AD7945TQ

Overview

The AD7945TQ is a 12-bit multiplying digital-to-analog converter (DAC) from Analog Devices, housed in a 20-lead ceramic dual in-line package (Cerdip). It operates with a single +5 V supply and features a parallel data interface. The device guarantees ±1 LSB relative accuracy and ±0.5 LSB differential nonlinearity over an extended temperature range of –55°C to +125°C. Key electrical parameters include a typical power dissipation of 5 mW, a settling time of 600 ns to 0.01%, and a glitch impulse of 60 nV-s. It serves as a high-reliability replacement for legacy industry-standard DACs in demanding environments.

Feature Summary

• 12-bit resolution with ±1 LSB relative accuracy and ±0.5 LSB DNL
• Extended industrial temperature range: –55°C to +125°C
• Parallel 12-bit data interface with active-low Chip Select and Write inputs
• Low power consumption: typically 5 μA supply current at idle

Applications

• High-reliability battery-powered instrumentation
• Military and aerospace laptop computers
• Upgrades for all 754x series DACs in 5 V designs

Procurement Notes

Verify the specific ordering suffix 'TQ' corresponds to the Cerdip package and T-grade temperature range when sourcing. Confirm that the required voltage supply matches the +5 V nominal specification for Normal Mode operation. Ensure ESD precautions are observed during handling due to the sensitivity of the CMOS input structure.

Selection Notes

Select the AD7945TQ when an extended temperature range down to –55°C is required alongside hermetic packaging. This model is distinct from the B-grade versions which operate from –40°C to +85°C. Choose this part if a parallel interface is preferred over the serial AD7943 or byte-oriented AD7948 within the same family.

Part Context

The AD7945TQ belongs to the AD7943/AD7945/AD7948 family of fast 12-bit multiplying DACs. While the AD7943 uses a serial interface and the AD7948 uses an 8-bit byte interface, the AD7945 utilizes a full 12-bit parallel interface. The 'T' designation indicates the extended temperature grade, and 'Q' denotes the ceramic DIP package.

Replacement Considerations

Publicly confirmed substitutes include other members of the AD794x family such as the AD7943 or AD7948, provided the interface type matches the system design. Legacy replacements include the AD7543, AD7545, and AD7548 series, offering superior speed and lower power consumption.