AD7247ATQ

Overview

The AD7247ATQ is a dual 12-bit voltage-output digital-to-analog converter (DAC) from the AD7237A/AD7247A family, manufactured by Analog Devices. It integrates two CMOS DACs with on-chip output amplifiers and a Zener voltage reference on a single monolithic LC2MOS chip. The device features a parallel loading structure for direct microprocessor interfacing. It supports operation from +12 V to +15 V supplies with optional negative supply rails of 0 V or -12 V to -15 V. Key electrical parameters include a maximum settling time of 10 µs, a typical power dissipation of 165 mW in single-supply mode, and an extended temperature range of -55°C to +125°C.

Feature Summary

• Dual 12-bit resolution with integrated output amplifiers and internal 5 V reference.
• Parallel interface with separate Chip Select inputs for each DAC channel.
• Extended industrial temperature range (-55°C to +125°C) for the ATQ variant.
• Configurable unipolar (0-5V, 0-10V) and bipolar (+/-5V) output ranges via ROFS pins.

Applications

• Industrial process control systems requiring precise analog signal generation.
• Direct interfacing with 8-bit and 16-bit microprocessors such as Intel 8086 or Motorola 68000.
• Multi-channel data acquisition systems utilizing simultaneous or independent DAC updates.

Procurement Notes

Verify the specific suffix 'TQ' indicates the ceramic DIP package and extended temperature rating. Confirm RoHS compliance status as older manufacturing runs may vary. Check for discontinuation notices or lifecycle status through official Analog Devices channels prior to procurement planning.

Selection Notes

Select the AD7247ATQ over the AD7237ATQ when a simple parallel 12-bit latch interface is preferred over the double-buffered 8-bit bus structure. Ensure the application requires the extended -55°C to +125°C operating range provided by the 'T' grade. Verify that the 24-pin CDIP package fits the target PCB layout constraints.

Part Context

The AD7247ATQ is part of the enhanced AD7237A/AD7247A series, which improves upon the original industry-standard AD7237/AD7247 parts. These enhancements include faster interface times, improved reference variations with supply voltage, and wider power supply operation ranges. The 'T' designation specifies the military-grade temperature range, while 'Q' denotes the hermetic ceramic dual-in-line package.

Replacement Considerations

The AD7247ABR serves as a lower-temperature alternative if the extended range is not required. For applications needing an 8-bit bus interface, the AD7237ATQ is the functional equivalent within the same package and temperature grade.

FAQ

How is the output voltage range configured?

The output range is set by connecting the ROFS pin: to VOUT for 0-5V, to GND for 0-10V, or to REF IN for ±5V bipolar operation.

What is the maximum settling time specified?

The maximum settling time to within ±1/2 LSB is 10 µs for both positive and negative full-scale changes.

Can the internal reference be used externally?

Yes, the REF OUT pin provides the internal 5 V reference, capable of sourcing up to 500 µA to external loads.