AD7890BR-4

ADCs/DACs - Special Purpose Overview

The AD7890BR-4 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. The device operates from a single 5 V supply with a maximum power dissipation of 50 mW in normal mode and 75 μW in standby. It features a conversion time of 5.9 μs max at a 2.5 MHz clock. The AD7890-4 variant accepts unipolar analog inputs ranging from 0 V to 4.096 V and outputs straight binary code. It supports both self-clocking and external clocking serial interfaces for microcontroller connectivity.

ADCs/DACs - Special Purpose Feature Summary

• Integrated 8-channel multiplexer with separate access to MUX OUT for external antialiasing filtering
• 12-bit resolution with 5.9 μs maximum conversion time and 2 μs track/hold acquisition time
• On-chip 2.5 V voltage reference with 0 V to 4.096 V input range for the -4 variant
• Flexible high-speed serial interface supporting self-clocking (master) and external clocking (slave) modes

ADCs/DACs - Special Purpose Applications

• Industrial process control systems requiring multi-channel signal acquisition
• Data acquisition modules for microcontrollers and DSP processors
• Battery-powered instrumentation benefiting from low-power standby mode
• Automotive sensor interface circuits

ADCs/DACs - Special Purpose Procurement Notes

Verify the suffix 'BR' indicates the 24-lead Small Outline package (SOIC_W) and temperature grade. Confirm the '-4' suffix specifies the 0 V to 4.096 V input range. Ensure the source document matches the Rev. C datasheet for accurate timing and electrical specifications. Check pinout compatibility if replacing older revisions.

ADCs/DACs - Special Purpose Selection Notes

Select the AD7890BR-4 when a unipolar 0 V to 4.096 V input range is required. Choose this part over the AD7890-10 or AD7890-2 if the application does not need bipolar ±10 V or 0 V to 2.5 V ranges. Consider the separate MUX OUT pin if a single shared antialiasing filter is desired across all channels. Verify that the system clock can support up to 2.5 MHz for optimal performance.

ADCs/DACs - Special Purpose Part Context

The AD7890 series belongs to Analog Devices' family of monolithic data acquisition systems. The BR suffix denotes the plastic small outline package. The -4 designation specifically sets the internal signal scaling for a 0 V to 4.096 V input window, utilizing the on-chip 2.5 V reference. This model is distinct from the -10 (bipolar) and -2 (low voltage unipolar) variants.

ADCs/DACs - Special Purpose Replacement Considerations

Direct substitutes include other AD7890 variants (-10, -2) if input ranges differ. Cross-model replacements like the AD7891 offer similar functionality but may have different pinouts or performance specs. Verify package dimensions and pin assignments before substitution.