ANALOG DEVICES AD8657 Service Manual

18 V, Precision, Micropower

FEATURES

Micropower at high voltage (18 V): 18 A typical Low offset voltage: 350 µV maximum Single-supply operation: 2.7 V to 18 V Dual-supply operation: ±1.35 V to ±9 V Low input bias current: 20 pA Gain bandwidth: 200 kHz Unity-gain stable Excellent electromagnetic interference immunity

APPLICATIONS

Portable operating systems Current monitors 4 mA to 20 mA loop drivers Buffer/level shifting Multipole filters Remote/wireless sensors Low power transimpedance amplifiers

GENERAL DESCRIPTION

The AD8657 is a dual, micropower, precision, rail-to-rail input/output amplifier optimized for low power and wide operating supply voltage range applications.

The AD8657 operates from 2.7 V up to 18 V with a typical quiescent supply current of 18 μA. It uses the Analog Devices, Inc., patented DigiTrim® trimming technique, which achieves low offset voltage. The AD8657 also has high immunity to electromagnetic interference.

The combination of low supply current, low offset voltage, very low input bias current, wide supply range, and rail-to-rail input and output makes the AD8657 ideal for current monitoring and current loops in process and motor control applications. The combination of precision specifications makes this device ideal for dc gain and buffering of sensor front ends or high impedance input sources in wireless or remote sensors or transmitters.

The AD8657 is specified over the extended industrial temperature range (−40°C to +125°C) and is available in an 8-lead MSOP package and an 8-lead LFCSP package.

CMOS RRIO Operational Amplifier

AD8657

PIN CONFIGURATION

OUT A 1

–IN A 2 +IN A 3

AD8657

TOP VIEW

(Not to Scale)

V– 4

Figure 1. 8-Lead MSOP

UT A

AD8657

2–IN A

TOP VIEW

3+IN A

(Not to Scale)

4V–

NOTES

1. IT IS RE COMMENDED TO CONNECT THE EXPOSED PAD TO V–.

Figure 2. 8-Lead LFCSP

Table 1. Micropower Op Amps

Supply Voltage 5 V 12 V to 16 V 36 V

Single AD8500 AD8663 ADA4505-1 AD8505 AD8541 AD8603 Dual AD8502 AD8667 OP295 ADA4505-2 OP281 ADA4062-2 AD8506 AD8542 AD8607 Quad AD8504 AD8669 OP495 ADA4505-4 OP481 ADA4062-4 AD8508 AD8544 AD8609

V+8 OUT B7 –IN B6 +IN B5

8V+ 7OUT B 6 –IN B 5 +IN B

08804-001

08804-061

Rev. A

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