AD8555ACPZ-R2

Overview

The AD8555ACPZ-R2 is a zero-drift, sensor signal amplifier featuring digitally programmable gain and output offset. It utilizes low noise auto-zero and DigiTrim technologies to achieve high accuracy in a compact footprint. The device operates on single supply voltages from 2.7 V to 5.5 V and supports an extended industrial temperature range of −40°C to +125°C. Key electrical specifications include a maximum input offset voltage of 10 µV, a maximum input offset voltage drift of 60 nV/°C, and a minimum common-mode rejection ratio (CMRR) of 96 dB. Gain is digitally programmable from 70 to 1,280 via a single-wire serial interface.

Feature Summary

• Digitally programmable gain and output offset voltage using poly-fuse technology for permanent storage.
• Integrated open and short wire fault detection with pull-up and pull-down current sources at input pins.
• Low-pass filtering capability implemented via a single external capacitor connected to the FILT/DIGOUT pin.
• Externally programmable output clamp voltage allows safe driving of lower voltage analog-to-digital converters.

Applications

• Pressure and position sensors
• Thermocouple amplifiers
• Industrial weigh scales
• Precision current sensing
• Strain gages

Procurement Notes

Verify the specific suffix 'R2' against official Analog Devices documentation to confirm packaging details, as datasheets primarily reference standard LFCSP-16 configurations. Ensure compatibility with required programming interfaces and verify that the component meets all absolute maximum ratings for your specific operating conditions before integration.

Selection Notes

Select this component when designing systems requiring high precision with minimal calibration overhead. The integrated auto-zero architecture eliminates the need for external chopper-stabilized circuits. Consider the digital interface requirements for gain and offset adjustments, and ensure the available package size fits within the board layout constraints for the target application.

Part Context

The AD8555 belongs to Analog Devices' family of zero-drift instrumentation amplifiers designed for sensor signal conditioning. It integrates a two-stage amplifier architecture with digital potentiometers for gain control. The device is optimized for applications where long-term stability and low noise are critical, providing a complete solution for converting small differential sensor signals into usable voltage ranges.

Replacement Considerations

Consult the official ordering guide for verified substitute part numbers. Cross-reference pinouts and electrical specifications carefully when considering alternative packages or variants within the same product family.

FAQ

How is the gain programmed on the AD8555?

Gain is adjusted via a single-wire serial interface using the DIGIN pin. Values can be simulated in-circuit and permanently stored using poly-fuse technology.

What is the function of the VCLAMP pin?

The VCLAMP pin sets the output clamp voltage. This feature limits the output swing to protect downstream components, such as low-voltage ADCs, from overvoltage conditions.

How does the device detect wiring faults?

The AD8555 includes pull-up currents at the VPOS and VNEG inputs to detect open wires, and internal comparators detect shorted wires to VDD or VSS, clamping the output to VSS upon fault detection.