AD7788ARMZ

Overview

The AD7788ARMZ is a low-power, 16-bit sigma-delta analog-to-digital converter (ADC) from Analog Devices Inc. It operates on a single supply voltage ranging from 2.5 V to 5.25 V, with a maximum normal-mode current of 75 µA and power-down current of 1 µA. The device features an internal clock oscillator and provides simultaneous 50 Hz and 60 Hz rejection at a fixed output update rate of 16.6 Hz. Key electrical specifications include a typical RMS noise of 1.5 µV, integral nonlinearity of ±15 ppm of full-scale range (FSR), and offset error of ±3 µV. It utilizes a 3-wire serial interface compatible with SPI, QSPI, MICROWIRE, and DSP standards.

Feature Summary

• Integrated sigma-delta modulation with on-chip digital filtering for high-resolution measurements
• Internal clock oscillator eliminates the need for external clock sources
• Schmitt-triggered serial clock input supports opto-isolated applications
• Built-in VDD monitor channel for power supply supervision

Applications

• Smart transmitters
• Battery-powered portable instrumentation
• Precision sensor measurement systems
• Weigh scales
• 4 to 20 mA loop receivers

Procurement Notes

Verify the specific grade (A or B) required for your application temperature range before ordering. The AD7788ARMZ suffix indicates the MSOP package. Confirm that the supply voltage range aligns with the selected grade specifications. Ensure the reference voltage requirements match the device's operational limits. Check for any specific calibration needs based on the factory calibration conditions defined in the datasheet.

Selection Notes

Select the AD7788ARMZ when 16-bit resolution is sufficient for the application, offering lower cost compared to the 24-bit AD7789 variant. Consider the 16.6 Hz update rate if simultaneous 50/60 Hz line frequency rejection is critical. Evaluate the power consumption constraints, as the device draws only 75 µA in normal mode. Ensure the system can accommodate the bipolar or unipolar coding options available via the mode register configuration.

Part Context

The AD7788ARMZ belongs to the AD7788/AD7789 family of low-power, low-noise analog front ends designed for low-frequency measurement applications. It shares the same pinout, interface, and core architecture as the higher-resolution AD7789 but offers 16-bit effective resolution. This family is optimized for battery-operated devices where power efficiency and noise performance are paramount.

Replacement Considerations

The AD7789 serves as a higher-resolution alternative within the same package and interface ecosystem. Direct pin-compatible substitutes may exist among other 16-bit sigma-delta ADCs, but verification of register compatibility and timing characteristics is required. No other specific replacement part numbers are confirmed in the public documentation.