Fully-Differential Amplifiers
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1.5A, 24V, 17Mhz Power Operational Amplifier Datasheet (Rev. E)
OPA564 www.ti.com SBOS372E –OCTOBER 2008–REVISED JANUARY 2011 1.5A, 24V, 17MHz POWER OPERATIONAL AMPLIFIER Check for Samples: OPA564 1FEATURES 23• HIGH OUTPUT CURRENT: 1.5A DESCRIPTION • WIDE POWER-SUPPLY RANGE: The OPA564 is a low-cost, high-current operational – Single Supply: +7V to +24V amplifier that is ideal for driving up to 1.5A into reactive loads. The high slew rate provides 1.3MHz – Dual Supply: ±3.5V to ±12V full-power bandwidth and excellent linearity. These • LARGE OUTPUT SWING: 20VPP at 1.5A monolithic integrated circuits provide high reliability in • FULLY PROTECTED: demanding powerline communications and motor control applications. – THERMAL SHUTDOWN – ADJUSTABLE CURRENT LIMIT The OPA564 operates from a single supply of 7V to 24V, or dual power supplies of ±3.5V to ±12V. In • DIAGNOSTIC FLAGS: single-supply operation, the input common-mode – OVER-CURRENT range extends to the negative supply. At maximum – THERMAL SHUTDOWN output current, a wide output swing provides a 20VPP (I = 1.5A) capability with a nominal 24V supply. • OUTPUT ENABLE/SHUTDOWN CONTROL OUT • HIGH SPEED: The OPA564 is internally protected against over-temperature conditions and current overloads. It – GAIN-BANDWIDTH PRODUCT: 17MHz is designed to provide an accurate, user-selected – FULL-POWER BANDWIDTH AT 10VPP: current limit. Two flag outputs are provided; one 1.3MHz indicates current limit and the second shows a – SLEW RATE: 40V/ms thermal over-temperature condition. It also has an Enable/Shutdown pin that can be forced low to shut • DIODE FOR JUNCTION TEMPERATURE down the output, effectively disconnecting the load. MONITORING The OPA564 is housed in a thermally-enhanced, • HSOP-20 PowerPAD™ PACKAGE surface-mount PowerPAD™ package (HSOP-20) with (Bottom- and Top-Side Thermal Pad Versions) the choice of the thermal pad on either the top side or the bottom side of the package. -
Designing Linear Amplifiers Using the IL300 Optocoupler Application Note
Application Note 50 Vishay Semiconductors Designing Linear Amplifiers Using the IL300 Optocoupler INTRODUCTION linearizes the LED’s output flux and eliminates the LED’s This application note presents isolation amplifier circuit time and temperature. The galvanic isolation between the designs useful in industrial, instrumentation, medical, and input and the output is provided by a second PIN photodiode communication systems. It covers the IL300’s coupling (pins 5, 6) located on the output side of the coupler. The specifications, and circuit topologies for photovoltaic and output current, IP2, from this photodiode accurately tracks the photoconductive amplifier design. Specific designs include photocurrent generated by the servo photodiode. unipolar and bipolar responding amplifiers. Both single Figure 1 shows the package footprint and electrical ended and differential amplifier configurations are discussed. schematic of the IL300. The following sections discuss the Also included is a brief tutorial on the operation of key operating characteristics of the IL300. The IL300 photodetectors and their characteristics. performance characteristics are specified with the Galvanic isolation is desirable and often essential in many photodiodes operating in the photoconductive mode. measurement systems. Applications requiring galvanic isolation include industrial sensors, medical transducers, and IL300 mains powered switchmode power supplies. Operator safety 1 8 and signal quality are insured with isolated interconnections. These isolated interconnections commonly use isolation 2 K2 7 amplifiers. K1 Industrial sensors include thermocouples, strain gauges, and pressure transducers. They provide monitoring signals to a 3 6 process control system. Their low level DC and AC signal must be accurately measured in the presence of high 4 5 common-mode noise. -
NTE7144 Integrated Circuit BIMOS Operational Amplifier W/MOSFET Input, Bipolar Output
NTE7144 Integrated Circuit BIMOS Operational Amplifier w/MOSFET Input, Bipolar Output Description: The NTE7144 is an integrated circuit operational amplifier in an 8–Lead Mini–DIP type package that combines the advantages of high–voltage PMOS transistors with high–voltage bipolar transistors on a single monolithic chip. This device features gate–protected MOSFET (PMOS) transistors in the in- put circuit to provide very–high–input impedance, very–low–input current, and high–speed perfor- mance. The NTE7144 operates at supply voltages from 4V to 36V (either single or dual supply) and is internally phase–compensated to achieve stable operation in unity–gain follower operation. The use of PMOS field–effect transistors in the input stage results in common–mode input–voltage capability down to 0.5V below the negative–supply terminal, an important attribute for single–supply applications. The output stage uses bipolar transistors and includes built–in protection against dam- age from load–terminal short–circuiting to either supply–rail or to GND. Features: D MOSFET Input Stage: Very High Input Impedance Very Low Input Current Wide Common–Mode Input Voltage Range Output Swing Complements Input Common–Mode Range D Directly Replaces Industry Type 741 in Most Applications Applications: D Ground–Referenced Single–Supply Amplifiers in Automobile and Portable Instrumentation D Sample and Hold Amplifiers D Long–Duration Timers/Multivibrators (Microseconds – Minutes – Hours) D Photocurrent Instrumentation D Peak Detectors D Active Filters D Comparators D Interface in 5V TTL Systems and other Low–Supply Voltage Systems D All Standard Operational Amplifier Applications D Function Generators D Tone Controls D Power Supplies D Portable Instruments D Intrusion Alarm Systems Absolute Maximum Ratings: DC Supply Voltage (Between V+ and V– Terminals). -
ECE 255, MOSFET Basic Configurations
ECE 255, MOSFET Basic Configurations 8 March 2018 In this lecture, we will go back to Section 7.3, and the basic configurations of MOSFET amplifiers will be studied similar to that of BJT. Previously, it has been shown that with the transistor DC biased at the appropriate point (Q point or operating point), linear relations can be derived between the small voltage signal and current signal. We will continue this analysis with MOSFETs, starting with the common-source amplifier. 1 Common-Source (CS) Amplifier The common-source (CS) amplifier for MOSFET is the analogue of the common- emitter amplifier for BJT. Its popularity arises from its high gain, and that by cascading a number of them, larger amplification of the signal can be achieved. 1.1 Chararacteristic Parameters of the CS Amplifier Figure 1(a) shows the small-signal model for the common-source amplifier. Here, RD is considered part of the amplifier and is the resistance that one measures between the drain and the ground. The small-signal model can be replaced by its hybrid-π model as shown in Figure 1(b). Then the current induced in the output port is i = −gmvgs as indicated by the current source. Thus vo = −gmvgsRD (1.1) By inspection, one sees that Rin = 1; vi = vsig; vgs = vi (1.2) Thus the open-circuit voltage gain is vo Avo = = −gmRD (1.3) vi Printed on March 14, 2018 at 10 : 48: W.C. Chew and S.K. Gupta. 1 One can replace a linear circuit driven by a source by its Th´evenin equivalence. -
Chapter 10 Differential Amplifiers
Chapter 10 Differential Amplifiers 10.1 General Considerations 10.2 Bipolar Differential Pair 10.3 MOS Differential Pair 10.4 Cascode Differential Amplifiers 10.5 Common-Mode Rejection 10.6 Differential Pair with Active Load 1 Audio Amplifier Example An audio amplifier is constructed as above that takes a rectified AC voltage as its supply and amplifies an audio signal from a microphone. CH 10 Differential Amplifiers 2 “Humming” Noise in Audio Amplifier Example However, VCC contains a ripple from rectification that leaks to the output and is perceived as a “humming” noise by the user. CH 10 Differential Amplifiers 3 Supply Ripple Rejection vX Avvin vr vY vr vX vY Avvin Since both node X and Y contain the same ripple, their difference will be free of ripple. CH 10 Differential Amplifiers 4 Ripple-Free Differential Output Since the signal is taken as a difference between two nodes, an amplifier that senses differential signals is needed. CH 10 Differential Amplifiers 5 Common Inputs to Differential Amplifier vX Avvin vr vY Avvin vr vX vY 0 Signals cannot be applied in phase to the inputs of a differential amplifier, since the outputs will also be in phase, producing zero differential output. CH 10 Differential Amplifiers 6 Differential Inputs to Differential Amplifier vX Avvin vr vY Avvin vr vX vY 2Avvin When the inputs are applied differentially, the outputs are 180° out of phase; enhancing each other when sensed differentially. CH 10 Differential Amplifiers 7 Differential Signals A pair of differential signals can be generated, among other ways, by a transformer. -
Example of a MOSFET Operational Amplifier
Example of a MOSFET Operational Amplifier: This circuit is one I “designed” as an example for Engineering 1620. It is certainly not fully optimized and I am not sure it is free of errors. It is based on a 1.5 micron, P-well process and therefore uses an N-channel differential pair for its input. This is somewhat unusual because P-channel devices have lower intrinsic noise and are the device-type of choice for the input stage. I did this simply to avoid doing your SPICE assignment for you. The overall properties of the circuit are given in the table below. Amplifier Property Value A0 – DC Gain 86 DB (X20,000) fp – dominant pole position 400 Hz fGBW 8.0 MHz fU – unity gain frequency 5.6 MHz Output stage resistance at low frequency 277 K Zero position 10.7 MHz Slew Rate 710 6 V/sec Output stage quiescent current 65 a Opamp quiescent current 103 a Bias circuit quiescent current 104 a Total system quiescent current 210 a VDD 5.0 volts Total system power 1.1 mW MOSFET Operational Amplifier Gain and Phase 10 0 18 0 80 12 0 60 Gain 60 Phase 40 0 Gain (DB) 20 -60 Phase (deg.) 0 -120 -20 -180 1.00E+02 1.00E+03 1.00E+04 1.00E+05 1.00E+06 1.00E+07 1.00E+08 Frequency (Hz) Phase margin = 60 deg. Parameter Table for MOSFET Opamp Example element model vds vgs vth vov id gm ro m1 nssb 0.748 0.851 0.547 0.304 3.77E-05 2.90E-04 5.54E+05 m10 nssb 3.368 0.851 0.547 0.304 4.12E-05 3.11E-04 8.09E+05 m12 nssb 0.711 0.711 0.546 0.165 3.51E-05 5.01E-04 5.05E+05 m13 nssb 0.838 0.851 0.547 0.304 3.79E-05 2.91E-04 5.92E+05 m14 nssb 3.078 1.079 0.840 0.239 3.51E-05 -
AN55 Power Supply Bypassing for High-Voltage Operational Amplifiers
AN55 Power Supply Bypassing for High-Voltage Operatinal Amplifiers POWER SUPPLY BYPASSING FOR HIGH-VOLTAGE OPERATIONAL AMPLIFIERS With the introduction of Apex’s high-voltage amplifiers like PA89 and PA99, new issues arise in the realm of circuit board layout and power supply bypassing. Working with these amplifiers, designers quickly realize that the same rules do not apply between bypassing high- and low-voltage Op-Amps. This applications infor- mation is meant to assist in designing the bypass system in a high-voltage operational amplifier circuit and choosing the perfect capacitors for use in such designs. THE NEED FOR POWER SUPPLY BYPASSING Before finding a couple of high-voltage capacitors and tacking them onto your supply rails, it is vital to realize the purpose of these capacitors and what we need them to do. Power supply bypass capacitors are there to stabilize the supply voltages of a circuit. Logically, the next question to answer would be, “What causes supply voltages to change?” This list can go on, but the most common reasons for changing supply voltages are power interruptions, high-frequency voltage/current spikes, and high-current draws. Figure 1: Power Supply Rejection Chart of PA89 100 80 60 40 20 WŽǁĞƌ^ƵƉƉůLJZĞũĞĐƟŽŶ͕W^Z;ĚͿ 0 1 10100 1k 10k 100k1M 10M Frequency, F (Hz) The first two entries on the list can be lumped into one category called “high-frequency events.” One close look at the datasheet for PA89 yields the Power Supply Rejection chart. As the frequency increases, power supply rejection falls off rather quickly. For example, if the power supply rail experiences a 100 kHz spike, then as much as 1% of that high-frequency voltage change will show up on the output. -
Differential Amplifiers
www.getmyuni.com Operational Amplifiers: The operational amplifier is a direct-coupled high gain amplifier usable from 0 to over 1MH Z to which feedback is added to control its overall response characteristic i.e. gain and bandwidth. The op-amp exhibits the gain down to zero frequency. Such direct coupled (dc) amplifiers do not use blocking (coupling and by pass) capacitors since these would reduce the amplification to zero at zero frequency. Large by pass capacitors may be used but it is not possible to fabricate large capacitors on a IC chip. The capacitors fabricated are usually less than 20 pf. Transistor, diodes and resistors are also fabricated on the same chip. Differential Amplifiers: Differential amplifier is a basic building block of an op-amp. The function of a differential amplifier is to amplify the difference between two input signals. How the differential amplifier is developed? Let us consider two emitter-biased circuits as shown in fig. 1. Fig. 1 The two transistors Q1 and Q2 have identical characteristics. The resistances of the circuits are equal, i.e. RE1 = R E2, RC1 = R C2 and the magnitude of +VCC is equal to the magnitude of �VEE. These voltages are measured with respect to ground. To make a differential amplifier, the two circuits are connected as shown in fig. 1. The two +VCC and �VEE supply terminals are made common because they are same. The two emitters are also connected and the parallel combination of RE1 and RE2 is replaced by a resistance RE. The two input signals v1 & v2 are applied at the base of Q1 and at the base of Q2. -
INA106: Precision Gain = 10 Differential Amplifier Datasheet
INA106 IN A1 06 IN A106 SBOS152A – AUGUST 1987 – REVISED OCTOBER 2003 Precision Gain = 10 DIFFERENTIAL AMPLIFIER FEATURES APPLICATIONS ● ACCURATE GAIN: ±0.025% max ● G = 10 DIFFERENTIAL AMPLIFIER ● HIGH COMMON-MODE REJECTION: 86dB min ● G = +10 AMPLIFIER ● NONLINEARITY: 0.001% max ● G = –10 AMPLIFIER ● EASY TO USE ● G = +11 AMPLIFIER ● PLASTIC 8-PIN DIP, SO-8 SOIC ● INSTRUMENTATION AMPLIFIER PACKAGES DESCRIPTION R1 R2 10kΩ 100kΩ 2 5 The INA106 is a monolithic Gain = 10 differential amplifier –In Sense consisting of a precision op amp and on-chip metal film 7 resistors. The resistors are laser trimmed for accurate gain V+ and high common-mode rejection. Excellent TCR tracking 6 of the resistors maintains gain accuracy and common-mode Output rejection over temperature. 4 V– The differential amplifier is the foundation of many com- R3 R4 10kΩ 100kΩ monly used circuits. The INA106 provides this precision 3 1 circuit function without using an expensive resistor network. +In Reference The INA106 is available in 8-pin plastic DIP and SO-8 surface-mount packages. Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of Texas Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet. All trademarks are the property of their respective owners. PRODUCTION DATA information is current as of publication date. Copyright © 1987-2003, Texas Instruments Incorporated Products conform to specifications per the terms of Texas Instruments standard warranty. Production processing does not necessarily include testing of all parameters. www.ti.com SPECIFICATIONS ELECTRICAL ° ± At +25 C, VS = 15V, unless otherwise specified. -
A Differential Operational Amplifier Circuit Collection
Application Report SLOA064A – April 2003 A Differential Op-Amp Circuit Collection Bruce Carter High Performance Linear Products ABSTRACT All op-amps are differential input devices. Designers are accustomed to working with these inputs and connecting each to the proper potential. What happens when there are two outputs? How does a designer connect the second output? How are gain stages and filters developed? This application note answers these questions and gives a jumpstart to apprehensive designers. 1 INTRODUCTION The idea of fully-differential op-amps is not new. The first commercial op-amp, the K2-W, utilized two dual section tubes (4 active circuit elements) to implement an op-amp with differential inputs and outputs. It required a ±300 Vdc power supply, dissipating 4.5 W of power, had a corner frequency of 1 Hz, and a gain bandwidth product of 1 MHz(1). In an era of discrete tube or transistor op-amp modules, any potential advantage to be gained from fully-differential circuitry was masked by primitive op-amp module performance. Fully- differential output op-amps were abandoned in favor of single ended op-amps. Fully-differential op-amps were all but forgotten, even when IC technology was developed. The main reason appears to be the simplicity of using single ended op-amps. The number of passive components required to support a fully-differential circuit is approximately double that of a single-ended circuit. The thinking may have been “Why double the number of passive components when there is nothing to be gained?” Almost 50 years later, IC processing has matured to the point that fully-differential op-amps are possible that offer significant advantage over their single-ended cousins. -
9 Op-Amps and Transistors
Notes for course EE1.1 Circuit Analysis 2004-05 TOPIC 9 – OPERATIONAL AMPLIFIER AND TRANSISTOR CIRCUITS . Op-amp basic concepts and sub-circuits . Practical aspects of op-amps; feedback and stability . Nodal analysis of op-amp circuits . Transistor models . Frequency response of op-amp and transistor circuits 1 THE OPERATIONAL AMPLIFIER: BASIC CONCEPTS AND SUB-CIRCUITS 1.1 General The operational amplifier is a universal active element It is cheap and small and easier to use than transistors It usually takes the form of an integrated circuit containing about 50 – 100 transistors; the circuit is designed to approximate an ideal controlled source; for many situations, its characteristics can be considered as ideal It is common practice to shorten the term "operational amplifier" to op-amp The term operational arose because, before the era of digital computers, such amplifiers were used in analog computers to perform the operations of scalar multiplication, sign inversion, summation, integration and differentiation for the solution of differential equations Nowadays, they are considered to be general active elements for analogue circuit design and have many different applications 1.2 Op-amp Definition We may define the op-amp to be a grounded VCVS with a voltage gain (µ) that is infinite The circuit symbol for the op-amp is as follows: An equivalent circuit, in the form of a VCVS is as follows: The three terminal voltages v+, v–, and vo are all node voltages relative to ground When we analyze a circuit containing op-amps, we cannot use the -
Transistor Basics
Transistor Basics: Collector The schematic representation of a transistor is shown to the left. Note the arrow pointing down towards the emitter. This signifies it's an NPN transistor (current flows in the direction of the arrow). See the Q1 datasheet at: www.fairchildsemi.com. Base 2N3904 A transistor is basically a current amplifier. Say we let 1mA flow into the base. We may get 100mA flowing into the collector. Note: The Emitter currents flowing into the base and collector exit through the emitter (the sum off all currents entering or leaving a node must equal zero). The gain of the transistor will be listed in the datasheet as either βDC or Hfe. The gain won't be identical even in transistors with the same part number. The gain also varies with the collector current and temperature. Because of this we will add a safety margin to all our base current calculations (i.e. if we think we need 2mA to turn on the switch we'll use 4mA just to make sure). Sample circuit and calculations (NPN transistor): Let's say we want to heat a block of metal. One way to do that is to connect a power resistor to the block and run current through the resistor. The resistor heats up and transfers some of the heat to the block of metal. We will use a transistor as a switch to control when the resistor is heating up and when it's cooling off (i.e. no current flowing in the resistor). In the circuit below R1 is the power resistor that is connected to the object to be heated.