AD7225KN

Overview

The AD7225KN is a monolithic CMOS quad 8-bit digital-to-analog converter featuring integrated output buffer amplifiers. It operates with supply voltages ranging from 11.4 V to 16.5 V on VDD and -5 V on VSS, supporting single or dual supply configurations. The device provides four independent voltage outputs with separate reference inputs for each channel, allowing flexible signal conditioning. Key electrical specifications include a settling time of 4 µs to ±½ LSB, differential nonlinearity of ±1 LSB, and integral nonlinearity of ±1 LSB. The interface utilizes an 8-bit parallel data bus with double-buffered registers for simultaneous multi-channel updates.

Feature Summary

• Quad 8-bit DAC architecture with integrated unity-gain output amplifiers
• Separate reference input terminals (VREFA–VREFD) for each channel
• Double-buffered interface logic enabling simultaneous update via LDAC
• TTL and CMOS compatible digital inputs with parallel data bus

Applications

• Programmable transversal filters requiring multi-channel synchronization
• Digital word multiplication systems utilizing multiple DAC channels
• Microprocessor-controlled analog signal generation with unipolar/bipolar outputs

Procurement Notes

Verify the specific suffix 'KN' against the manufacturer's ordering guide to confirm package type and temperature range. Ensure power supply rails match the specified 11.4 V to 16.5 V range for VDD and -5 V for VSS to maintain guaranteed performance parameters. Confirm pinout compatibility with the target PCB layout, particularly regarding AGND and DGND separation.

Selection Notes

Select this component when four independent 8-bit voltage outputs are required on a single chip. The AD7225 supports both single-supply (15 V) and dual-supply (-5 V/+15 V) operation; dual supplies offer improved zero-code error and sink capability. Ensure the reference voltage source can drive the minimum 11 kΩ input impedance across all codes. Verify that the application requires parallel interface control rather than serial alternatives.

Part Context

The AD7225 belongs to the Analog Devices LC2MOS family of high-speed linear-compatible CMOS data converters. This process technology integrates precision analog circuitry with high-speed digital logic on a single die. The device is part of a broader portfolio including higher resolution variants like the AD7245, offering a cost-effective solution for mid-performance multi-channel applications.

Replacement Considerations

Direct pin-compatible replacements within the same package may be limited due to specific suffix variations. Check the AD7225 ordering guide for alternative packages such as SOIC, SSOP, or PLCC if lead-free or surface-mount options are required. Cross-reference with Maxim Integrated MX7225 series for functional equivalence in legacy designs.