Switched Capacitor Instrumentation Amplifier

LTC1043 Dual Precision Instrumentation Switched Capacitor Building Block

FEATURES DESCRIPTIO U ■ Instrumentation Front End with 120dB CMRR The LTC®1043 is a monolithic, charge-balanced, dual ■ Precise, Charge-Balanced Switching switched capacitor instrumentation building block. A pair ■ Operates from 3V to 18V of switches alternately connects an external capacitor to ■ Internal or External Clock an input voltage and then connects the charged capacitor ■ Operates up to 5MHz Clock Rate across an output port. The internal switches have a ■ Low Power break-before-make action. An internal clock is provided ■ Two Independent Sections with One Clock and its frequency can be adjusted with an external capacitor. The LTC1043 can also be driven with an external

APPLICATIOU S CMOS clock. The LTC1043, when used with low clock frequencies, ■ Precision Instrumentation Amplifiers provides ultra precision DC functions without requiring ■ Ultra Precision Voltage Inverters, Multipliers precise external components. Such functions are and Dividers differential voltage to single-ended conversion, voltage ■ V–F and F–V Converters inversion, voltage multiplication and division by 2, 3, 4, 5, ■ Sample-and-Hold etc. The LTC1043 can also be used for precise V–F and ■ Switched Capacitor Filters F–V circuits without trimming, and it is also a building block for switched capacitor filters, oscillators and modulators. The LTC1043 is manufactured using Linear Technology’s enhanced LTCMOSTM silicon gate process. , LTC and LT are registered trademarks of Linear Technology Corporation. LTCMOS is a trademark of Linear Technology Corporation.

TYPICAL APPLICATIO U

Instrumentation Amplifier CMRR vs Frequency

5V 140 C = C = 1µF 4 5V S H 120 3 8 7 8 + 1µF 1 1/2 LTC1013 V 100 C OUT H 2 11 – 4 80 µ DIFFERENTIAL 1 F –5V

C CMRR (dB) INPUT S (EXTERNAL) 60 12 µ 1 F 40

13 14 R1 R2 20 100 1k 10k 100k FREQUENCY OF COMMON MODE SIGNAL 16 1/2 LTC1043 CMRR > 120dB AT DC CMRR > 120dB AT 60Hz LTC1043 • TA02 0.01µF DUAL SUPPLY OR SINGLE 5V 17 GAIN = 1 + R2/R1 LTC1043 • TA01 VOS ≈ 150µV –5V ∆V OS ≈ 2µV/°C ∆T COMMON MODE INPUT VOLTAGE INCLUDES THE SUPPLIES 1043fa 1

LTC1043

W WW U UU

ABSOLUTE AXI U RATI GS PACKAGE/ORDER I FORW ATIO (Note 1) TOP VIEW Supply Voltage ...... 18V ORDER PART + SHB 1 18 S3B NUMBER Input Voltage at Any Pin ...... –0.3V ≤ VIN ≤ V + 0.3V + 2 17 V – Operating Temperature Range CB LTC1043CN C – 3 16 C LTC1043C ...... –40 C T 85 C B OSC LTC1043CSW ° ≤ A ≤ ° V+ 4 15 S4B LTC1043M (OBSOLETE)...... –55°C ≤ TA ≤ 125°C S2B 5 14 S4A Storage Temperature Range ...... –65°C to 150°C S1B 6 13 S3A – Lead Temperature (Soldering, 10 sec)...... 300°C S1A 7 12 CA + S2A 8 11 CA

NC 9 10 SHA

N PACKAGE SW PACKAGE 18-LEAD PDIP 18-LEAD PLASTIC SO TJMAX = 100°C, θJA = 100°C/W PACKAGE (N) TJMAX = 150°C, θJA = 85°C/W PACKAGE (SW) D PACKAGE LTC1043MD 18-LEAD SIDE BRAZED (HERMETIC) OBSOLETE PACKAGE

Consider the N18 Package as an Alternate Source LTC1043 • POI01 Consult LTC Marketing for parts specified with wider operating temperature ranges.

ELECTRICAL CHARACTERISTICS The ● denotes specifications which apply over the full operating temperature + – range, otherwise specifications are at TA = 25°C. V = 10V, V = 0V, LTC1043M operates from –55°C ≤ TA ≤ 125°C; LTC1043C operates from –40°C ≤ TA ≤ 85°C, unless otherwise noted.

LTC1043M LTC1043C SYMBOL PARAMETER CONDITIONS MIN TYP MAX MIN TYP MAX UNITS

IS Power Supply Current Pin 16 Connected High or Low 0.25 0.4 0.25 0.4 mA ● 0.7 0.7 mA – COSC (Pin 16 to V ) = 100pF 0.4 0.65 0.4 0.65 mA ● 11mA

II OFF Leakage Current Any Switch, Test Circuit 1 (Note 2) 6 100 6 100 pA ● 6 500 6 nA

RON ON Resistance Test Circuit 2, VIN = 7V, 1 = ±0.5mA 240 400 240 400 Ω V+ = 10V, V– = 0V ● 700 700 Ω

RON ON Resistance Test Circuit 2, VIN = 3.1V, 1 = ±0.5mA 400 700 400 700 Ω V+ = 5V, V– = 0V ● 11kΩ – fOSC Internal Oscillator Frequency COSC (Pin 16 to V ) = 0pF 185 185 kHz – COSC (Pin 16 to V ) = 100pF 20 34 50 20 34 50 kHz Test Circuit 3 ● 15 75 15 75 kHz + – IOSC Pin Source or Sink Current Pin 16 at V or V 40 70 40 70 µA ● 100 100 µA Break-Before-Make Time 25 25 ns

Clock to Switching Delay COSC Pin Externally Driven 75 75 ns fM Max External CLK Frequency COSC Pin Externally Driven with CMOS Levels 5 5 MHz + – CMRR Common Mode Rejection Ratio V = 5V, V = –5V, –5V < VCM < 5V 120 120 dB DC to 400Hz Note 1: Absolute Maximum Ratings are those values beyond which the life Note 2: OFF leakage current is guaranteed but not tested at 25°C. of a device may be impaired. 1043fa 2 LTC1043

TYPICAL PERFOR A CEUW CHARACTERISTICS (Test Circuits 2 through 4)

Power Supply Current vs Power Supply Voltage RON vs VIN RON vs VIN 1.6 550 + 280 + T = –55°C RON (PEAK) V = 5V RON (PEAK) V = 10V A – – COSC = 0pF 500 V = 0V 260 V = 0V 1.4 ° ° COSC = 0.0047pF I = 100µA TA = 25 C TA = 25 C 450 V 240 V I = 100µA 1.2 IN IN TA = 25°C 400 220 1.0 COSC = 0pF

) 350 ) 200 COSC = 0.0047pF Ω Ω 0.8 ( 300 I = 100µA ( 180 I = 100µA T = 125°C ON ON

A R R 0.6 COSC = 0pF 250 I = mA 160 I = mA C = 0.0047pF OSC 200 140

SUPPLY CURRENT (mA) 0.4 150 120 0.2 100 100 0 0 2610481214 16 18 20 0 1 2 3 4 5 0 1 2 3 4 5 6 7 8 9 10 VSUPPLY (V) VIN (V) VIN (V)

LTC1043 • TPC01 LTC1043 • TPC02 LTC1043 • TPC03

RON (Peak) vs Power Supply RON (Peak) vs Power Supply RON vs VIN Voltage Voltage and Temperature 260 1000 1100 V+ = 15V RON (PEAK) V = 1.6V RON (PEAK) RON (PEAK) 240 V– = 0V 900 IN 1000 TA = 25°C 220 µ 800 900 VIN I = 100 A VIN I = 100µA VIN I = 100µA 200 700 800 ) ) ) 180 600 700 Ω Ω Ω ( ( ( 160 I = 100µA 500 600 TA = 125°C ON ON V ≈ 3.2V ON

R R IN R 140 I = mA 400 500 120 300 V 7V 400 IN ≈ TA = 70°C VIN ≈ 11V 100 200 3V ≤ V+ + ≤18V 300 V– = 0V V 15.1V 80 100 IN ≈ 200 TA = –55°C TA = 25°C 0 100 0 2 4 6 8 10 12 1416 18 20 0 2 4 6 8 10 12 1416 18 20 0 2 4 6 8 10 12 1416 18 20 VIN (V) VSUPPLY (V) VSUPPLY (V)

LTC1043 • TPC04 LTC1043 • TPC05 LTC1043 • TPC06

Oscillator Frequency, fOSC Oscillator Frequency, fOSC Normalized Oscillator Frequency, vs COSC vs Supply Voltage fOSC vs Supply Voltage 1M 250 2.0 TA = 25°C TA = 25°C 0pF < COSC < 0.01µF 225 1.8 TA = 25°C 200 1.6 100k COSC = 0pF 175 1.4 V+ = 10V, V– = 0V

150 AT 5V SUPPLY 1.2 V+ = 5V, V– = 0V (Hz) OSC 10k (kHz) 125 1 OSC OSC f V+ = 15V, V– = 0V f 100 0.8 75 0.6 1k OSCILLATOR FREQUENCY 50 0.4 COSC = 100pF

25 NORMALIZED TO f 0.2 100 0 04k6k8k2k 10k 0 2 4 6 8 10 12 1416 18 20 0 2 4 6 8 10 12 1416 18 20 COSC (pF) VSUPPLY (V) VSUPPLY (V)

LTC1043 • TPC07 LTC1043 • TPC08 LTC1043 • TPC09

1043fa 3 LTC1043

TYPICAL PERFOR A CEUW CHARACTERISTICS (Test Circuits 2 through 4)

Oscillator Frequency, fOSC COSC Pin ISINK, ISOURCE Break-Before-Make Time, tNOV, vs Ambient Temperature, TA vs Supply Voltage vs Supply Voltage 350 100 80 COSC = 0pF TA = 25°C

325 A) µ ISINK, TA = –55°C 70 300 75 275 60 ISINK, TA = 25°C 250 ISOURCE, TA = –55°C 50 (ns) (kHz) 225 50 ISOURCE, TA = 25°C NOV OSC

t 40 f 200 + – 175 V = 10V, V = 0V 30 25 150 + – ISINK, TA = 125°C V = 5V, V = 0V 20 125 + – PIN 16 SOURCE OR SINK CURRENT ( ISOURCE, TA = 125°C V = 15V, V = 0V 100 0 10 –50 –25 0 25 50 75 100 125 0 246810 12 14 16 18 0 2 4 6 8 10 1214 16 18 20 AMBIENT TEMPERATURE (°C) VSUPPLY (V)

LTC1043 • TPC10 LTC1043 • TPC11 LTC1043 • TPC12

BLOCK DIAGRA W

S1A S2A 7 8

+ SHA 10 11 CA

– 12 CA

S3A S4A 13 14

CHARGE BALANCING CIRCUITRY S1B S2B 6 5

+ SHB 1 2 CB

– 3 CB

S3B S4B 18 15 CHARGE BALANCING CIRCUITRY

THE CHARGE BALANCING CIRCUITRY SAMPLES THE VOLTAGE V+ AT S3 WITH RESPECT TO S4 (PIN 16 HIGH) AND INJECTS A + NON-OVERLAPPING 4 SMALL CHARGE AT THE C PIN (PIN 16 LOW). CLOCK THIS BOOSTS THE CMRR WHEN THE LTC1043 IS USED AS AN INSTRUMENTATION AMPLIFIER FRONT END. + – V COSC V FOR MINIMUM CHARGE INJECTION IN OTHER TYPES OF 16 OSCILLATOR 17 APPLICATIONS, S3A AND S3B SHOULD BE GROUNDED V–

THE SWITCHES ARE TIMED AS SHOWN WITH PIN 16 HIGH LTC1043 • BD01

1043fa 4 LTC1043 TEST CIRCUITS

Test Circuit 1. Leakage Current Test Test Circuit 2. RON Test

(7, 13, 6, 18) (8, 14, 5, 15) (7, 13, 6, 18) (8, 14, 5, 15)

NOTE: TO OPEN SWITCHES, A S1 AND S3 SHOULD BE CONNECTED + + TO V–. TO OPEN S2, S4, VIN 0V TO 10V COSC PIN SHOULD BE (11, 12, 2, 3) (11, 12, 2, 3) TO V+ C OSC 100µA to 1mA A LTC1043 • TC01 CURRENT SOURCE

LTC1043 • TC02

Test Circuit 3. Oscillator Frequency, fOSC Test Circuit 4. CMRR Test

78VOUT

V– (TEST PIN) 2 17 10 11 COSC V+ + CAPACITORS ARE 4 LTC1043 16 1 F 1 F + µ µ NOT ELECTROLYTIC

5 12

6 + IV 13 14

LTC1043 • TC03

+ – + V ≤ VCM ≤ V

VCM CMRR = 20 LOG ()VOUT

NOTE: FOR OPTIMUM CMRR, THE COSC SHOULD BE LARGER THAN 0.0047µF, AND THE SAMPLING CAPACITOR ACROSS

PINS 11 AND 12 SHOULD BE PLACED

OVER A SHIELD TIED TO PIN 10 LTC1043 • TC04 UU

APPLICATIO S I FOR ATIOWU

Common Mode Rejection Ratio (CMRR) 1/2 LTC1043 The LTC1043, when used as a differential to single-ended 78 converter rejects common mode signals and preserves differential voltages (Figure 1). Unlike other techniques, C+ 11 the LTC1043’s CMRR does not degrade with increasing + + V C V C common mode voltage frequency. During the sampling D S D H mode, the impedance of Pins 2, 3 (and 11, 12) should be C– 12 reasonably balanced, otherwise, common mode signals will appear differentially. The value of the CMRR depends 13 14 on the value of the sampling and holding capacitors + VCM (CS, CH) and on the sampling frequency. Since the common mode voltages are not sampled, the common mode signal frequency can well exceed the CS, CH ARE MYLAR OR POLYSTRENE sampling frequency without experiencing aliasing LTC1043 • AI01 phenomena. The CMRR of Figure 1 is measured by Figure 1. Differential to Single-Ended Converter 1043fa 5

LTC1043 UU

APPLICATIO S I FOR ATIOWU shorting Pins 7 and 13 and by observing, with a precision Shielding the Sampling Capacitor for Very High CMRR DVM, the change of the voltage across C H with respect to Internal or external parasitic capacitors from the C+ pin(s) an input CM voltage variation. During the sampling and to ground affect the CMRR of the LTC1043 (Figure 1). holding mode, charges are being transferred and minute The common mode error due to the internal junction voltage transients will appear across the holding capaci- capacitances of the C+ Pin(s) 2 and 11 is cancelled through tor. Although the R ON on the switches is low enough to internal circuitry. The C+ pin, therefore, should be used as allow fast settling, as the sampling frequency increases, the top plate of the sampling capacitor. The interpin the rate of charge transfer increases and the average capacitance between pin 2 and dummy Pin 1 (11 and 10) voltage measured with a DVM across it will increase appears in parallel with the sampling capacitor so it does proportionally; this causes the CMRR of the sampled data not degrade the CMRR. A shield placed underneath system, as seen by a “continuous” instrument (DVM), to the sampling capacitor and connected to either Pin 1 or 3 decrease (Figure 2). helps to boost the CMRR in excess of 120dB (Figure 5). Switch Charge Injection Excessive external parasitic capacitance between the C– Figure 3 shows one out of the eight switches of the pins and ground indirectly degrades CMRR; this becomes LTC1043, configured as a basic sample-and-hold circuit. visible especially when the LTC1043 is used with clock When the switch opens, a ‘‘hold step’’ is observed and its frequencies above 2kHz. Because of this, if a shield is magnitude depends on the value of the input voltage. used, the parasitic capacitance between the shield and Figure 4 shows charge injected into the hold capacitor. For circuit ground should be minimized. instance, a 2pCb of charge injected into a 0.01µF capacitor It is recommended that the outer plate of the sampling causes a 200µV hold step. As shown in Figure 4, there is capacitor be connected to the C– pin(s). a predictable and repeatable charge injection cancellation when the input voltage is close to half the supply voltage Input Pins, SCR Sensitivity of the LTC1043. This is a unique feature of this product, An internal 60Ω resistor is connected in series with the containing charge-balanced switches fabricated with a input of the switches (Pins 5, 6, 7, 8, 13, 14, 15, 18) and self-aligning gate CMOS process. Any switch of the it is included in the RON specification. When the input LTC1043, when powered with symmetrical dual supplies, voltage exceeds the power supply by a diode drop, current will sample-and-hold small signals around ground with- will flow into the input pin(s). The LTC1043 will not latch out any significant error. until the input current reaches 2mA–3mA. The device will

140

CS = CH = 1µF 5V 120 CS = 1µF, CZH = 0.1µF 2 6 + 100 1/8 LTC1043 1/2 LTC1013 VOUT

80 – VIN 1000pF –5V CMRR (dB) 60 SAMPLE V+ 40 HOLD TO PIN 16 0V LTC1043 • AI03 20 100 1k 10k 100k fOSC (Hz)

LTC1043 • AI02 Figure 2. CMRR vs Sampling Frequency Figure 3 1043fa 6

LTC1043 UU

APPLICATIO S I FOR ATIOWU recover from the latch mode when the input drops 3V to 4V with an external clock to override the internal oscillator. below the voltage value which caused the latch. For Although standard 7400 series CMOS gates do not instance, if an external resistor of 200Ω is connected in guarantee CMOS levels with the current source and sink series with an input pin, the input can be taken 1.3V above requirements of Pin 16, they will in reality drive the Cosc the supply without latching the IC. The same applies for the pin. CMOS gates conforming to standard B series output C+ and C– pins. drive have the appropriate voltage levels and more than enough output current to simultaneously drive several COSC Pin (16), Figure 6 LTC1043 COSC pins. The typical trip levels of the Schmitt The Cosc pin can be used with an external capacitor, Cosc, trigger (Figure 6) are given below. connected from Pin 16 to Pin 17, to modify the internal oscillator frequency. If Pin 16 is floating, the internal 24pF SUPPLY TRIP LEVELS + – capacitor, plus any external interpin capacitance, set the V = 5V, V = 0V VH = 3.4VVL = 1.35V + – oscillator frequency around 190kHz with ±5V supply. The V = 10V, V = 0V VH = 6.5VVL = 2.8V + – typical performance characteristics curves provide the V = 15V, V = 0V VH = 9.5VVL = 4.1V necessary information to set the oscillator frequency for various power supply ranges. Pin 16 can also be driven

12 V+ = 15V 10 V– = 0V

8 V+ = 10V V– = 0V 6 1 OUTSIDE FOIL 4 V+ = 5V CS 2 CHARGE INJECTION (pCb) V– = 0V 2 3

0 0 264810 12 14 16 PRINTED CIRCUIT BOARD AREA LTC1043 VIN (V) LTC1043 • AI05 LTC1043 • AI04 Figure 4. Individual Switch Charge Injection Figure 5. Printed Circuit Board Layout vs Input Voltage Showing Shielding the Sampling Capacitor

V+ 4

38µF COSC 16 TO CLK GENERATOR

COSC 24pF (EXTERNAL)

17 V–

(24pF) fOSC = 190kHz • (24pF + COSC) LTC1043 * AI06 Figure 6. Internal Oscillator

1043fa 7 LTC1043

TYPICAL APPLICATIO SU

Divide by 2Multiply by 2 Ultra Precision Voltage Inverter

1/2 LTC1043 1/2 LTC1043 1/2 LTC1043 V = –V 7 8 OUT IN VIN 7 8 VOUT = VIN/2 VOUT 7 8 VIN

1µF 11 11 11 1µF 1µF 1µF 1µF 1µF 12 12 12

VIN 13 14 13 14 13 14

16 17 16 17 16 17 0.01µF 0.01µF 0.01µF

VOUT = –VIN ±2ppm – + VOUT = VIN/2 ± 1ppm VOUT = 2VIN ± 5ppm V < VIN < V + + + – 0 ≤ VIN ≤ V 0 ≤ VIN ≤ V /2 V = +5V, V = –5V + + 3 ≤ V ≤ 18V LTC1043 • A01 3 ≤ V ≤ 18V LTC1043 • A02 LTC1043 * A03

Precision Multiply by 3 Precision Multiply by 4 Divide by 3 VIN

LTC1043 LTC1043 LTC1043 V 7 8 7 8 VIN IN 7 8

11 11 11

1µF 1µF 1µF

12 12 12

13 14 13 14 13 14

VOUT

V 2V 1 F OUT 6 5 IN 6 5 VOUT = 4VIN µ 6 5

2 2 2

1µF 1µF 1µF 1µF 1µF 1µF 1µF

3 3 3

18 15 18 15 VOUT 18 15

1µF 16 17 17 16 16 17 0.01µF 0.01µF 0.01µF

VOUT = 3VIN ±10ppm VOUT = 4VIN ±40ppm VOUT = VIN/3 ±3ppm + + + 0 < VIN < V /3 0 ≤ VIN ≤ V /4 0 ≤ VIN ≤ V + + LTC1043 • A06 3V < V < 18V LTC1043 • A04 3V < V < 18V LTC1043 • A05

1043fa 8 LTC1043

TYPICAL APPLICATIO SU

Divide by 4 0.005% V/F Converter

LT1009 –5V 2.5k LTC1043 1k VIN 7 8 17

5V 1/2 LTC1043 11 8 7 1µF 1µF1µF

12 11 fOUT: 0kHz TO 30kHz 14 13 13 14

4 12 16

GAIN 5V 0.01µF 2.5k V 6.19k 6 5 VOUT IN 0V TO 3V – 1 F µ LF356

2 +

1µF1µF –5V

30pF 22k 330k 18 15 Q1 2N2907A 1 F 16 17 µ 0.01µF –5V

LTC1043 • A08

+ 0 ≤ VIN ≤ V VOUT = VIN/4 ±5ppm LTC1043 • A07

0.01% Analog Multiplier

1/4 LTC1043 1k 14 13 –5V

LT1004-1.2V 1µF

12 20k † OUTPUT 5V 0.001µF 80.6k* TRIM 7.5k* 2 7 YINPUT – 6 0.01µF LT1056 1µF 3 + 4 16 5V 1/4 LTC1043 –5V 2 7 XINPUT 6 5 – 6 OUTPUT LT1056 XY ±0.01% 30pF 3 22k 330k + 2 4 OPERATE LTC1043 FROM ±5V † † 2N2907A POLYSTYRENE, MOUNT CLOSE 0.001µF –5V (FOR START-UP) *1% FILM RESISTOR ADJUST OUTPUT TRIM 1µF SO X • Y = OUTPUT ±0.01% –5V LTC1043 • A09

1043fa 9 LTC1043

TYPICAL APPLICATIO SU

Single 5V Supply, Ultra Precision Voltage Controlled Current Source with Instrumentation Amplifier Ground Referred Input and Output

5V 5V LTC1043 INPUT 3 8 + 3 7 0V TO 2V + 7 8 + 1 1/2 LT1013 6 OUTPUT LTC1052 2 A = 1000 2 8 V – – 4 11 1 4 0.1µF0.1µF INPUT 1µF1µF 0.68µF 12

– 100Ω 99.9k 5V 13 14 1k 4 43k + V = 5V 6 5 0.22µF 8 7

10k 2 11 1µF 1N914 1µF NONPOLARIZED 1µF 1µF 100Ω 3 12

18 15 14 13 ≈ –0.5V 1/2 LTC1043 VIN 1OUT = 16 17 4 100Ω INPUT AND OUTPUT VOLTAGE RANGE INCLUDES GROUND. 17 16 5V INPUT REFERRED OFFSET ERRORS ARE TYPICALLY 3µV WITH 1µV OF NOISE ~ 0.0047 CMRR ~ 120dB LTC1043 • A10 0.001µF

OPERATES FROM A SINGLE 5V SUPPLY LTC1043 • A11

Precision Instrumentation Amplifier

CHOPPER AC AMPLIFIER PHASE DC 4 SENSITIVE OUTPUT AMPLIFIER 1/4 LTC1043 1/2 LTC1043 5V DEMODULATOR 1µF 1µF + INPUT 6 5 7 3 7 11 + 1µF 1/4 LTC1043 6 5V LT1056 13 100k 2 8 1M 7 2 2 – 12 – 4 6 100k 100k LT1056 OUTPUT 1µF 1 F µ 14 –5V 3 + 3 4 –5V 100Ω R2 – INPUT 18 15 0.01 100k

OFFSET = 10µV 16 17 –5V R1 DRIFT = 0.1µV/°C 100Ω 0.01µF FULL DIFFERENTIAL INPUT CMRR = 140dB OPEN LOOP GAIN > 108 GAIN = R2/R1 + 1

IBIAS = 1nA LTC1043 • A12

1043fa 10 LTC1043

TYPICAL APPLICATIO SU Lock-In Amplifier (= Extremely Narrow-Band Amplifier)

THERMISTOR BRIDGE SYNCHRONOUS IS THE SIGNAL SOURCE DEMODULATOR

10k* 10k* T1 500Hz SINE DRIVE 4 1 6.19k 6.19k 5V 5V 2 3 – + 5V 6 1/4 LTC1043 LM301A LT1007 13 3 3 8 2 RT 6.19k 2 12 + – 1 1M – 6 V = 1000 • DC 100k LT1012 OUT BRIDGE SIGNAL –5V 3 14 16 –5V + 30pF 4 1µF 100Ω –5V

+ T1 = TF5SX17ZZ, TOROTEL 0.01 F47F µ µ RT = YSI THERMISTOR 44006 ≈ 6.19k AT 37.5°C *MATCH 0.05% PHASE TRIM 6.19k = VISHAY S-102 OPERATE LTC1043 WITH 5V ±5V SUPPLIES 50k 0.002 5V LOCK-IN AMPLIFIER TECHNIQUE 10k 1k 2 + 8 USED TO EXTRACT VERY SMALL SIGNALS BURIED INTO NOISE 7 LT1011 LTC1043 • A013 3 – 4 1

–5V

ZERO CROSSING DETECTOR

50MHz Termal RMS/DC Converter

5V 5V

4 5V 30k* 30k* 1/2 LTC1043 3 8 5V 6 5 + CALIBRATION ADJUST 10k 1 20k 5 LT1013 + 2 7 DC OUTPUT 2 – LT1013 4 100k* 0V TO 3.5V 1µF 1µF 1µF 6 – 3 16 10k 0.01µF 301 * 10k 10k Ω 18 15 0.01µF 10k 300mV 1µF 10VRMS 17 INPUT BRN RED RED N

T2 T2A 1A GRN T1B T2B GRN

2% ACCURACY DC 50MHZ 100:1 CREST FACTOR CAPABILITY

T1 TO T2 = YELLOW SPRINGS INST. CO. LTC1043 • A14 *1% RESISTOR THERMISTOR COMPOSITE ENCLOSE T1 AND T2 IN STYROFOAM

1043fa 11 LTC1043

TYPICAL APPLICATIO SU Quad Single 5V Supply, Low Hold Step, Sample-and-Hold

5V 2 – 4 13 – 1 14 1/4 LT1014 OUTPUT 1/4 LT1014 OUTPUT 3 12 NC 7 8 + NC 6 5 + 11

CL CL 11 0.01µF 2 0.01µF

VIN VIN

6 – 9 – 7 8 1/4 LT1014 OUTPUT 1/4 LT1014 OUTPUT 5 10 NC 13 14 + NC 18 15 +

CL CL 12 0.01µF 3 0.01µF

VIN HOLD VIN LTC1043 • A15 16 17 4 SAMPLE – 5V

FOR 1V ≤ VIN ≤ 4V, THE HOLD STEP IS ≤ 300µV ACQUISITION TIME ~ 8 • RON CH FOR 10-BIT ACCURACY

LTC1043 • A16

Single Supply Precision Linearized Platinum RTD Signal Conditioner

250k* (LINEARITY CORRECTION LOOP) 5V 10k* 5V 3 + 8 2.4k 1 1/2 LT1013 2.74k* 2 – LT1009 4 50k 2.5V ZERO ADJUST

0.1µF 8.25k* 2k 4 0V TO 4V = 0 C TO 400 C 1/2 LTC1043 1/2 LTC1043 ° ° 5 ±0.05°C 7 8 5 6 + 7 1/2 LT1013 6 1k 5k – GAIN 11 2 ADJUST 1µF 1µF 887Ω 1µF 1µF 8.06k* 12 3

1k* 13 14 15 18 Rp 1mA 100Ω AT 0°C 16 17 Rp = ROSEMOUNT 118MFRTD *1% FILM RESISTOR 0.01µF TRIM SEQUENCE: SET SENSOR TO 0°C VALUE. ADJUST ZERO FOR 0V OUT SET SENSOR TO 100°C VALUE. ADJUST GAIN FOR 1,000V OUT SET SENSOR TO 400°C VALUE. ADJUST LINEARITY FOR 4,000V OUT LTC1043 • A17 REPEAT AS REQUIRED

1043fa 12 LTC1043

TYPICAL APPLICATIO SU 0.005% F/V Converter

10k 75k* GAIN TRIM

1µF

1/4 LTC1043 5V 1k –5V 13 14 – LT1004-1.2C 1µF LF356 0V TO 3V OUTPUT

12 +

1000pF –5V 4 5V FREQUENCY IN *75k = TRW # MTR-5/120ppm 16 17 –5V 0kHz TO 30kHz

LTC1043 • A18

High Frequency Clock Tunable Bandpass Filter

R1 10k

R2 10k 10k 5V RIN VIN – 1/2 LTC1043 LT1056 7 8 +

–5V 11 CLOCK 16 200pF 1000pF INPUT BANDPASS 12 OUTPUT 5V 5V 4 13 14 – 1/2 LTC1043

RQ = 10k LT1056 5 6 +

–5V 2 200pF 1000pF 3 fCLK R2 BANDPASS CENTER FREQUENCY fO = • 31.4 R1 5V BANDPASS GAIN AT fO IS: RQ/RIN RQ R2 15 18 – Q = R2 R1 LT1056 fO MAX ≤ 100kHz 17 QMAX AT 100kHz fO IS ≤10 + (fO • Q) MAX ≤ 1MHz f 3MHz, Q < 2 –5V –5V CLK MAX ≤ LTC1043 • A19

1043fa 13 LTC1043

TYPICAL APPLICATIO SU Frequency-Controlled Gain Amplifier

13A 1/2 LTC1043A 14A 13B 1/2 LTC1043B 14B

16A 12A 16B 12B GAIN CONTROL 0.01µF 100pF 0kHz TO 10kHz = GAIN 0 TO 1000 11A 11B

7A 8A 7B 8B

VIN

5V 0.01µF 7 2 – 6 LT1056 VOUT 3 + 4 FOR DIFFERENTIAL INPUT, GROUND PIN 8A AND USE PINS 13A AND 7A FOR INPUTS –5V fIN • 0.01µF GAIN = ; GAIN IS NEGATIVE AS SHOWN 1kHz • 100pF FOR SINGLE-ENDED INPUT AND POSITIVE GAIN, GROUND PIN 8A AND USE PIN 7A FOR INPUT USE ±5V SUPPLIES FOR LTC1043 LTC1043 • A20

Relative Humidity Sensor Signal Conditioner

0.01µF

1/4 LTC1043 8 7

16 –5V 11 17

470k 100pF 1k*

1/4 LTC1043 5V 500 2 7 90% 13 14 – RH TRIM 6 10k 3 LT1056 + 3 6 OUTPUT LM301A 12 + 4 0V TO 1V = 0% TO 100% 2 – 8 1µF 1µF –5V 1

LT1004 SENSOR 22M 9k* 1.2V 100pF

10k 5% RH TRIM 33k

* = 1% FILM RESISTOR SENSOR = PANAMETRICS # RHS 1k* ≈ 500pF AT RH = 76% 1.7 pF/%RH

LTC1043 • A21

1043fa 14 LTC1043

TYPICAL APPLICATIO SU Linear Variable Differential Transformer (LVDT), Signal Conditioner

1/4 LTC1043 0.005µF 0.005µF 7 8 30k

5V 4 5V 30k 11 3 + 8 1 1.5kHz LT1013 RD-BLUE 2 YEL-BLK – 4 100k 5 –5V + OUTPUT BLUE 7 0V ±2.5V AMPLITUDE STABLE 1µF 1/2 LT1013 SINE WAVE SOURCE GRN 0M 2.50M 10k 6 – 4.7k 1N914 200k YEL-RED LT1004 BLK 1.2V Q1 2N4338 LVDT 10k GAIN TRIM + 12 1.2k 7.5k 10µF 17 –5V

13 14 1/4 LTC1043 LVDT = SCHAEVITZ E-100

5V 5V 100k 0.01µF 1k 3 + 8 7 100k LT1011 TO PIN 16, LTC1043 PHASE 2 1 TRIM – 4

–5V LTC1043 • A22

Precision Current Sensing in Supply Rails

IIN SHUNT CAN BE IN POSITIVE OR NEGATIVE SUPPLY LEAD RSHUNT

1/2 LTC1043

7 8 VOUT

11 + 1µF 1µF

13 14

16 17 0.01µF

LTC1043 • A23

1043fa

Information furnished by Linear Technology Corporation is believed to be accurate and reliable. However, no responsibility is assumed for its use. Linear Technology Corporation makes no represen- tation that the interconnection of its circuits as described herein will not infringe on existing patent rights. 15 LTC1043

PACKAGE DESCRIPTIO U

D Package 18-Lead Side Brazed (Hermetic) (Reference LTC DWG # 05-08-1210)

.485 .165 .910 (12.319) (4.191) .020 – .060 .005 (23.114) MAX MAX MAX (0.508 – 1.524) (0.127) MIN 18 17 16 15 14 13 12 11 10

.290 .008 – .015 (7.366) (0.203 – 0.381) TYP PIN NO. 1 .100 .300 .125 .054 IDENT (2.54) (7.620) (3.175) (1.372) 1 2 3 4 5 6 7 8 9 BSC REF MIN .015 – .023 TYP (0.381 – 0.584) D18 0801 OBSOLETE PACKAGE N Package 18-Lead PDIP (Narrow .300 Inch) (Reference LTC DWG # 05-08-1510)

.900* .300 – .325 .130 ± .005 .045 – .065 (22.860) (7.620 – 8.255) (3.302 ± 0.127) (1.143 – 1.651) MAX 18 17 16 15 14 13 12 11 10 .020 (0.508) MIN .065 .008 – .015 .255 ± .015* (1.651) (6.477 ± 0.381) (0.203 – 0.381) TYP +.035 .325 –.015 .120 .005 .100 .018 ± .003 12 +0.889 3 4 567 8 9 8.255 (3.048) (0.127) (2.54) (0.457 ± 0.076) ()–0.381 MIN MIN BSC NOTE: INCHES 1. DIMENSIONS ARE N18 1002 MILLIMETERS *THESE DIMENSIONS DO NOT INCLUDE MOLD FLASH OR PROTRUSIONS. MOLD FLASH OR PROTRUSIONS SHALL NOT EXCEED .010 INCH (0.254mm)

SW Package 18-Lead Plastic Small Outline (Wide .300 Inch) (Reference LTC DWG # 05-08-1620)

.030 ±.005 .050 BSC .045 ±.005 TYP .447 – .463 (11.354 – 11.760) N NOTE 4 18 17 16 15 14 13 12 11 10

N .420 .325 ±.005 MIN

NOTE 3 .394 – .419 (10.007 – 10.643)

123 N/2 NOTE: N/2 INCHES 1. DIMENSIONS IN RECOMMENDED SOLDER PAD LAYOUT (MILLIMETERS) 2. DRAWING NOT TO SCALE 3. PIN 1 IDENT, NOTCH ON TOP AND CAVITIES .291 – .299 1 234 5 6 789 ON THE BOTTOM OF PACKAGES ARE THE (7.391 – 7.595) MANUFACTURING OPTIONS. NOTE 4 .093 – .104 .037 – .045 THE PART MAY BE SUPPLIED WITH OR .010 – .029 × 45° (2.362 – 2.642) (0.940 – 1.143) WITHOUT ANY OF THE OPTIONS (0.254 – 0.737) .005 4. THESE DIMENSIONS DO NOT INCLUDE (0.127) MOLD FLASH OR PROTRUSIONS. RAD MIN MOLD FLASH OR PROTRUSIONS SHALL NOT 0° – 8° TYP EXCEED .006" (0.15mm)

.050 .004 – .012 .009 – .013 (1.270) NOTE 3 BSC (0.102 – 0.305) (0.229 – 0.330) .014 – .019 .016 – .050 (0.356 – 0.482) (0.406 – 1.270) TYP S18 (WIDE) 0502 1043fa Linear Technology Corporation LW/TP 1202 1K REV A ¥ PRINTED IN USA 1630 McCarthy Blvd., Milpitas, CA 95035-7417 16 ● ● (408) 432-1900 FAX: (408) 434-0507 www.linear.com  LINEAR TECHNOLOGY CORPORATION 1985