AD7864ASZ-3

Overview

The AD7864ASZ-3 is a high-speed, low-power, 4-channel simultaneous sampling 12-bit analog-to-digital converter (ADC) manufactured by Analog Devices. It operates from a single 5 V supply and features four track-and-hold amplifiers with an internal 2.5 V reference and on-chip clock oscillator. The device supports ±2.5 V input voltage ranges and offers overvoltage protection on analog inputs. It utilizes a successive approximation architecture with a conversion time of 1.65 μs per channel. The maximum throughput is 500 kSPS for a single channel and 130 kSPS for all four channels. It employs a high-speed parallel interface compatible with 3 V processors.

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 power-saving standby mode reduces typical power dissipation to 20 μW.
• High-speed parallel interface facilitates direct connection to microprocessors and DSPs.

Applications

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

Procurement Notes

Verify the specific suffix -3 indicates the ±2.5 V input range variant when sourcing. Confirm package integrity for the 44-lead MQFP form factor. Ensure compatibility with single 5 V supply requirements. Check datasheet revisions for any updates to timing characteristics or absolute maximum ratings prior to integration.

Selection Notes

Select this component for applications requiring simultaneous sampling of four channels with 12-bit resolution. Consider the ±2.5 V input range suitability for signal conditioning circuits. Evaluate the 90 mW typical power consumption against system thermal constraints. Verify processor interface speed matches the 500 kSPS single-channel throughput capability.

Part Context

The AD7864 series includes variants with different input ranges: AD7864-1 for ±10 V/±5 V, AD7864-2 for unipolar 0 V to 2.5 V/5 V, and AD7864-3 for ±2.5 V. All share the same core ADC architecture and pinout. The ASZ-3 designation specifies the industrial temperature range and lead-free packaging within the MQFP format.

Replacement Considerations

Direct pin-compatible substitutes are not explicitly listed in the provided documentation. Cross-reference with other Analog Devices 4-channel SAR ADCs if input range or throughput specifications differ. Verify interface logic levels and power supply requirements before substituting.