 2.25 106 120 dB INPUT IMPEDANCE Differential 100 || 9.1 MΩ || pF Common-mode 6 || 1.9 1012Ω || pF OPEN-LOOP GAIN (V–) + 1.3 V ≤ V ≤ (V+) – 1.3 V O 134 150 dB RL = 600 Ω AOL Open-loop voltage gain (V–) + 0.5 V ≤ V ≤ (V+) – 0.5 V O 134 154 dB RL = 2 kΩ

(1) Full-power bandwidth = SR / (2π ×VP),where SR = slew rate. (2) Specified by design and characterization. (3) Input bias current test conditions can vary from nominal ambient conditions as a result of junction temperature differences.

Copyright © 2019, Texas Instruments Incorporated Submit Documentation Feedback 5 Product Folder Links: OPA1656 OPA1656 SBOS901A –MARCH 2019–REVISED JULY 2019 www.ti.com

Electrical Characteristics (continued) at TA = 25°C, VS = ±18 V, RL = 2 kΩ, and VCM = VOUT = VS/2 (unless otherwise noted) PARAMETER TEST CONDITIONS MIN TYP MAX UNIT OUTPUT

VO Voltage output RL = 2 kΩ (V–) + 0.25 (V+) – 0.25 V

ZO Open-loop output impedance f = 1 MHz 26 Ω (4) ISC Short-circuit current ±100 mA

CL Capacitive load drive 100 pF POWER SUPPLY

IO = 0 A, VS = ±2.25 V to ±18 V 3.9 4.6 mA I Quiescent current (per channel) Q (2) IO = 0 A, TA = –40°C to +125°C 5.0 mA (4) One channel at a time.

6 Submit Documentation Feedback Copyright © 2019, Texas Instruments Incorporated Product Folder Links: OPA1656 OPA1656 www.ti.com SBOS901A –MARCH 2019–REVISED JULY 2019

6.6 Typical Characteristics at TA = 25°C, VS = ±15 V, RL = 2 kΩ, and VCM = VS/2 (unless otherwise noted)

100 Hz) µ

10 Voltage Noise Density (nV/

1 Noise (500 nV/div) Voltage Referred Input 10 100 1k 10k 100k 1M 10M Time (1 s/div) Frequency (Hz) C020 D029

Figure 1. Input Voltage Noise Density vs Frequency Figure 2. 0.1-Hz to 10-Hz Noise 1000 50 500 Voltage Noise Contribution Vs=ê18 V Resistor Noise Contribution Vs=ê15 V 200 Current Noise Contribution 40 Vs=ê2.25 V 100 Total Noise Contribution ) 50 P

Hz) 30 µ 20 10 5 20

Noise (nV/ Noise 2 1 (V Voltage Output 0.5 10 0.2 0.1 0 10 100 1k 10k 100k 1M 100 1k 10k 100k 1M 10M Source Resistance (W) Frequency (Hz) D120 D113

Figure 3. Voltage Noise vs Source Resistance Figure 4. Maximum Output Voltage vs Frequency 180 180 60 Gain G = +1 150 Phase 150 G= -1 G= +10 40 G= +100 120 120 Phase ( 90 90 20 è

60 60 ) Gain (dB) Gain (dB) Gain

30 30 0

0 0

-30 -30 -20 100m 1 10 100 1k 10k 100k 1M 10M 100 1k 10k 100k 1M 10M Frequency (Hz) Frequency (Hz) D104 D106 CL = 10 pF CL = 10 pF

Figure 5. Open-Loop Gain and Phase vs Frequency Figure 6. Closed-Loop Gain vs Frequency

Copyright © 2019, Texas Instruments Incorporated Submit Documentation Feedback 7 Product Folder Links: OPA1656 OPA1656 SBOS901A –MARCH 2019–REVISED JULY 2019 www.ti.com

Typical Characteristics (continued) at TA = 25°C, VS = ±15 V, RL = 2 kΩ, and VCM = VS/2 (unless otherwise noted) 0.01 -80 1 -40 G = -1, 600-W Load G = -1, 600-W Load G = -1, 2k-W Load G = -1, 2k-W Load G = 1, 10k Load G = -1, 10k-W Load 0.1 - -W -60 G = +1, 600-W Load G = +1, 600-W Load Noise (%) Noise (dB) Noise (%) + G = +1, 2k-W Load G = +1, 2k-W Load + + 0.001 G = +1, 10k-W Load -100 G = +1, 10k-W Load 0.01 -80

0.001 -100 0.0001 -120

0.0001 -120 Total Harmonic Total Harmonic Distortion Total Harmonic Total Harmonic Distortion Total Harmonic Total Harmonic Distortion Total Harmonic Total Harmonic Distortion + Noise (dB) 0.00001 -140 1E-5 -140 20 100 1k 10k 20k 100m 1 10 Frequency (Hz) Output Amplitude (V ) D109 RMS D110

VOUT = 3 VRMS Bandwidth = 80 kHz f = 1 kHz Bandwidth = 80 kHz

Figure 7. THD+N Ratio vs Frequency Figure 8. THD+N Ratio vs Output Amplitude 0.001 -100 0.005 0.0005 G = -1, HD2 G = -1, VIN = 1 VPP (0.354 VRMS) - 0.003 0.0002 G = 1, HD3 G = -1, VIN = 5 VPP (1.768 VRMS) - 0.002 0.0001 G = 1, HD4 -120 G = +1, VIN = 1 VPP (0.354 VRMS) - 5E-5 G = 1, HD5 G = +1, VIN = 5 VPP (1.768 VRMS) G = +1, HD2 Noise (%) 0.001 -100 + ) 2E-5 G = +1, HD3 0.0007 % 1E-5 G = +1, HD4 -140 0.0005 5E-6 G = +1, HD5 0.0003 2E-6 1E-6 -160 0.0002 Amplitude (dB) Amplitude ( 5E-7 0.0001 -120 2E-7 7E-5 1E-7 -180 5E-5 5E-8 Total Harmonic Total Harmonic Distortion 2E-8 3E-5 Total Harmonic Distortion + Noise (dB) 1E-8 -200 2E-5 20 100 1k 10k 20k ê5 ê10 ê18 Frequency (Hz) V (V) D111 S D141

VOUT = 3 VRMS Bandwidth = 80 kHz f = 1 kHz RL = 2 kΩ Bandwidth = 80 kHz

Figure 9. Individual Harmonic Amplitude vs Frequency Figure 10. THD+N vs Supply Voltage 0.1 -60 0 CCIF SMPTE -20 -40 0.01 -80 -60 -80 0.001 -100 -100 -120

Amplitude (dBc) -140 0.0001 -120 -160 Intermodulation Distortion (dB)Intermodulation Intermodulation Distortion (%)Intermodulation -180 1E-5 -140 -200 10m 100m 1 10 20 100 1k 10k 50k Output Amplitude (V ) Frequency (Hz) RMS D140 D142

Bandwidth = 80 kHz G = 1, VOUT = 3 VRMS RL = 2 kΩ Bandwidth = 80 kHz

Figure 11. Intermodulation Distortion vs Amplitude Figure 12. FFT, 1-kHz Sine Wave

8 Submit Documentation Feedback Copyright © 2019, Texas Instruments Incorporated Product Folder Links: OPA1656 OPA1656 www.ti.com SBOS901A –MARCH 2019–REVISED JULY 2019

Typical Characteristics (continued) at TA = 25°C, VS = ±15 V, RL = 2 kΩ, and VCM = VS/2 (unless otherwise noted) 0 0 -20 -20 -40 -40 -60 -60 -80 -80 -100 -100 -120 -120

Amplitude (dBc) -140 Amplitude (dBc) -140 -160 -160 -180 -180 -200 -200 1k 10k 80k 0 20k 40k 60k 80k Frequency (Hz) Frequency (Hz) D143 D143 G = 1, VOUT = 3 VRMS RL = 2 kΩ Bandwidth = 80 kHz VOUT = 3 VRMS RL = 2 kΩ Bandwidth = 80 kHz

Figure 13. FFT, 10-kHz Sine Wave Figure 14. FFT, CCIF Input (19 kHz + 20 kHz) -60 160 PSRR+ 140 PSRR- -80 CMRR 120 -100 100

-120 80

60 -140 RejectionRatio (dB) 40 Channel Seperation (dB)Channel -160 20

-180 0 1k 10k 100k 1M 10M 1 10 100 1k 10k 100k 1M 10M Frequency (Hz) Frequency (Hz) D114 D107 VOUT = 3 VRMS G = 1

Figure 15. Channel Separation vs Frequency Figure 16. CMRR and PSRR vs Frequency (Referred to Input) 147 126

146 125

145 124

144 123 Power Supply Rejection Ratio (dB) Common-Mode Rejection Ratio (dB)

143 122 -40 -25 -10 5 20 35 50 65 80 95 110 125 -40 -25 -10 5 20 35 50 65 80 95 110 125 Temperature ( C) Temperature ( C) è D028 è D027

Figure 17. Power Supply Rejection Ratio vs Temperature Figure 18. Common Mode Rejection Ratio vs Temperature (Referred to Input) (Referred to Input)

Copyright © 2019, Texas Instruments Incorporated Submit Documentation Feedback 9 Product Folder Links: OPA1656 OPA1656 SBOS901A –MARCH 2019–REVISED JULY 2019 www.ti.com

Typical Characteristics (continued) at TA = 25°C, VS = ±15 V, RL = 2 kΩ, and VCM = VS/2 (unless otherwise noted) 15 30

25

10 20

15

5 10 Total Amplifiers (%) Total Amplifiers (%)

5

-1000 -750 -500 -250 0 250 500 750 1000 -2 -1.5 -1 -0.5 0 0.5 1 1.5 2 Input Offset Voltage ( V) Offset Voltage Drift ( V/ C) m D001 m è D004 Count = 7955 Count = 32

Figure 19. Input Offset Voltage Distribution Figure 20. Input Offset Voltage Drift Distribution 1 100 -40èC 75

0.5 50 V) m 25

0 0

-25 Offset Voltage ( Offset Voltage Offset Voltage (mV) Offset Voltage -0.5 -50 25èC 125èC 85èC -75

-1 -100 -40 -25 -10 5 20 35 50 65 80 95 110 125 -18 -15 -12 -9 -6 -3 0 3 6 9 12 15 18 Temperature ( C) Input Common-Mode Voltage (V) è D017 D019 5 typical units shown

Figure 21. Input Offset vs Temperature Figure 22. Input Offset vs Common Mode Voltage

VIN VIN VOUT VOUT Voltage (5 mV/div) Voltage (5 mV/div) Voltage

Time (1 ms/div) Time (1 ms/div) D137 D135 G = 1 CL = 20 pF G = –1 CL = 100 pF

Figure 23. Small-Signal Step Response (100 mV) Figure 24. Small-Signal Step Response (100 mV)

10 Submit Documentation Feedback Copyright © 2019, Texas Instruments Incorporated Product Folder Links: OPA1656 OPA1656 www.ti.com SBOS901A –MARCH 2019–REVISED JULY 2019

Typical Characteristics (continued) at TA = 25°C, VS = ±15 V, RL = 2 kΩ, and VCM = VS/2 (unless otherwise noted)

VIN VIN VOUT VOUT Voltage (5 V/div)Voltage Voltage (5 V/div)Voltage

Time (1 ms/div) Time (1 ms/div) D136 D139 G = 1 RL = 2 kΩ CL = 100 pF G = –1 CL = 100 pF

Figure 25. Large-Signal Step Response Figure 26. Large-Signal Step Response 158 100 50 IB+ 156 20 IB- 10 IOS 5 154 2 1 152 0.5 (dB)

OL 0.2

A 150 0.1 0.05 148

Input Bias CurrentInput (nA) 0.02 0.01 146 0.005 0.002 144 0.001 -40 -25 -10 5 20 35 50 65 80 95 110 125 -40 -25 -10 5 20 35 50 65 80 95 110 125 Temperature( C) Temperature ( C) è D033 è D024

Figure 27. Open-Loop Gain vs Temperature Figure 28. IB and IOS vs Temperature 30 4 IB- VS = 4.5 V IB+ VS = 36 V 20 IOS 3.9 10

0 3.8

-10 Input Bias Current (pA) Input

Quiescent Current(mA) 3.7 -20

-30 3.6 -18 -15 -12 -9 -6 -3 0 3 6 9 12 15 18 -40 -25 -10 5 20 35 50 65 80 95 110 125 Input Common-Mode Voltage (V) Temperature ( C) D023 è D031

Figure 29. IB and IOS vs Common-Mode Voltage Figure 30. Supply Current vs Temperature

Copyright © 2019, Texas Instruments Incorporated Submit Documentation Feedback 11 Product Folder Links: OPA1656 OPA1656 SBOS901A –MARCH 2019–REVISED JULY 2019 www.ti.com

Typical Characteristics (continued) at TA = 25°C, VS = ±15 V, RL = 2 kΩ, and VCM = VS/2 (unless otherwise noted) 4.5 18

4 17 25èC -40èC 3.5 16

3 15

125èC 2.5 14 Output Voltage (V) Voltage Output Quiescent Current(mA) 2 13 85èC

1.5 12 0 4 8 12 16 20 24 28 32 36 0 10 20 30 40 50 60 70 80 90 100 110 120 Supply Voltage (V) Output Current (mA) D030 D025

Figure 31. Supply Current vs Supply Voltage Figure 32. Output Voltage vs Output Current (Sourcing) -12 140 Sinking 85èC 132 Sourcing -13 124 116 -14 125èC 108 -15 100 92 -16

Output Voltage (V) Voltage Output 84

25èC Short Circuit Current (mA) 76 -17 -40èC 68 -18 60 0 10 20 30 40 50 60 70 80 90 100 110 120 -40 -25 -10 5 20 35 50 65 80 95 110 125 Output Current (mA) Temperature ( C) D026 è D041

Figure 33. Output Voltage vs Output Current (Sinking) Figure 34. Short-Circuit Current vs Temperature 75 100 RISO = 0 W 90 RISO = 25 W RISO = 50 W 80 50 ) è ) 70 % 60 25 50 Overshoot (

Phase Margin ( Phase Margin 40 0 30

20

-25 10 10 100 500 10 100 1000 Load Capacitance, C (pF) Load Capacitance, C (pF) L D105 L D037 G = 1 G = 1

Figure 35. Phase Margin vs Capacitive Load Figure 36. Percent Overshoot vs Capacitive Load

12 Submit Documentation Feedback Copyright © 2019, Texas Instruments Incorporated Product Folder Links: OPA1656 OPA1656 www.ti.com SBOS901A –MARCH 2019–REVISED JULY 2019

Typical Characteristics (continued) at TA = 25°C, VS = ±15 V, RL = 2 kΩ, and VCM = VS/2 (unless otherwise noted) 60 RISO = 0 W RISO = 25 W 50 RISO = 50 W

) 40 %

30 Overshoot ( Overshoot

20 (5 V/div)Voltage

10 VIN VOUT 0 10 100 1000 Time (400 ns/div) Load Capacitance, C (pF) L D131 D134 G = –1 G = –10

Figure 37. Percent Overshoot vs Capacitive Load Figure 38. Negative Overload Recovery 1000

100

(W) 10 O Z

1

0.1 1 10 100 1k 10k 100k 1M 10M Frequency (Hz) D112 G = –10

Figure 39. Positive Overload Recovery Figure 40. Open-Loop Output Impedance vs Frequency

VIN VOUT Voltage (5 V/div)Voltage

Time (400 ns/div)

D138 G = 1

Figure 41. No Phase Reversal

Copyright © 2019, Texas Instruments Incorporated Submit Documentation Feedback 13 Product Folder Links: OPA1656 OPA1656 SBOS901A –MARCH 2019–REVISED JULY 2019 www.ti.com

7 Detailed Description

7.1 Overview The OPA1656 uses a three-gain-stage architecture to achieve very low noise and distortion. The Functional Block Diagram shows a simplified schematic of the OPA1656 (one channel shown). The device consists of a low noise input stage and feedforward pathway coupled to a high-current output stage. This topology exhibits superior distortion performance under a wide range of loading conditions compared to other operational amplifiers.

7.2 Functional Block Diagram

Feed- forward Path

CM1

CM2 +IN Input Gain Output OUT Stage Stage Stage -IN

7.3 Feature Description

7.3.1 Phase Reversal Protection The OPA1656 has internal phase-reversal protection. Many op amps exhibit phase reversal when the input is driven beyond the linear common-mode range. This condition is most often encountered in noninverting circuits when the input is driven beyond the specified common-mode voltage range, causing the output to reverse into the opposite rail. The input of the OPA1656 prevents phase reversal with excessive common-mode voltage. Instead, the appropriate rail limits the output voltage. This performance is shown in Figure 42.

20

15

10

5

0

Voltage Voltage (V) -5

-10

-15 VIN VOUT -20 Time (125 s/div)

C004 Figure 42. Output Waveform Devoid of Phase Reversal During an Input Overdrive Condition

7.3.2 Electrical Overstress Designers often ask questions about the capability of an operational amplifier to withstand electrical overstress. These questions tend to focus on the device inputs, but can involve the supply voltage pins or even the output pin. Each of these different pin functions have electrical stress limits determined by the voltage breakdown characteristics of the particular semiconductor fabrication process and specific circuits connected to the pin. Additionally, internal electrostatic discharge (ESD) protection is built into these circuits to protect them from accidental ESD events both before and during product assembly.

14 Submit Documentation Feedback Copyright © 2019, Texas Instruments Incorporated Product Folder Links: OPA1656 OPA1656 www.ti.com SBOS901A –MARCH 2019–REVISED JULY 2019

Feature Description (continued) A good understanding of this basic ESD circuitry and the relevance to an electrical overstress event is helpful. Figure 43 illustrates the ESD circuits contained in the OPA1656 (indicated by the dashed line area). The ESD protection circuitry involves several current-steering diodes connected from the input and output pins and routed back to the internal power-supply lines, where the diodes meet at an absorption device internal to the operational amplifier. This protection circuitry is intended to remain inactive during normal circuit operation.

TVS

RF œ +

+VS

R1 INœ 20 Ω

RS IN+ 20 Ω + Power-Supply ESD Cell RL +

VIN œ + œ

œVS

TVS

Figure 43. Equivalent Internal ESD Circuitry Relative to a Typical Circuit Application

An ESD event produces a short-duration, high-voltage pulse that is transformed into a short-duration, high- current pulse when discharging through a semiconductor device. The ESD protection circuits are designed to provide a current path around the operational amplifier core to prevent damage. The energy absorbed by the protection circuitry is then dissipated as heat. When an ESD voltage develops across two or more amplifier device pins, current flows through one or more steering diodes. Depending on the path that the current takes, the absorption device can activate. The absorption device has a trigger, or threshold voltage, that is above the normal operating voltage of the OPA1656 but below the device breakdown voltage level. When this threshold is exceeded, the absorption device quickly activates and clamps the voltage across the supply rails to a safe level. When the operational amplifier connects into a circuit, as shown in Figure 43, the ESD protection components are intended to remain inactive and do not become involved in the application circuit operation. However, circumstances may arise where an applied voltage exceeds the operating voltage range of a given pin. If this condition occurs, there is a risk that some internal ESD protection circuits can turn on and conduct current. Any such current flow occurs through steering-diode paths and rarely involves the absorption device.

Figure 43 shows a specific example where the input voltage (VIN) exceeds the positive supply voltage (V+) by 500 mV or more. Much of what happens in the circuit depends on the supply characteristics. If V+ can sink the current, one of the upper input steering diodes conducts and directs current to V+. Excessively high current levels can flow with increasingly higher VIN. As a result, the data sheet specifications recommend that applications limit the input current to 10 mA.

Copyright © 2019, Texas Instruments Incorporated Submit Documentation Feedback 15 Product Folder Links: OPA1656 OPA1656 SBOS901A –MARCH 2019–REVISED JULY 2019 www.ti.com

Feature Description (continued)

If the supply is not capable of sinking the current, VIN can begin sourcing current to the operational amplifier and then take over as the source of positive supply voltage. The danger in this case is that the voltage can rise to levels that exceed the operational amplifier absolute maximum ratings. Another common question involves what happens to the amplifier if an input signal is applied to the input when the power supplies (V+ or V–) are at 0 V. Again, this question depends on the supply characteristic when at 0 V, or at a level below the input signal amplitude. If the supplies appear as high impedance, then the input source supplies the operational amplifier current through the current-steering diodes. This state is not a normal bias condition; most likely, the amplifier does not operate normally. If the supplies are low impedance, then the current through the steering diodes can become quite high. The current level depends on the ability of the input source to deliver current, and any resistance in the input path. If there is any uncertainty about the ability of the supply to absorb this current, add external Zener diodes to the supply pins; see Figure 43. Select the Zener voltage so that the diode does not turn on during normal operation. However, the Zener voltage must be low enough so that the Zener diode conducts if the supply pin begins to rise above the safe-operating, supply-voltage level.

7.3.3 EMI Rejection Ratio (EMIRR) The electromagnetic interference (EMI) rejection ratio, or EMIRR, describes the EMI immunity of operational amplifiers. An adverse effect that is common to many operational amplifiers is a change in the offset voltage as a result of RF signal rectification. An operational amplifier that is more efficient at rejecting this change in offset as a result of EMI has a higher EMIRR and is quantified by a decibel value. Measuring EMIRR can be performed in many ways, but this document provides the EMIRR IN+, which specifically describes the EMIRR performance when the RF signal is applied to the noninverting input pin of the operational amplifier. In general, only the noninverting input is tested for EMIRR for the following three reasons: • Operational amplifier input pins are known to be the most sensitive to EMI, and typically rectify RF signals better than the supply or output pins. • The noninverting and inverting operational amplifier inputs have symmetrical physical layouts and exhibit nearly matching EMIRR performance. • EMIRR is easier to measure on noninverting pins than on other pins because the noninverting input pin can be isolated on a printed-circuit-board (PCB). This isolation allows the RF signal to be applied directly to the noninverting input pin with no complex interactions from other components or connecting PCB traces. A more formal discussion of the EMIRR IN+ definition and test method is provided in the EMI Rejection Ratio of Operational Amplifiers application report, available for download at www.ti.com. The EMIRR IN+ of the OPA1656 is plotted versus frequency in Figure 44. If available, any dual and quad operational amplifier device versions have nearly identical EMIRR IN+ performance. The OPA1656 unity-gain bandwidth is 20 MHz. EMIRR performance below this frequency denotes interfering signals that fall within the operational amplifier bandwidth.

140

120

100

80

EMIRR IN+ (dB) 60

40

20 10M 100M 1G 10G Frequency (Hz) D115 Figure 44. OPA1656 EMIRR vs Frequency

16 Submit Documentation Feedback Copyright © 2019, Texas Instruments Incorporated Product Folder Links: OPA1656 OPA1656 www.ti.com SBOS901A –MARCH 2019–REVISED JULY 2019

Feature Description (continued) Table 1 lists the EMIRR IN+ values for the OPA1656 at particular frequencies commonly encountered in real- world applications. Applications listed in Table 1 can be centered on or operated near the particular frequency shown. This information can be of special interest to designers working with these types of applications, or working in other fields likely to encounter RF interference from broad sources, such as the industrial, scientific, and medical (ISM) band.

Table 1. OPA1656 EMIRR IN+ for Frequencies of Interest FREQUENCY APPLICATION OR ALLOCATION EMIRR IN+ 400 MHz Mobile radio, mobile satellite, space operation, weather, radar, UHF 36 dB GSM, radio communication and navigation, GPS (to 1.6 GHz), ISM, 900 MHz 42 dB aeronautical mobile, UHF 1.8 GHz GSM, mobile personal comm. broadband, satellite, L-band 52 dB 2.4 GHz 802.11b/g/n, ™, mobile personal comm., ISM, and satellite, S-band 64 dB 3.6 GHz , aero comm./nav., satellite, mobile, S-band 67 dB 802.11a/n, aero communication and navigation, mobile communication, 5 GHz 77 dB space and satellite operation, C-band

7.3.3.1 EMIRR IN+ Test Configuration Figure 45 shows the circuit configuration for testing the EMIRR IN+. An RF source is connected to the operational amplifier noninverting input pin using a transmission line. The operational amplifier is configured in a unity-gain buffer topology with the output connected to a low-pass filter (LPF) and a digital multimeter (DMM). A large impedance mismatch at the operational amplifier input causes a voltage reflection; however, this effect is characterized and accounted for when determining the EMIRR IN+. The resulting dc offset voltage is sampled and measured by the multimeter. The LPF isolates the multimeter from residual RF signals that can interfere with multimeter accuracy. See the EMI Rejection Ratio of Operational Amplifiers application report for more details.

Ambient temperature: 25˘C

+VS

œ 50 Low-Pass Filter +

RF source -VS DC Bias: 0 V Sample / Modulation: None (CW) Averaging Digital Multimeter Frequency Sweep: 201 pt. Log Not shown: 0.1 µF and 10 µF supply decoupling

Figure 45. EMIRR IN+ Test Configuration Schematic

7.4 Device Functional Modes

7.4.1 Operating Voltage The OPA1656 operates from ±2.25 V to ±18 V supplies while maintaining excellent performance. The OPA1656 can operate with as little as 4.5 V between the supplies and with up to 36 V between the supplies. However, some applications do not require equal positive and negative output voltage swing. With the OPA1656, power- supply voltages are not required to be equal. For example, the positive supply can be set to 25 V with the negative supply at –5 V. In all cases, the common-mode voltage must be maintained within the specified range. In addition, key parameters are specified over the temperature range of TA = –40°C to 125°C.

Copyright © 2019, Texas Instruments Incorporated Submit Documentation Feedback 17 Product Folder Links: OPA1656 OPA1656 SBOS901A –MARCH 2019–REVISED JULY 2019 www.ti.com

8 Application and Implementation

NOTE Information in the following applications sections is not part of the TI component specification, and TI does not warrant its accuracy or completeness. TI’s customers are responsible for determining suitability of components for their purposes. Customers should validate and test their design implementation to confirm system functionality.

8.1 Application Information

8.1.1 Basic Noise Calculations Low-noise circuit design requires careful analysis of all noise sources. External noise sources can dominate in many cases; consider the effect of source resistance on overall op amp noise performance. Total noise of the circuit is the root-sum-square combination of all noise components. Figure 46 shows noninverting (A) and inverting (B) op amp circuit configurations with gain. In circuit configurations with gain, the feedback network resistors contribute noise. In general, the current noise of the op amp reacts with the feedback resistors to create additional noise components. The selected feedback resistor values make these noise sources negligible. Low impedance feedback resistors load the output of the amplifier. The equations for total noise are shown for both configurations.

(A) Noise in Noninverting Gain Configuration Noise at the output is given as EO, where

R R 1 2 2 4 2 4 „ 4 ' 2 A 2 A 2 A E 4 2 E 1 2 8 1 1 = 1 + „ 5 + 0 + 41æ42 + 0 „ 5 + 0 „ 4/5 : ; l 41p ¨: ; : ; k o : ; l d41 + 42hp > ? GND œ EO 8 + 2 A5 = 4 „ G$ „ 6(-) „ 45 Thermal noise of RS : ; ¥ d ¾*V h

RS 4 „ 4 8 A G 6 - 1 2 3 41æ42 = 4 „ $ „ ( ) „ Thermal noise of R1 || R2 : ; ¨ d41 + 42h d ¾*V h + VS , œ 4 G = 1.38065 „ 10 23 $ F Boltzmann Constant : ; d - h Source 5 6(-) = 237.15+ 6(°%) - Temperature in kelvins GND : ; > ?

(B) Noise in Inverting Gain Configuration Noise at the output is given as EO, where

R R 1 2 2 4 2 4 + 4 „ 4 ' 2 A 2 A E 5 1 2 8 6 1 = 1 + „ 0 + 41+45 æ42 + 0 „ : ; 4/5 : ; l 45 + 41p ¨: ; k o F H 45 + 41 + 42 IG > ? RS œ EO + 45 + 41 „ 42 8 7 A4 +4 æ4 = 4 „ G$ „ 6(-) „ : ; : ; 1 5 2 H 4 + 4 + 4 I ¾*V Thermal noise of (R1 + RS) || R2 + ¨ 5 1 2 d h VS œ GND , 8 G = 1.38065 „ 10 23 Boltzmann Constant Source $ F : ; d - h GND 9 6(-) = 237.15+ 6(°%) - Temperature in kelvins : ; > ?

Copyright © 2017, Texas Instruments Incorporated

(1) eN is the voltage noise of the amplifier. For the OPA1656, eN = 4.3 nV/√Hz at 1 kHz.

(2) iN is the current noise of the amplifier. For the OPA1656, iN = 6 fA/√Hz at 1 kHz. (3) For additional resources on noise calculations, see TI's Precision Labs Series. Figure 46. Noise Calculation in Gain Configurations

18 Submit Documentation Feedback Copyright © 2019, Texas Instruments Incorporated Product Folder Links: OPA1656 OPA1656 www.ti.com SBOS901A –MARCH 2019–REVISED JULY 2019

8.2 Typical Applications

8.2.1 Preamplifier Circuit for Vinyl Record Playback With Moving-Magnet Phono Cartridges The noise and distortion performance of the OPA1656 is exceptional in applications with high source impedances, which makes these devices an excellent choice in preamplifier circuits for moving magnet phono cartridges. The high source impedance of the cartridge, and high gain required by the RIAA playback curve at low frequency, requires an amplifier with both low input current noise and low input voltage noise.

15 V MM Phono Input C5 R5 100 uF + OPA1656 100 V+ Output R1 C1 œ VOUT 47 k 150 pF Vœ R6 100 k R2 -15 V R3 118 k 10 k

C2 C3 R4 27 nF 7.5 nF 127

C4 100 F

Copyright © 2018, Texas Instruments Incorporated Figure 47. Preamplifier Circuit for Vinyl Record Playback With Moving-Magnet Phono Cartridges (Single Channel Shown)

8.2.1.1 Design Requirements • Gain: 40 dB (1 kHz) • RIAA Accuracy: ±0.5 dB (100 Hz to 20 kHz) • Power Supplies: ±15 V

Copyright © 2019, Texas Instruments Incorporated Submit Documentation Feedback 19 Product Folder Links: OPA1656 OPA1656 SBOS901A –MARCH 2019–REVISED JULY 2019 www.ti.com

Typical Applications (continued) 8.2.1.2 Detailed Design Procedure Vinyl records are recorded using an equalization curve specified by the Recording Institute Association of America (RIAA). The purpose of this equalization curve is to decrease the amount of space occupied by a grove on the record and therefore maximize the amount of information able to be stored. Proper playback of music stored on the record requires a preamplifier circuit that applies the inverse transfer function of the recording equalization curve. The combination of the recording equalization and the playback equalization results in a flat frequency response over the audio range, as Figure 48 shows.

20

15 Playback Curve

10

5

0

Gain Gain (dB) Combined Response -5

-10

Recording Curve -15

-20 10 100 1000 10000 Frequency (Hz)

C009 Figure 48. RIAA Recording and Playback Curves Normalized at 1 kHz

The basic RIAA playback curve implements three time constants: 75 μs, 380 μs, and 3180 μs. An IEC amendment is later added to the playback curve and implements a pole in the curve at 20 Hz with the intent of protecting loudspeakers from excessive low frequency content. Rather than strictly adhering to the IEC amendment, this design moves this pole to a lower frequency to improve low frequency response and still providing protection for loudspeakers. Resistor R1 and capacitor C1 are selected to provide the proper input impedance for the moving magnet cartridge. Cartridge loading is specified by the manufacturer in the cartridge datasheet and is absolutely crucial for proper response at high frequency. 47 kΩ is a common value for the input resistor, and the capacitive loading is usually specified to 200 pF to 300 pF per channel. This capacitive loading specification includes the capacitance of the cable connecting the turntable to the preamplifier, as well as any additional parasitic capacitances at the preamplifier input. Therefore, the value of C1 must be less than the loading specification to account for these additional capacitances. The output network consisting of R5, R6, and C5 serves to ac couple the preamplifier circuit to any subsequent electronics in the signal path. The 100-Ω resistor R5 limits in-rush current into coupling capacitor C5 and prevents parasitic capacitance from cabling from causing instability. R6 prevents charge accumulation on C5. Capacitor C5 is chosen to be the same value as C4; for simplicity however, the value of C5 must be large enough to avoid attenuating low frequency information.

20 Submit Documentation Feedback Copyright © 2019, Texas Instruments Incorporated Product Folder Links: OPA1656 OPA1656 www.ti.com SBOS901A –MARCH 2019–REVISED JULY 2019

Typical Applications (continued) The feedback resistor elements must be selected to provide the correct response within the audio bandwidth. In order to achieve the correct frequency response, the passive components in Figure 47 must satisfy Equation 1, Equation 2, and Equation 3: R22ì C = 3180 m s (1)

R33ì C = 75 m s (2)

()()R2 || R 3ì C 2 + C 3 = 318 m s (3) R2, R3, and R4 must also be selected to meet the design requirements for gain. The gain at 1 kHz is determined by subtracting 20 dB from gain of the circuit at very low frequency (near dc), as shown in Equation 4:

A1kHz=- A LF 20dB (4) Therefore, the low frequency gain of the circuit must be 60 dB to meet the goal of 40 dB at 1 kHz and is determined by resistors R2, R3, and R4 as shown in Equation 5:

RR32+ ALF =+ 1 = 1000(60dB) R4 (5) Because there are multiple combinations of passive components that satisfy these equations, a spreadsheet or other software calculation tool is the easiest method to examine resistor and capacitor combinations. Capacitor C4 forces the gain of the circuit to unity at dc in order to limit the offset voltage at the output of the preamplifier circuit. The high-pass corner frequency created by this capacitor is calculated by Equation 6: 1 F = HP p 2 R44 C (6) The circuit described in Figure 47 is constructed with 1% tolerance resistors and 5% tolerance NP0, C0G ceramic capacitors without any additional hand sorting. The large value of C4 typically requires an electrolytic type to be used. However, electrolytic capacitors have the potential to introduce distortion into the signal path. This circuit is constructed using a bipolar electrolytic capacitor specifically intended for audio applications.

8.2.1.3 Application Curves The deviation from the ideal RIAA transfer function curve is shown in Figure 49 and normalized to an ideal gain of 40 dB at 1 kHz. The measured gain at 1 kHz is 0.05 dB less than the design goal, and the maximum deviation from 100 Hz to 20 kHz is 0.18 dB. The deviation from the ideal curve can be improved by hand-sorting resistor and capacitor values to their ideal values. The value of C4 can also be increased to reduce the deviation at low frequency.

A spectrum of the preamplifier output signal is shown in Figure 50 for a 10 mVRMS, 1-kHz input signal (1-VRMS output). All distortion harmonics are below the preamplifier noise floor.

1.5 0 -10 -20 -30 1 -40 -50 -60 -70 0.5 -80 -90 -100 Magnitude (dB) Magnitude Amplitude (dBV) -110 0 -120 -130 -140 -150 -0.5 -160 10 100 1k 10k 100 1k 10k Frequency (Hz) Frequency (Hz) D202 D201 Figure 49. Measured Deviation From Ideal RIAA Response Figure 50. Output Spectrum for a 10-mVRMS, 1-kHz Input Signal

Copyright © 2019, Texas Instruments Incorporated Submit Documentation Feedback 21 Product Folder Links: OPA1656 OPA1656 SBOS901A –MARCH 2019–REVISED JULY 2019 www.ti.com

Typical Applications (continued) 8.2.2 Composite Headphone Amplifier Figure 51 shows the BUF634A buffer inside the feedback loop of the OPA1656 to increase the available output current for low-impedance headphones. If the BUF634A is used in wide-bandwidth mode, no additional components beyond the feedback resistors are required to maintain loop stability.

12V

100 F 0.1 F

0.1 F

OPA1656 Input + Output 100 œ BUF634A R1 k 0.1 F

0.1 F RBW

100 F

-12V R2 R3

500 500

Copyright © 2019, Texas Instruments Incorporated

Figure 51. Composite Headphone Amplifier (Single-Channel Shown)

8.2.2.1 Application Curves

-85 0 249 W RL 249 W RL 32 W RL -30 -90 16 W RL

-60 -95 -90 -100 THD + N (dB)

Amplitude (dBc) -120

-105 -150

-110 -180 20 Hz 100 Hz 1 kHz 20 kHz 0 5000 10000 15000 20000 Frequency (Hz) Frequency (Hz) C051 C052 Figure 52. THD + N versus Frequency for a 5 VPP(1.77 Figure 53. FFT for 5 VPP(1.77 VRMS), 1-kHz Input Signal VRMS) Input Signal

22 Submit Documentation Feedback Copyright © 2019, Texas Instruments Incorporated Product Folder Links: OPA1656 OPA1656 www.ti.com SBOS901A –MARCH 2019–REVISED JULY 2019

Typical Applications (continued) 8.2.3 Baxandall Tone Control Figure 54 gives an example of ultra-low noise and THD tone control. This circuit provides 20 dB of gain at the first stage, followed by two separate tone controls for bass and treble. The passive circuit is designed to yield a flat gain response with the potentiometers both set to 50%.

Bass 1.69 kΩ 15.4 kΩ 11 kΩ 100 kΩ 11 kΩ

10 µF 10 nF 10 nF œ 11 kΩ +15 Input + 1/2 œ Output 10 µF OPA1656 4.7 nF + 1/2 1.69 kΩ OPA1656 -15

3.65 kΩ 500 kΩ 3.65 kΩ Treble Figure 54. Dual Potentiometer Baxandall Tone Control

8.2.3.1 Application Curves

40 10% Bass / 90% Treble 36 50% Bass / 50% Treble 32 90% Bass / 10% Treble 28 24 20 16 Amplitude (dB) 12 8 4 0 100 1k 10k Frequency (Hz) D203 Figure 55. Amplitude vs Frequency for Various Tone-Control Settings

Copyright © 2019, Texas Instruments Incorporated Submit Documentation Feedback 23 Product Folder Links: OPA1656 24 8.2.4.1 However, the configured rail-to-rail logarithmic noise The 8.2.4 Typical SBOS901A OPA1656 feedback OPA1656 performance. Submit Guitar – Application Applications MARCH this output amplifiers, taper Documentation dc Input of is 2019 an potentiometer blocking the swing – Figure REVISED to excellent Curves noninverting while XLR of (continued) Feedback capacitor 56 the JULY maintaining Output Figure gives

Input Voltage (V) choice Figure ¼ Inch -0.18 -0.16 -0.14 -0.12 -0.08 -0.06 -0.04 -0.02 Jack OPA1656 shown 0.02 0.04 0.06 0.08 2019 -0.1 -0.2 0.1 0 0 stage an can 57. for 56. 0.4 10 µF 10 µF in example very be guitar 1-kHz this to Guitar allows 1 1 0.8 eliminated kΩ Product 1 1 low MΩ remove circuit input 1.2 Input of distortion 1 1 Input for kΩ 100 100 Folder + œ + œ a OPA1656 1.6 provides +5 1 1 circuits -5 kΩ a kΩ basic Signal any 1/2 for OPA1656 10 10 pF 10 10 pF high to Links: 1 1 2 1/2 kΩ applications XLR dc performance. guitar 2.4 as amplitude 6 Transient OPA1656 offset 49 49 49 49 dB a Output 2.8 Ω Ω result Output Voltage 2 Output Voltage 1 Input Voltage input of 3.2 as gain that Output of Schematic swing circuit Simulation XLR a A 3.6 at the are result 10- 0%, Copyright high 4 D200 µ at to not 0.3 2.1 2.4 2.7 3 3.3 -0.9 -0.6 -0.3 0 0.6 0.9 1.2 1.5 -1.2 1.8 F and differential the of dc sensitive input

Output Voltage (V) the blocking © 40 outputs 2019, impedance dB amplifier Texas to of XLR capacitor of low gain Instruments the schematic. dc offset at and differentially offsets. 100%. is www.ti.com Incorporated ultra-low voltage. used The The in OPA1656 www.ti.com SBOS901A –MARCH 2019–REVISED JULY 2019

9 Power Supply Recommendations The OPA1656 is specified for operation from 4.5 V to 36 V (±2.25 V to ±18 V); many specifications apply from –40°C to +125°C. Parameters that can exhibit significant variance with regard to operating voltage or temperature are presented in the Typical Characteristics section.

10 Layout

10.1 Layout Guidelines For best operational performance of the device, use good printed-circuit board (PCB) layout practices, including: • Noise can propagate into analog circuitry through the power pins of the circuit as a whole and of op amp itself. Bypass capacitors are used to reduce the coupled noise by providing low-impedance power sources local to the analog circuitry. – Connect low-ESR, 0.1-µF ceramic bypass capacitors between each supply pin and ground, placed as close to the device as possible. A single bypass capacitor from V+ to ground is applicable for single- supply applications. • Separate grounding for analog and digital portions of circuitry is one of the simplest and most-effective methods of noise suppression. One or more layers on multilayer PCBs are usually devoted to ground planes. A ground plane helps distribute heat and reduces electromagnetic interference (EMI) noise pickup. Physically separate digital and analog grounds, observing the flow of the ground current. • To reduce parasitic coupling, run the input traces as far away from the supply or output traces as possible. If these traces cannot be kept separate, crossing the sensitive trace perpendicular is much better as opposed to in parallel with the noisy trace.

• Place the external components as close to the device as possible. As illustrated in Figure 58, keeping RF and RG close to the inverting input minimizes parasitic capacitance. • Keep the length of input traces as short as possible. Always remember that the input traces are the most sensitive part of the circuit. • Consider a driven, low-impedance guard ring around the critical traces. A guard ring can significantly reduce leakage currents from nearby traces that are at different potentials. • Cleaning the PCB following board assembly is recommended for best performance. • Any precision integrated circuit can experience performance shifts resulting from moisture ingress into the plastic package. Following any aqueous PCB cleaning process, baking the PCB assembly is recommended to remove moisture introduced into the device packaging during the cleaning process. A low temperature, post- cleaning bake at 85°C for 30 minutes is sufficient for most circumstances.

10.1.1 Power Dissipation The OPA1656 op amp is capable of driving 600-Ω loads with a power-supply voltage up to ±18 V and full operating temperature range. Internal power dissipation increases when operating at high supply voltages. Copper leadframe construction used in the OPA1656 improves heat dissipation compared to conventional materials. Circuit board layout can also help minimize junction temperature rise. Wide copper traces help dissipate the heat by acting as an additional heat sink. Temperature rise can be further minimized by soldering the devices to the circuit board rather than using a socket.

Copyright © 2019, Texas Instruments Incorporated Submit Documentation Feedback 25 Product Folder Links: OPA1656 OPA1656 SBOS901A –MARCH 2019–REVISED JULY 2019 www.ti.com

10.2 Layout Example

VIN A + VIN B + RG VOUT A RG VOUT B

RF RF

(Schematic Representation)

Place components Output A Use low-ESR, close to device and to VS+ each other to reduce ceramic bypass parasitic errors. capacitor. Place as close to the device as possible.

OUTPUT A V+ GND RF Output B GND -IN A OUTPUT B RG RF VIN A +IN A -IN B GND RG Vœ +IN B VIN B

Keep input traces short Use low-ESR, and run the input traces ceramic bypass GND VSœ as far away from capacitor. Place as Ground (GND) plane on another layer the supply lines close to the device as possible. as possible.

Figure 58. Operational Amplifier Board Layout for Noninverting Configuration

26 Submit Documentation Feedback Copyright © 2019, Texas Instruments Incorporated Product Folder Links: OPA1656 OPA1656 www.ti.com SBOS901A –MARCH 2019–REVISED JULY 2019

11 Device and Documentation Support

11.1 Device Support

11.1.1 Development Support

11.1.1.1 TINA-TI™ (Free Software Download) TINA™ is a simple, powerful, and easy-to-use circuit simulation program based on a SPICE engine. TINA-TI™ is a free, fully-functional version of the TINA software, preloaded with a library of macro models in addition to a range of both passive and active models. TINA-TI provides all the conventional DC, transient, and frequency domain analysis of SPICE, as well as additional design capabilities. Available as a free download from the WEBENCH® Design Center, TINA-TI offers extensive post-processing capability that allows users to format results in a variety of ways. Virtual instruments offer the ability to select input waveforms and probe circuit nodes, voltages, and waveforms, creating a dynamic quick-start tool.

NOTE These files require that either the TINA software (from DesignSoft™) or TINA-TI software be installed. Download the free TINA-TI software from the TINA-TI folder.

11.1.1.2 DIP Adapter EVM The DIP Adapter EVM tool provides an easy, low-cost way to prototype small surface mount devices. The evaluation tool these TI packages: D or U (SOIC-8), PW (TSSOP-8), DGK (VSSOP-8), DBV (SOT-23-6, SOT-23- 5 and SOT-23-3), DCK (SC70-6 and SC70-5), and DRL (SOT563-6). The DIP Adapter EVM may also be used with terminal strips or may be wired directly to existing circuits.

11.1.1.3 Universal Operational Amplifier EVM The Universal Op Amp EVM is a series of general-purpose, blank circuit boards that simplify prototyping circuits for a variety of device package types. The evaluation module board design allows many different circuits to be constructed easily and quickly. Five models are offered, with each model intended for a specific package type. PDIP, SOIC, VSSOP, TSSOP and SOT-23 packages are all supported.

NOTE These boards are unpopulated, so users must provide their own devices. TI recommends requesting several op amp device samples when ordering the Universal Op Amp EVM.

11.1.1.4 TI Precision Designs TI Precision Designs are analog solutions created by TI’s precision analog applications experts and offer the theory of operation, component selection, simulation, complete PCB schematic and layout, bill of materials, and measured performance of many useful circuits. TI Precision Designs are available online at http://www.ti.com/ww/en/analog/precision-designs/.

11.1.1.5 WEBENCH® Filter Designer WEBENCH® Filter Designer is a simple, powerful, and easy-to-use active filter design program. The WEBENCH Filter Designer allows the user to create optimized filter designs using a selection of TI operational amplifiers and passive components from TI's vendor partners. Available as a web-based tool from the WEBENCH® Design Center, WEBENCH® Filter Designer allows the user to design, optimize, and simulate complete multistage active filter solutions within minutes.

Copyright © 2019, Texas Instruments Incorporated Submit Documentation Feedback 27 Product Folder Links: OPA1656 OPA1656 SBOS901A –MARCH 2019–REVISED JULY 2019 www.ti.com

11.2 Documentation Support

11.2.1 Related Documentation The following documents are recommended for reference when using the OPA1656, and are available for download at www.ti.com. • Texas Instruments, Source Resistance and Noise Considerations in Amplifiers technical brief • Texas Instruments, Single-Supply Operation of Operational Amplifiers application bulletin • Texas Instruments, Op Amp Performance Analysis application bulletin • Texas Instruments, Compensate Transimpedance Amplifiers Intuitively application report • Texas Instruments, Tuning in Amplifiers application bulletin • Texas Instruments, Feedback Plots Define Op Amp AC Performance application bulletin • Texas Instruments, Active Volume Control for Professional Audio design guide

11.3 Receiving Notification of Documentation Updates To receive notification of documentation updates, navigate to the device product folder on ti.com. In the upper right corner, click on Alert me to register and receive a weekly digest of any product information that has changed. For change details, review the revision history included in any revised document.

11.4 Community Resource The following links connect to TI community resources. Linked contents are provided "AS IS" by the respective contributors. They do not constitute TI specifications and do not necessarily reflect TI's views; see TI's Terms of Use. TI E2E™ Online Community TI's Engineer-to-Engineer (E2E) Community. Created to foster collaboration among engineers. At e2e.ti.com, you can ask questions, share knowledge, explore ideas and help solve problems with fellow engineers. Design Support TI's Design Support Quickly find helpful E2E forums along with design support tools and contact information for technical support. 11.5 Trademarks Burr-Brown, TINA-TI, E2E are trademarks of Texas Instruments. WEBENCH is a registered trademark of Texas Instruments. TINA, DesignSoft are trademarks of DesignSoft, Inc. All other trademarks are the property of their respective owners. 11.6 Electrostatic Discharge Caution This integrated circuit can be damaged by ESD. Texas Instruments recommends that all integrated circuits be handled with appropriate precautions. Failure to observe proper handling and installation procedures can cause damage. ESD damage can range from subtle performance degradation to complete device failure. Precision integrated circuits may be more susceptible to damage because very small parametric changes could cause the device not to meet its published specifications.

11.7 Glossary SLYZ022 — TI Glossary. This glossary lists and explains terms, acronyms, and definitions.

12 Mechanical, Packaging, and Orderable Information The following pages include mechanical, packaging, and orderable information. This information is the most current data available for the designated devices. This data is subject to change without notice and revision of this document. For browser-based versions of this data sheet, refer to the left-hand navigation.

28 Submit Documentation Feedback Copyright © 2019, Texas Instruments Incorporated Product Folder Links: OPA1656 PACKAGE OPTION ADDENDUM

www.ti.com 10-Dec-2020

PACKAGING INFORMATION

Orderable Device Status Package Type Package Pins Package Eco Plan Lead finish/ MSL Peak Temp Op Temp (°C) Device Marking Samples (1) Drawing Qty (2) Ball material (3) (4/5) (6) OPA1656ID ACTIVE SOIC D 8 75 RoHS & Green NIPDAU Level-2-260C-1 YEAR -40 to 125 OP1656

OPA1656IDR ACTIVE SOIC D 8 2500 RoHS & Green NIPDAU Level-2-260C-1 YEAR -40 to 125 OP1656

(1) The marketing status values are defined as follows: ACTIVE: Product device recommended for new designs. LIFEBUY: TI has announced that the device will be discontinued, and a lifetime-buy period is in effect. NRND: Not recommended for new designs. Device is in production to support existing customers, but TI does not recommend using this part in a new design. PREVIEW: Device has been announced but is not in production. Samples may or may not be available. OBSOLETE: TI has discontinued the production of the device.

(2) RoHS: TI defines "RoHS" to mean semiconductor products that are compliant with the current EU RoHS requirements for all 10 RoHS substances, including the requirement that RoHS substance do not exceed 0.1% by weight in homogeneous materials. Where designed to be soldered at high temperatures, "RoHS" products are suitable for use in specified lead-free processes. TI may reference these types of products as "Pb-Free". RoHS Exempt: TI defines "RoHS Exempt" to mean products that contain lead but are compliant with EU RoHS pursuant to a specific EU RoHS exemption. Green: TI defines "Green" to mean the content of Chlorine (Cl) and Bromine (Br) based flame retardants meet JS709B low halogen requirements of <=1000ppm threshold. Antimony trioxide based flame retardants must also meet the <=1000ppm threshold requirement.

(3) MSL, Peak Temp. - The Moisture Sensitivity Level rating according to the JEDEC industry standard classifications, and peak solder temperature.

(4) There may be additional marking, which relates to the logo, the lot trace code information, or the environmental category on the device.

(5) Multiple Device Markings will be inside parentheses. Only one Device Marking contained in parentheses and separated by a "~" will appear on a device. If a line is indented then it is a continuation of the previous line and the two combined represent the entire Device Marking for that device.

(6) Lead finish/Ball material - Orderable Devices may have multiple material finish options. Finish options are separated by a vertical ruled line. Lead finish/Ball material values may wrap to two lines if the finish value exceeds the maximum column width.

Important Information and Disclaimer:The information provided on this page represents TI's knowledge and belief as of the date that it is provided. TI bases its knowledge and belief on information provided by third parties, and makes no representation or warranty as to the accuracy of such information. Efforts are underway to better integrate information from third parties. TI has taken and continues to take reasonable steps to provide representative and accurate information but may not have conducted destructive testing or chemical analysis on incoming materials and chemicals. TI and TI suppliers consider certain information to be proprietary, and thus CAS numbers and other limited information may not be available for release.

In no event shall TI's liability arising out of such information exceed the total purchase price of the TI part(s) at issue in this document sold by TI to Customer on an annual basis.

Addendum-Page 1 PACKAGE OPTION ADDENDUM

www.ti.com 10-Dec-2020

Addendum-Page 2 PACKAGE MATERIALS INFORMATION

www.ti.com 16-Oct-2020

TAPE AND REEL INFORMATION

*All dimensions are nominal Device Package Package Pins SPQ Reel Reel A0 B0 K0 P1 W Pin1 Type Drawing Diameter Width (mm) (mm) (mm) (mm) (mm) Quadrant (mm) W1 (mm) OPA1656IDR SOIC D 8 2500 330.0 12.4 6.4 5.2 2.1 8.0 12.0 Q1

Pack Materials-Page 1 PACKAGE MATERIALS INFORMATION

www.ti.com 16-Oct-2020

*All dimensions are nominal Device Package Type Package Drawing Pins SPQ Length (mm) Width (mm) Height (mm) OPA1656IDR SOIC D 8 2500 853.0 449.0 35.0

Pack Materials-Page 2 PACKAGE OUTLINE D0008A SOIC - 1.75 mm max height SCALE 2.800 SMALL OUTLINE INTEGRATED CIRCUIT

C

SEATING PLANE .228-.244 TYP [5.80-6.19] .004 [0.1] C A PIN 1 ID AREA 6X .050 [1.27] 8 1

.189-.197 2X [4.81-5.00] .150 NOTE 3 [3.81]

4X (0 -15 )

4 5 8X .012-.020 [0.31-0.51] B .150-.157 .069 MAX [3.81-3.98] .010 [0.25] CAB [1.75] NOTE 4

.005-.010 TYP [0.13-0.25]

4X (0 -15 )

SEE DETAIL A .010 [0.25]

.004-.010 0 - 8 [0.11-0.25] .016-.050 [0.41-1.27] DETAIL A (.041) TYPICAL [1.04]

4214825/C 02/2019 NOTES:

1. Linear dimensions are in inches [millimeters]. Dimensions in parenthesis are for reference only. Controlling dimensions are in inches. Dimensioning and tolerancing per ASME Y14.5M. 2. This drawing is subject to change without notice. 3. This dimension does not include mold flash, protrusions, or gate burrs. Mold flash, protrusions, or gate burrs shall not exceed .006 [0.15] per side. 4. This dimension does not include interlead flash. 5. Reference JEDEC registration MS-012, variation AA.

www.ti.com EXAMPLE BOARD LAYOUT D0008A SOIC - 1.75 mm max height SMALL OUTLINE INTEGRATED CIRCUIT

8X (.061 ) [1.55] SYMM SEE DETAILS 1 8

8X (.024) [0.6] SYMM

(R.002 ) TYP [0.05] 5 4 6X (.050 ) [1.27] (.213) [5.4]

LAND PATTERN EXAMPLE EXPOSED METAL SHOWN SCALE:8X

SOLDER MASK SOLDER MASK METAL UNDER METAL OPENING OPENING SOLDER MASK

EXPOSED METAL EXPOSED METAL .0028 MAX .0028 MIN [0.07] [0.07] ALL AROUND ALL AROUND

NON SOLDER MASK SOLDER MASK DEFINED DEFINED

SOLDER MASK DETAILS

4214825/C 02/2019

NOTES: (continued)

6. Publication IPC-7351 may have alternate designs. 7. Solder mask tolerances between and around signal pads can vary based on board fabrication site.

www.ti.com EXAMPLE STENCIL DESIGN D0008A SOIC - 1.75 mm max height SMALL OUTLINE INTEGRATED CIRCUIT

8X (.061 ) [1.55] SYMM

1 8

8X (.024) [0.6] SYMM

(R.002 ) TYP 5 [0.05] 4 6X (.050 ) [1.27] (.213) [5.4]

SOLDER PASTE EXAMPLE BASED ON .005 INCH [0.125 MM] THICK STENCIL SCALE:8X

4214825/C 02/2019

NOTES: (continued)

8. Laser cutting apertures with trapezoidal walls and rounded corners may offer better paste release. IPC-7525 may have alternate design recommendations. 9. Board assembly site may have different recommendations for stencil design.

www.ti.com IMPORTANT NOTICE AND DISCLAIMER

TI PROVIDES TECHNICAL AND RELIABILITY DATA (INCLUDING DATASHEETS), DESIGN RESOURCES (INCLUDING REFERENCE DESIGNS), APPLICATION OR OTHER DESIGN ADVICE, WEB TOOLS, SAFETY INFORMATION, AND OTHER RESOURCES “AS IS” AND WITH ALL FAULTS, AND DISCLAIMS ALL WARRANTIES, EXPRESS AND IMPLIED, INCLUDING WITHOUT LIMITATION ANY IMPLIED WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT OF THIRD PARTY INTELLECTUAL PROPERTY RIGHTS. These resources are intended for skilled developers designing with TI products. You are solely responsible for (1) selecting the appropriate TI products for your application, (2) designing, validating and testing your application, and (3) ensuring your application meets applicable standards, and any other safety, security, or other requirements. These resources are subject to change without notice. TI grants you permission to use these resources only for development of an application that uses the TI products described in the resource. Other reproduction and display of these resources is prohibited. No license is granted to any other TI intellectual property right or to any third party intellectual property right. TI disclaims responsibility for, and you will fully indemnify TI and its representatives against, any claims, damages, costs, losses, and liabilities arising out of your use of these resources. TI’s products are provided subject to TI’s Terms of Sale (www.ti.com/legal/termsofsale.html) or other applicable terms available either on ti.com or provided in conjunction with such TI products. TI’s provision of these resources does not expand or otherwise alter TI’s applicable warranties or warranty disclaimers for TI products.

Mailing Address: Texas Instruments, Post Office Box 655303, Dallas, Texas 75265 Copyright © 2020, Texas Instruments Incorporated