The AD8557 is a zero drift, sensor signal amplifier with digitally programmable gain and output offset. Designed to easily and accurately convert variable pressure sensor and strain bridge outputs to a well defined output voltage range, the AD8557 accurately amplifies many other differential or single-ended sensor outputs. The AD8557 uses the ADI-patented low noise auto-zero and DigiTrim® technologies to create an accurate and flexible signal processing solution in a compact footprint.
Gain is digitally programmable in a wide range from 28 to 1300 through a serial data interface. Gain adjustment can be fully simulated in circuit and then permanently programmed with reliable polyfuse technology. Output offset voltage is also digitally programmable and is ratiometric to the supply voltage.
In addition to extremely low input offset voltage and input offset voltage drift and very high dc and ac CMRR, the AD8557 also includes a pull-up current source at the input pins and a pull-down current source at the VCLAMP pin. Output clamping set via an external reference voltage allows the AD8557 to drive lower voltage ADCs safely and accurately.
When used in conjunction with an ADC referenced to the same supply, the system accuracy becomes immune to normal supply voltage variations. Output offset voltage can be adjusted with a resolution of better than 0.4% of the difference between VDD and VSS. A lockout trim after gain and offset adjustment further ensures field reliability.
The AD8557 is fully specified from −40°C to +125°C. Operating from single-supply voltages of 2.7 V to 5.5 V, the AD8557 is offered in an 8-lead SOIC_N, and a 4 mm × 4 mm, 16-lead LFCSP_VQ.Applications
|Title||Content Type||File Type|
|AD8557: Digitally Programmable Sensor Signal Amplifier Data Sheet (Rev C, 06/2011) (pdf, 700 kB)||Data Sheets|
|A Designer's Guide to Instrumentation Amplifiers (3rd Edition)||Design Handbooks||HTML|
(doc, 75 kB)
A wide variety of electronic applications, especially those involving very small input signals, require signal paths with very low offset voltage and offset voltage drift over time and temperature.
High-performance Adder Uses Instrumentation Amplifiers
Make an adder circuit using instrumentation amplifiers to increase input impedance.
|Leading Inside Advertorials: Applying Instrumentation Amplifiers EffectivelyThe Importance of an Input Ground Return (pdf, 121 kB)||Overview|
|RAQs index||Rarely Asked Questions||HTML|
|Glossary of EE Terms||Glossary||HTML|
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The USA list pricing shown is for BUDGETARY USE ONLY, shown in United States dollars (FOB USA per unit for the stated volume), and is subject to change. International prices may differ due to local duties, taxes, fees and exchange rates. For volume-specific price or delivery quotes, please contact your local Analog Devices, Inc. sales office or authorized distributor. Pricing displayed for Evaluation Boards and Kits is based on 1-piece pricing.