AD7718BRU

Overview

The AD7718BRU is a complete analog front-end for low frequency measurement applications, featuring a 24-bit Sigma-Delta ADC. It supports 4/5 fully-differential or 8/10 pseudo-differential input channels with a programmable gain amplifier (PGA) ranging from 1 to 128. The device operates on a single 3 V or 5 V supply, consuming 3.84 mW typically at 3 V. It utilizes a 32 kHz crystal and internal PLL, offering software-programmable output data rates up to 1.365 kS/s. Factory calibration eliminates the need for field adjustments, ensuring high accuracy with integral nonlinearity of ±10 ppm FSR.

Feature Summary

• Factory-calibrated architecture that removes the requirement for external field calibration procedures.
• Integrated rail-to-rail input buffer and programmable gain amplifier for direct transducer signal conversion.
• Simultaneous rejection capabilities for both 50 Hz and 60 Hz power line interference frequencies.
• Configurable VREF Select functionality supporting both absolute and ratiometric measurement modes.

Applications

• Industrial process control systems
• Pressure transducers
• Portable instrumentation devices
• Smart transmitters

Procurement Notes

Verify the specific suffix 'RU' corresponds to the TSSOP-28 package when sourcing. Confirm the temperature grade matches the required operational range of -40°C to +85°C. Ensure the component version aligns with current manufacturing specifications as older revisions may have different electrical characteristics or pinout details.

Selection Notes

Select this model over the AD7708 when 24-bit resolution is required instead of 16-bit. Consider the CHOP mode setting based on whether optimizing for analog performance or channel throughput is the priority. Verify that the available reference voltage range between 1 V and AVDD meets the system design constraints for REFIN inputs.

Part Context

This component belongs to the AD7708/AD7718 family of low voltage, low power ADCs. The AD7718 serves as the 24-bit counterpart to the 16-bit AD7708, sharing identical pinouts and functionality to allow for straightforward hardware upgrades without circuit modifications.

Replacement Considerations

The AD7708BRU is a pin-compatible alternative if 16-bit resolution suffices. No other direct substitutes are documented in the provided datasheet.