AD7247ABN

Overview

The AD7247ABN is a dual 12-bit voltage-output Digital-to-Analog Converter (DAC) from Analog Devices, housed in a 24-pin plastic DIP package. It integrates on-chip output amplifiers and a Zener voltage reference, eliminating the need for external trimming. The device features a parallel loading structure with separate Chip Select inputs for each DAC and a common Write input. It operates from single (+12 V to +15 V) or dual supplies (±12 V to ±15 V). Key electrical specifications include a typical settling time of 8 µs, a relative accuracy of ±0.5 LSB, and a power dissipation of approximately 165 mW in single-supply mode.

Feature Summary

• Dual 12-bit CMOS DAC architecture with integrated output amplifiers and internal 5 V reference.
• Parallel interface with independent Chip Select (CSA/CSB) and common Write (WR) inputs for direct microprocessor connection.
• Configurable output ranges: 0 V to +5 V, 0 V to +10 V (unipolar), and ±5 V (bipolar via REF IN connection).
• Industrial temperature range (-40 °C to +85 °C) with ±0.5 LSB maximum relative accuracy.

Applications

• Direct interfacing with 8-bit and 16-bit microprocessors such as Intel 8086 and Motorola 68000.
• Multi-channel data acquisition systems requiring simultaneous or independent analog output generation.
• Precision instrumentation requiring low power consumption and high linearity without external component trimming.

Procurement Notes

Verify the specific suffix 'N' confirms the plastic DIP-24 package variant. Confirm that the 'B' grade meets the required ±0.5 LSB relative accuracy specification for the target operating temperature range of -40 °C to +85 °C. Ensure supply voltages remain within the +10.8 V to +16.5 V range for specified performance.

Selection Notes

Select the AD7247ABN over the AD7237A when a native 12-bit parallel interface is preferred over an 8-bit double-buffered structure. This model simplifies logic design by providing dedicated Chip Select lines for each channel, allowing independent latch updates without address decoding overhead. Ensure the application can accommodate the 24-pin DIP footprint if surface mount alternatives are not required.

Part Context

The AD7247ABN is part of the enhanced AD7237A/AD7247A family, which improves upon the industry-standard AD7237/AD7247. Enhancements include operation from 12 V supplies, faster interface times with a typical 30 ns data setup time, and improved reference stability with respect to supply voltage variations. It utilizes Linear Compatible CMOS (LC2MOS) technology.

Replacement Considerations

The AD7247AAN serves as a lower accuracy alternative with ±1 LSB relative accuracy. For surface mount requirements, the AD7247AAR offers the same electrical characteristics in a 24-lead SOIC package. The AD7237A provides similar functionality but utilizes an 8-bit double-buffered interface structure instead of parallel loading.