AD7847AQ

Overview

The AD7847AQ is a dual 12-bit multiplying digital-to-analog converter (MDAC) manufactured by Analog Devices. It features an R-2R resistor ladder architecture with integrated output amplifiers, providing voltage outputs. The device operates on ±15 V power supplies and supports a parallel interface with separate chip selects for each channel. Key static performance metrics include a relative accuracy of ±1 LSB and a settling time of 3 µs to within ±1/2 LSB. The unit is housed in a 24-lead Cerdip package and functions within a temperature range of -40°C to +85°C.

Feature Summary

• Dual 12-bit resolution with internal R-2R ladder structure
• Integrated buffered voltage outputs with 3 µs settling time
• Parallel interface with independent CSA and CSB chip selects
• Multiplying capability allowing AC or DC reference inputs

Applications

• Programmable gain amplifier circuits
• Four-quadrant analog multiplication
• Analog panning systems for audio applications

Procurement Notes

Verify the Q-24 Cerdip package designation and the specific A version accuracy rating of ±1 LSB during sourcing. Confirm that the operating environment remains within the specified -40°C to +85°C industrial temperature range. Ensure proper ESD handling procedures are followed due to the sensitivity of the CMOS input circuitry.

Selection Notes

Select the AD7847AQ when independent chip select control for each DAC channel is required, distinguishing it from the AD7837 which uses address lines. This model is suitable for designs requiring ±1 LSB linearity accuracy. Verify that the system can accommodate the required ±15 V supply rails and that the parallel data bus timing meets the 30 ns minimum write pulse width specification.

Part Context

This component belongs to the AD7837/AD7847 family of high-speed multiplying DACs. The AD7847 variant is distinguished by its dedicated chip select pins for each channel, facilitating direct memory-mapped interfacing with microprocessors without complex address decoding logic compared to the AD7837.

Replacement Considerations

The AD7847ANZ serves as a pin-compatible alternative in a Plastic DIP package. The AD7847ARZ offers the same electrical specifications in a SOIC package. Both variants maintain the dual-channel 12-bit architecture but differ in physical footprint and mounting style.