AD7845JN

Overview

The AD7845JN is a complete 12-bit multiplying digital-to-analog converter (DAC) with an integrated output amplifier, fabricated on the LC2MOS process. It features full 4-quadrant multiplication capability and includes three on-chip application resistors for gain ranging and offset adjustment. The device utilizes parallel data inputs compatible with TTL and 5 V CMOS logic, controlled by standard CS and WR signals. It operates within a temperature range of 0°C to +70°C and requires dual power supplies of ±14.25 V to ±15.75 V. Key performance metrics include a settling time of 5 µs to 0.01% and guaranteed monotonicity across the operating temperature range.

Feature Summary

• Integrated 12-bit CMOS multiplying DAC with on-chip unity-gain output amplifier
• Full 4-quadrant multiplication with internal application resistors (RA, RB, RC) for gain scaling
• TTL and 5 V CMOS compatible digital inputs with latch control via CS and WR signals
• Guaranteed monotonic operation from -55°C to +125°C (extended versions) or 0°C to +70°C (J version)

Applications

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

Procurement Notes

Verify the specific suffix 'JN' corresponds to the Plastic DIP (N-24) package and the commercial temperature range (0°C to +70°C). Confirm that the ordering guide lists this exact part number for the required accuracy grade (-1 LSB relative accuracy at +25°C). Ensure compatibility with existing PCB footprints for the 24-lead DIP configuration before procurement.

Selection Notes

Select the AD7845JN when a 12-bit resolution with integrated buffering and 4-quadrant multiplying functionality is required in a through-hole DIP package. Choose this variant over surface-mount options if board space allows for larger packages and if the commercial temperature range (0°C to +70°C) meets system requirements. Consider higher-grade versions (e.g., K, A, B) if tighter linearity or extended temperature ranges are necessary.

Part Context

The AD7845JN belongs to the AD7845 family of complete 12-bit CMOS multiplying DACs. This family distinguishes itself by integrating the output amplifier and application resistors directly onto the chip, reducing external component count. The 'J' suffix denotes the commercial temperature grade, while 'N' indicates the 24-lead plastic DIP package. Other variants in the series offer different packages like SOIC or LCC and extended industrial/aerospace temperature ranges.

Replacement Considerations

Direct replacements within the same family include AD7845KN (same package, better accuracy), AD7845JR (SOIC package), and AD7845AR (Industrial temp, SOIC). For hermetic ceramic packages, consider AD7845SQ/883B. Verify pinout compatibility and thermal characteristics when substituting.