AD7245AAP

Overview

The AD7245AAP is a monolithic 12-bit voltage-output digital-to-analog converter from Analog Devices, featuring an integrated output amplifier and a buried Zener voltage reference. It operates on single or dual supplies ranging from +10.8 V to +16.5 V for VDD and -10.8 V to -16.5 V for VSS. The device utilizes a parallel loading structure with double-buffered interface logic, accepting 12-bit data via DB0-DB11. Key performance metrics include a typical settling time of 7 µs to within ±1/2 LSB, relative accuracy grades of ±3/4 LSB (A version) or ±1/2 LSB (B version), and low power consumption of approximately 65 mW in single-supply mode. It is housed in a 28-lead Plastic Leaded Chip Carrier (PLCC) package.

Feature Summary

• Integrated 12-bit DACPORT architecture with on-chip output amplifier and 5 V buried Zener reference.
• Parallel interface with double-buffered latches; asynchronous LDAC updates analog output.
• Configurable output ranges: 0 V to 5 V, 0 V to 10 V (single supply), or ±5 V (dual supply).
• Extended commercial temperature range (-40°C to +85°C) with improved linearity grades.

Applications

• Microprocessor-controlled instrumentation systems requiring direct interfacing.
• Programmable gain amplifiers and variable voltage references.
• Waveform generation and signal processing circuits.
• Industrial control loops utilizing single or dual supply rails.

Procurement Notes

Verify the specific linearity grade suffix (AA vs AB) required for the application, as this determines the relative accuracy specification. Confirm that the 28-lead PLCC package option aligns with the PCB footprint design. Ensure power supply decoupling at the REF OUT pin meets the datasheet recommendations to maintain reference stability and noise performance.

Selection Notes

Select the AD7245AAP when a surface-mount PLCC package is preferred over DIP or SOIC options. Choose the AA suffix for ±3/4 LSB accuracy or AB for ±1/2 LSB accuracy at 25°C. Verify that the system requires the internal reference; if external precision references are needed, consider alternative models. Ensure the parallel interface timing constraints (setup/hold times) match the microprocessor capabilities.

Part Context

The AD7245AAP belongs to the enhanced AD7245A/AD7248A family, which improves upon the legacy AD7245/AD7248 by offering operation from 12 V to 15 V supplies and faster interface times. While the AD7248A uses an 8-bit wide bus with two write cycles, the AD7245A accepts full 12-bit parallel data in a single cycle. The 'P' suffix specifically denotes the 28-lead Plastic Leaded Chip Carrier package variant.

Replacement Considerations

Direct pin-compatible replacements within the same package include other AD7245A variants such as AD7245AAN (DIP), AD7245AAR (SOIC), or AD7245AAQ (Cerdip). For higher accuracy requirements, the AD7245AB series offers ±1/2 LSB linearity. If extended temperature range (-55°C to +125°C) is needed, the AT/AE versions are available, though availability may be restricted to military processing.