AD7738BRU

Overview

The AD7738BRU is an 8-channel, high throughput, 24-bit sigma-delta analog-to-digital converter (ADC) from Analog Devices Inc. It features a high-precision analog front end with configurable inputs supporting eight single-ended or four fully differential channels. The device offers unipolar and bipolar input ranges of ±625 mV, ±1.25 V, and ±2.5 V. It operates with a 5 V analog supply and a 3 V or 5 V digital supply. The part supports data rates up to 15.4 kHz and includes on-chip per-channel system calibration. It is housed in a 28-lead TSSOP package and specified for operation over the extended industrial temperature range of –40°C to +105°C.

Feature Summary

• Configurable analog front end supporting eight single-ended or four fully differential input channels.
• On-chip per-channel system calibration options for enhanced accuracy.
• Differential reference input featuring 'No-Reference' detect capability.
• Multiplexer output pinned out externally to allow programmable gain or signal conditioning.

Applications

• PLCs/DCS
• Multiplexing Applications
• Process Control
• Industrial Instrumentation

Procurement Notes

Verify the specific ordering suffix RU-28 corresponds to the 28-lead TSSOP package configuration. Confirm that the component meets the required extended industrial temperature specifications of –40°C to +105°C for your application environment. Ensure compatibility with the intended 5 V analog and 3 V or 5 V digital supply voltages before finalizing procurement.

Selection Notes

Select this component when high-resolution multiplexing is required with fast channel switching capabilities. Consider the trade-off between noise performance and data throughput, as the device allows balancing these parameters via the digital interface. Verify that the available input ranges and common-mode voltage requirements align with the sensor signals being monitored.

Part Context

The AD7738 belongs to the AD7738 family of high-precision analog front ends. Related parts include the AD7734, which features four single-ended input channels with true bipolar input ranges to ±10 V, and the AD7732, which provides two fully differential input channels. These variants share similar operational principles but differ in channel count and input configurations.

Replacement Considerations

Public confirmed substitute part numbers are not provided in the source material.

FAQ

What is the maximum data throughput rate supported by the AD7738?

The AD7738 can be configured via a simple digital interface to balance noise performance against data throughput, supporting rates up to 15.4 kHz.

How does the AD7738 handle reference voltage detection?

The differential reference input features a 'No-Reference' detect capability, which alerts the system if the reference voltage is missing or out of specification.

Can external signal conditioning be implemented with the AD7738?

Yes, the multiplexer output is pinned out externally, allowing users to implement programmable gain or signal conditioning before applying the input to the ADC.