AD7794BRU-REEL

Overview

The AD7794BRU-REEL is a low-power, low-noise analog front end featuring a 24-bit sigma-delta ADC with six differential inputs. It integrates a programmable gain instrumentation amplifier (1 to 128), an internal bandgap reference, and excitation current sources. The device operates on a 2.7 V to 5.25 V supply, consuming 400 μA typical current. Output data rates range from 4.17 Hz to 470 Hz. It supports simultaneous 50 Hz/60 Hz rejection and includes a low-side power switch for sensor power management. The B-grade part functions within a temperature range of −40°C to +105°C.

Feature Summary

• Integrates a 24-bit sigma-delta ADC with a low-noise programmable gain instrumentation amplifier.
• Includes an internal precision bandgap reference and programmable excitation current sources.
• Features a low-side power switch to minimize system power consumption between conversions.
• Supports independent digital and analog power supplies for flexible interface compatibility.

Applications

• Temperature measurement
• Pressure measurement
• Weigh scales
• Strain gage transducers
• Industrial process control

Procurement Notes

Verify the specific ordering suffix against the manufacturer's official documentation to confirm package type and reel specifications. Ensure the component grade matches the required operating temperature range for the target application environment. Cross-reference the datasheet revision to validate all electrical parameters before finalizing procurement orders.

Selection Notes

Select this component for high-precision applications requiring multiple differential channels and integrated signal conditioning. Consider the internal reference accuracy and drift characteristics when external references are not utilized. Evaluate the available output data rates against the required noise performance and system bandwidth constraints.

Part Context

This component belongs to the AD7794/AD7795 family of complete analog front ends designed for high-precision measurement applications. The AD7794 variant provides 24-bit resolution, while the AD7795 offers 16-bit resolution. Both share identical pinouts and functional blocks, differing primarily in converter resolution and associated noise specifications.

Replacement Considerations

Public confirmed substitute part numbers: AD7124-8BCPZ.

FAQ

Can the AD7794 operate with separate analog and digital supply voltages?

Yes, the device features independent AVDD and DVDD pins, allowing the serial interface to operate at a different voltage level than the analog section.

What is the function of the PSW pin?

The PSW pin controls a low-side power switch that can be used to power down bridge sensors between conversions to minimize system power consumption.

How does the device handle 50 Hz and 60 Hz line interference?

The ADC provides simultaneous 50 Hz and 60 Hz rejection capabilities through its digital filter settings, selectable via the mode register.