AD7890AR-2

ADCs/DACs - Special Purpose Overview

The AD7890AR-2 is an 8-channel, 12-bit serial data acquisition system fabricated in LC2MOS technology. It integrates an input multiplexer, track/hold amplifier, ADC, and a 2.5 V reference on a single chip. Designed for single 5 V supply operation, it supports an analog input range of 0 V to 2.5 V. The device features a high-speed bidirectional serial interface and allows separate access to the multiplexer output for external signal conditioning. Key specifications include a maximum conversion time of 5.9 μs, a typical power dissipation of 30 mW in normal mode, and a standby power consumption of 75 μW.

ADCs/DACs - Special Purpose Feature Summary

• Integrated 8-channel multiplexer with independent MUX OUT access for external antialiasing filtering
• On-chip 2.5 V voltage reference and track/hold amplifier
• High-speed serial interface compatible with microcontrollers and DSPs
• Low-power operation: 30 mW typical (normal mode), 75 μW typical (standby mode)

ADCs/DACs - Special Purpose Applications

• Industrial process control systems requiring multi-channel data acquisition
• Data logging applications with moderate speed requirements
• Embedded measurement systems interfacing with serial digital ports

ADCs/DACs - Special Purpose Procurement Notes

Verify the specific suffix 'AR-2' against the manufacturer's current ordering guide to confirm package type (SOIC or PDIP) and temperature grade. Ensure the design utilizes the correct 0 V to 2.5 V input range configuration. Check for RoHS compliance status if required by local regulations, as older revisions may differ.

ADCs/DACs - Special Purpose Selection Notes

Select the AD7890AR-2 when an 8-channel solution with a unipolar 0 V to 2.5 V input range is required. Choose this part over the AD7890-10 or AD7890-4 if the application signals are within the 2.5 V limit. Consider the separate MUX OUT pin if a single shared antialiasing filter is desired across all channels to reduce component count.

ADCs/DACs - Special Purpose Part Context

The AD7890 belongs to Analog Devices' specialized data acquisition family. It is available in multiple versions distinguished by input range (-10 for ±10 V, -4 for 0–4.096 V, -2 for 0–2.5 V) and package/temperature options (A, B, S). The AR-2 variant specifically denotes the 0–2.5 V range version in a plastic surface-mount or through-hole package.

ADCs/DACs - Special Purpose Replacement Considerations

Direct functional replacements within the same family include AD7890AR-4 (0–4.096 V range) and AD7890AR-10 (±10 V range), provided the input voltage levels are adjusted accordingly. Verify that the pinout and serial interface timing remain compatible with the existing design.