AD8556ACPZ-REEL

AD8556ACPZ-REEL FEATURES

EMI filters at input pinsSpecified from −40°C to +140°CLow offset voltage: 10 µV maximumLow input offset voltage drift:65 nV/°C maximumHigh CMRR: 94 dB minimumDigitally programmable gain and output offset voltageProgrammable output clamp voltageOpen and short wire fault detectionLow-pass filteringSingle-wire serial interfaceStable with any capacitive loadSOIC_N and LFCSP_WQ packages4.5 V to 5.5 V operation

AD8556ACPZ-REEL APPLICATIONS

Pressure and position sensorsPrecision current sensingStrain gages

AD8556ACPZ-REEL GENERAL DESCRIPTION

The AD8556 is a zero-drift, sensor signal amplifier withdigitally programmable gain and output offset. Designed toeasily and accurately convert variable pressure sensor andstrain bridge outputs to a well-defined output voltage range,the AD8556 accurately amplifies many other differential orsingle-ended sensor outputs. The AD8556 uses the AnalogDevices, Inc. patented low noise, auto-zero and DigiTrim®technologies to create an incredibly accurate and flexiblesignal processing solution in a very compact footprint.Gain is digitally programmable in a wide range from 70 to1280 through a serial data interface. Gain adjustment canbe fully simulated in-circuit and then permanently pro-grammed with reliable polyfuse technology. Output offsetvoltage is also digitally programmable and is ratiometric tothe supply voltage. The AD8556 also features internal EMIfilters on the VNEG, VPOS, FILT and VCLAMP pins.In addition to extremely low input offset voltage, low input offsetvoltage drift, and very high dc and ac CMRR, the AD8556 alsoincludes a pull-up current source at the input pins and a pull-down current source at the VCLAMP pin, which allows openwire and shorted wire fault detection. A low-pass filter functionis implemented via a single low cost external capacitor. Outputclamping set via an external reference voltage allows the AD8556to drive lower voltage ADCs safely and accurately.When used in conjunction with an ADC referenced to the samesupply, the system accuracy becomes immune to normal supplyvoltage variations. Output offset voltage can be adjusted with aresolution of better than 0.4% of the difference between VDDand VSS. A lockout trim after gain and offset adjustment furtherensures field reliability.The AD8556 is fully specified from −40°C to +140°C.Operating from single-supply voltages of 4.5 V to 5.5 V, theAD8556 is offered in the 8-lead SOIC_N and 4 mm × 4 mm16-lead LFCSP_WQ.Rev. B | Page 3 of 27