AD7245AQ

Overview

The AD7245AQ is a monolithic 12-bit voltage output digital-to-analog converter from the DACPORT family, fabricated in LC2MOS technology. It integrates an output amplifier and a buried Zener voltage reference on a single chip, eliminating the need for external user trims. The device features a parallel loading structure with double-buffered interface logic, accepting 12-bit data via DB0–DB11. It operates from supply voltages ranging from +10.8 V to +16.5 V for VDD and -10.8 V to -16.5 V for VSS. Key performance metrics include a settling time of 10 µs to within ±1/2 LSB, a relative accuracy of ±3/4 LSB (max) over the temperature range, and low power consumption of typically 65 mW in single-supply operation.

Feature Summary

• 12-bit resolution with ±3/4 LSB relative accuracy (max) over –40°C to +85°C
• Integrated 5 V buried Zener reference and buffered output amplifier
• Parallel interface with asynchronous LDAC and CLR control signals
• Supports unipolar (0–5 V, 0–10 V) and bipolar (±5 V) output ranges

Applications

• Microprocessor-controlled analog signal generation
• Industrial process control systems requiring precise voltage outputs
• Test and measurement equipment needing stable DAC references
• Multi-channel data acquisition systems using double-buffered updates

Procurement Notes

Verify package authenticity as the AD7245AQ utilizes a 24-lead Cerdip (Q-24) housing. Confirm that the specific grade meets the ±3/4 LSB accuracy requirement, as higher precision variants like the ABN exist. Ensure supply rails are decoupled per datasheet recommendations to maintain reference stability. Check for end-of-life status or alternative sourcing if long-term availability is critical.

Selection Notes

Select the AD7245AQ when a 12-bit parallel DAC with integrated reference and amplifier is required in a through-hole ceramic package. Choose this part over the AD7248A if direct 12-bit parallel data loading is preferred over the 8-bit dual-write interface. Ensure the application supports the specified 12 V to 15 V supply range and requires the extended commercial temperature range of –40°C to +85°C.

Part Context

The AD7245AQ belongs to the enhanced AD7245A series, which improves upon the original industry-standard AD7245 by offering faster interface times, improved linearity grades, and operation from 12 V supplies. It is part of Analog Devices' DACPORT family, designed for space-saving and reliability in single-chip designs compared to multichip solutions. The 'Q' suffix denotes the 24-lead Cerdip package option.

Replacement Considerations

The AD7245ABQ offers improved ±1/2 LSB linearity grade in the same package. For plastic DIP packages, the AD7245AAN is available. Surface mount alternatives include the AD7245AAR (SOIC) and AD7245AAP (PLCC). Verify pin compatibility and electrical specifications before substitution.