AD7247AAN

Overview

The AD7247AAN 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 voltage reference and output amplifiers within an LC2MOS process. The device features a parallel loading structure with separate Chip Select inputs for each DAC and a common Write input. It supports single or dual supply operation, typically ranging from +12 V to +15 V for VDD and 0 V or -12 V to -15 V for VSS. Key electrical parameters include a maximum relative accuracy of ±1 LSB, a typical settling time of 5 µs, and a power dissipation of approximately 165 mW in single-supply mode.

Feature Summary

• Dual 12-bit DAC architecture with integrated 5 V Zener reference and buffered output amplifiers
• Parallel interface with independent Chip Select (CSA/CSB) and common Write (WR) inputs
• Configurable output ranges: 0 V to +5 V, 0 V to +10 V (unipolar), and ±5 V (bipolar)
• Industrial temperature range (-40 °C to +85 °C) with ±1 LSB maximum relative accuracy

Applications

• Microprocessor-based data acquisition systems requiring direct 12-bit parallel interfacing
• Programmable gain amplifier control circuits
• Waveform generation and signal synthesis applications
• Calibration voltage sources for test and measurement equipment

Procurement Notes

Verify the specific suffix 'AN' corresponds to the plastic DIP-24 package and industrial temperature range (-40 °C to +85 °C). Confirm that the required relative accuracy of ±1 LSB meets system specifications, as higher precision variants (e.g., ABN) offer ±1/2 LSB. Ensure ESD precautions are observed during handling due to the sensitivity of the CMOS internal circuitry.

Selection Notes

Select the AD7247AAN when a parallel interface with independent channel selection is preferred over the double-buffered serial-style interface of the AD7237A. This model is suitable for systems operating with standard +12 V to +15 V supplies. If bipolar output capability is not required, single-supply operation simplifies power design. Verify that the 5 µs typical settling time and 165 mW power consumption align with the thermal and speed constraints of the target application.

Part Context

The AD7247A is an enhanced version of the industry-standard AD7247, offering improved interface speeds (30 ns typical data setup time) and better reference stability with respect to VDD variations. It belongs to the DACPORT family, which combines precision analog circuits with low-power CMOS logic. The 'AN' designation specifically identifies the non-hermetic plastic dual-in-line package variant intended for general industrial use.

Replacement Considerations

The AD7247ABN offers the same package and interface but with improved ±1/2 LSB accuracy. The AD7247ATQ provides extended temperature range (-55 °C to +125 °C) and ±1/2 LSB accuracy in a ceramic package. For systems requiring an 8-bit bus interface, the AD7237AAN is the functional counterpart with a double-buffered input structure.