AD7781CRUZ

Overview

The AD7781CRUZ is a 20-bit sigma-delta analog-to-digital converter featuring an integrated programmable gain amplifier and internal clock. It operates on a single supply voltage ranging from 2.7 V to 5.25 V with typical current consumption of 115 μA at unity gain and 330 μA at maximum gain. The device supports pin-programmable filter responses, offering update rates of either 10 Hz or 16.7 Hz. It utilizes a 16-lead TSSOP package and communicates via a SPI-compatible serial interface.

Feature Summary

• Pin-programmable configuration for gain selection and filter response without software overhead
• Integrated low-noise programmable gain amplifier supporting gains of 1 or 128
• Internal oscillator eliminates the need for external clock components
• Built-in bridge power-down switch enables significant power savings in sensor applications

Applications

• Weigh scales
• Pressure measurement systems
• Industrial process control instrumentation
• Portable battery-operated devices

Procurement Notes

Verify the specific grade (B or C) required for noise performance specifications before ordering. Confirm that the 16-lead TSSOP package matches the target PCB footprint. Ensure the design accommodates the independent digital and analog supply requirements if DVDD differs from AVDD.

Selection Notes

Select this component for high-resolution bridge sensor interfaces requiring minimal external circuitry. Evaluate the RMS noise and peak-to-peak resolution tables against the specific reference voltage and gain settings. Consider the settling time constraints when designing for high-speed data acquisition versus high-rejection filtering needs.

Part Context

This part belongs to the Analog Devices AD7781 family of precision ADCs. It is designed as a complete front-end solution for resistive bridge sensors. The CRUZ suffix indicates the commercial temperature range variant housed in a 16-lead TSSOP package, distinct from industrial or military grade options.

Replacement Considerations

AD7781BRUZ is a confirmed substitute within the same manufacturer line, differing primarily in the specified noise performance grades.