AD7891ASZ-1REEL

ADCs/DACs - Special Purpose Overview

The AD7891ASZ-1REEL is an LC2MOS-based, 8-channel, 12-bit high-speed data acquisition system manufactured by Analog Devices. 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 supports ±5 V or ±10 V input ranges with a maximum sample rate of 454.5 kSPS. The device features selectable parallel or serial interfaces via the MODE pin, ensuring compatibility with microprocessors. Typical power dissipation is 82 mW in normal mode, reducing to 75 mW in standby.

ADCs/DACs - Special Purpose Feature Summary

• Integrates 8 single-ended analog input channels with overvoltage protection (±17 V for AD7891-1).
• Supports both parallel and serial interface modes selectable via the MODE pin.
• Includes an on-chip 2.5 V reference and track/hold amplifier.
• Delivers 12-bit resolution with ±1 LSB relative accuracy and 1.6 µs conversion time.

ADCs/DACs - Special Purpose Applications

• Data Acquisition Systems
• Motor Control
• Mobile Communication Base Stations
• Instrumentation

ADCs/DACs - Special Purpose Procurement Notes

Verify the 'Z' suffix indicates Pb-free compliance per the ordering guide. Confirm the '-1' designation matches the required ±5 V or ±10 V bipolar input range. Ensure the REEL packaging aligns with automated assembly requirements. Check RoHS status as specifications may vary by production batch.

ADCs/DACs - Special Purpose Selection Notes

Select the AD7891ASZ-1REEL for applications requiring bipolar inputs up to ±10 V. Choose this model over the -2 variant if unipolar ranges are not sufficient. Verify that the MQFP-44 package fits the PCB footprint. Ensure the system operates within the -40°C to +85°C commercial temperature range specified for the A version.

ADCs/DACs - Special Purpose Part Context

This component belongs to the AD7891 family of octal 12-bit SAR ADCs. The ASZ-1REEL variant specifically denotes the Plastic Quad Flatpack (MQFP) package, Pb-free construction, and reel packaging format. It is part of the industrial-grade lineup designed for monolithic data acquisition integration.

ADCs/DACs - Special Purpose Replacement Considerations

Direct substitutes include other AD7891 variants such as AD7891AS-1REEL or AD7891AP-1REEL, provided the package type and lead-free status match the design constraints. Cross-model selection depends on specific input range and accuracy requirements.

ADCs/DACs - Special Purpose FAQ

How is the interface mode selected?

The interface mode is determined by the logic level on the MODE pin. A logic high selects parallel mode, while a logic low selects serial mode.

What is the maximum sample rate for the AD7891-1?

The AD7891-1 achieves a maximum sample rate of 454.5 kSPS when operated in parallel interface mode.

Can the internal reference be bypassed?

Yes. An external reference voltage can be applied to the REF OUT/REF IN pin to override the internal 2.5 V reference.