AD7890BR-2

ADCs/DACs - Special Purpose Overview

The AD7890BR-2 is an 8-channel, 12-bit data acquisition system fabricated in LC2MOS technology. It integrates a multiplexer, track/hold amplifier, ADC, and 2.5 V reference on a single chip. Operating from a single 5 V supply, it accepts analog input ranges of 0 V to 2.5 V. The device features a high-speed serial interface and supports both self-clocking and external clocking modes. Key electrical parameters 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 separate access to MUX OUT for external antialiasing filtering
• On-chip 2.5 V voltage reference with external reference input capability
• High-speed bidirectional serial interface compatible with microcontrollers and DSPs
• Low-power operation with 30 mW typical dissipation and 75 μW standby mode

ADCs/DACs - Special Purpose Applications

• Industrial process control systems requiring multi-channel signal acquisition
• Data logging equipment with moderate sampling rate requirements
• Battery-powered instrumentation benefiting from low standby current
• Automotive sensor interfaces operating within specified temperature ranges

ADCs/DACs - Special Purpose Procurement Notes

Verify the specific suffix 'B' indicates the commercial temperature range (-40°C to +85°C) and the '-2' denotes the 0 V to 2.5 V input range. Confirm package availability (SOIC or DIP) matches the target PCB design. Check RoHS compliance status as manufacturing processes may vary by production lot. Ensure ordering documentation specifies the required revision level if legacy support is needed.

ADCs/DACs - Special Purpose Selection Notes

Select this component when an 8-channel multiplexed input is required with a unipolar 0 V to 2.5 V range. The B version is suitable for commercial applications requiring -40°C to +85°C operation. Consider the AD7890-10 for bipolar ±10 V inputs or the AD7890-4 for 0 V to 4.096 V ranges. Evaluate the need for external clocking versus self-clocking modes based on the host processor's serial port capabilities.

ADCs/DACs - Special Purpose Part Context

The AD7890 belongs to Analog Devices' specialized data acquisition family. It utilizes Linear Compatible CMOS (LC2MOS) technology to combine precision analog circuits with low-power digital logic. The BR-2 variant specifically targets cost-sensitive commercial applications with standard temperature constraints. It serves as a complete subsystem solution, reducing board space compared to discrete multiplexer and ADC combinations.

ADCs/DACs - Special Purpose Replacement Considerations

Direct pin-compatible replacements within the same series include the AD7890ANZ-2 (DIP package) or AD7890ARZ-2 (SOIC package). For different input ranges, consider the AD7890-4 or AD7890-10 variants. Verify that any substitute maintains the same serial interface timing and control register structure to ensure software compatibility.