AD7789BRM

Overview

The AD7789BRM is a low-power, 24-bit Sigma-Delta analog-to-digital converter (ADC) manufactured by Analog Devices Inc. It operates on a single supply voltage ranging from 2.5 V to 5.25 V and features an internal clock oscillator that provides a nominal output update rate of 16.6 Hz. This update rate enables simultaneous rejection of 50 Hz and 60 Hz line frequencies. The device incorporates one differential input channel and supports a reference voltage range from 0.1 V to VDD. Key electrical specifications include a maximum normal-mode current consumption of 75 µA, a power-down current of 1 µA maximum, and an RMS noise level of 1.5 µV typical.

Feature Summary

• Integrated Sigma-Delta modulator with digital filtering for high-resolution signal conversion
• Internal clock oscillator eliminating the need for external clock sources
• Simultaneous 50 Hz and 60 Hz line frequency rejection capabilities
• 3-wire serial interface compatible with SPI, QSPI, MICROWIRE, and DSP systems

Applications

• Smart transmitters
• Battery-powered instrumentation
• Portable measurement devices
• Sensor measurement systems
• Temperature and pressure measurement
• Weigh scales
• 4 to 20 mA loop monitoring

Procurement Notes

Verify component authenticity through authorized distributors or direct manufacturer channels. Confirm the specific B-grade temperature rating (-40°C to +105°C) matches application requirements. Check datasheet revisions for any updates to absolute maximum ratings or timing characteristics before finalizing procurement documentation.

Selection Notes

Select the AD7789BRM when 24-bit resolution and ultra-low power consumption are critical. Ensure the system design accommodates the 16.6 Hz fixed output data rate. Verify that the external reference voltage falls within the 0.1 V to VDD range. Consider the 10-lead MSOP package dimensions for PCB layout constraints.

Part Context

The AD7789BRM belongs to the AD7788/AD7789 family of low-power, low-noise analog front ends designed for low-frequency measurement applications. While the AD7789 offers 24-bit resolution, the AD7788 variant provides 16-bit resolution. Both share identical pinouts, interfaces, and general operational characteristics within the same package.

Replacement Considerations

The AD7789BRMZ serves as a direct replacement for the AD7789BRM, offering identical electrical performance in a lead-free MSOP-10 package. Verify RoHS compliance requirements if transitioning between these suffixes.