AD7864AS-2

Overview

The AD7864ASZ-2 is a high-speed, low-power, 4-channel simultaneous sampling analog-to-digital converter (ADC) from Analog Devices. It features a 12-bit resolution with a maximum throughput of 500 kSPS per channel and 130 kSPS for all four channels. The device operates on a single 5 V supply, consuming typically 90 mW in normal mode and 20 μW in standby. It includes four track-and-hold amplifiers with an acquisition time of 0.35 μs and a conversion time of 1.65 μs. The AD7864-2 variant supports unipolar input ranges of 0 V to 2.5 V or 0 V to 5 V. It utilizes a high-speed parallel interface compatible with 3 V processors and offers overvoltage protection on analog inputs.

Feature Summary

• Four simultaneously sampled inputs preserve relative phase information across channels.
• Hardware or software selectable channel sequence allows conversion of any subset of the four channels.
• Integrated 2.5 V reference and on-chip clock oscillator simplify system design.
• High-speed parallel interface facilitates easy connection to microprocessors and DSPs.

Applications

• AC motor control
• Uninterrupted power supplies
• Data acquisition systems
• Communications

Procurement Notes

Verify the specific suffix 'ASZ-2' against the manufacturer's current ordering guide to confirm pinout compatibility and input range specifications. Ensure that the 44-lead MQFP package dimensions match your PCB footprint requirements. Confirm RoHS compliance status through official documentation before finalizing procurement decisions.

Selection Notes

Select the AD7864ASZ-2 when unipolar input signals within the 0 V to 2.5 V or 0 V to 5 V range are required. This model is suitable for applications needing simultaneous sampling of four channels with high aperture delay matching. Consider the internal reference and clock if external components are to be minimized. Evaluate power consumption constraints against the typical 90 mW normal mode dissipation.

Part Context

The AD7864 series comprises four-channel simultaneous sampling ADCs available in different input range variants. The AD7864-1 supports bipolar ±10 V and ±5 V ranges, while the AD7864-3 supports ±2.5 V. The AD7864-2 specifically addresses unipolar applications. All variants share the same core architecture, including the 12-bit SAR ADC and parallel interface, differing primarily in input scaling circuitry.

Replacement Considerations

Direct functional substitutes include other Analog Devices 4-channel simultaneous sampling ADCs such as the AD7864-1 or AD7864-3, provided the input voltage range matches the application requirements. Cross-vendor replacements require careful evaluation of pin compatibility, interface timing, and input range specifications.