AD7845TQ

Overview

The AD7845TQ is a complete 12-bit CMOS multiplying digital-to-analog converter (MDAC) featuring an integrated output amplifier. Fabricated on the LC2MOS process, it supports full 4-quadrant multiplication with TTL and 5 V CMOS compatible digital inputs. The device operates within an extended temperature range of –55°C to +125°C. Key electrical specifications include a maximum settling time of 5 µs to 0.01% of full-scale range, a typical glitch impulse of 5 nV-s, and a unity gain small signal bandwidth of 600 kHz. It utilizes a parallel data interface controlled by CS and WR signals.

Feature Summary

• Integrated output amplifier providing 4-quadrant multiplying capability
• On-chip application resistors (RA, RB, RC) for gain ranging and offset adjustment
• Extended industrial temperature range (-55°C to +125°C)
• Guaranteed monotonic operation across the full temperature range

Applications

• Automatic Test Equipment
• Programmable Power Supplies
• Digital Attenuators
• Programmable Gain Amplifiers
• Digital-to-4–20 mA Converters

Procurement Notes

Verify the specific suffix 'TQ' against the manufacturer's ordering guide to confirm package type and temperature grade. The datasheet lists the T version as operating from -55°C to +125°C in a Q-24 Cerdip package. Confirm that the /883B military processing option is not required unless specified, as standard commercial versions are distinct from hermetic MIL-STD-883B variants.

Selection Notes

Select the AD7845TQ when extended temperature performance (-55°C to +125°C) is required alongside 12-bit resolution. Ensure the system design accommodates the ±14.25 V to ±15.75 V power supply range. Verify that the parallel interface timing requirements (tCS min 30 ns, tWR min 30 ns) align with the microprocessor or controller driving the device.

Part Context

The AD7845 series represents Analog Devices' first 4-quadrant multiplying DAC with an on-chip amplifier. The T variant specifically denotes the extended temperature grade housed in a Q-24 Cerdip package. This component belongs to a family that includes J, K, A, B, and S grades, differentiated primarily by operating temperature ranges and relative accuracy specifications.

Replacement Considerations

Public confirmed substitute part numbers: None.