AD7845JP

Overview

The AD7845JP is a 12-bit CMOS multiplying digital-to-analog converter (MDAC) with an integrated output amplifier, fabricated on the LC2MOS process. It features full 4-quadrant multiplication capability and guaranteed monotonicity across the commercial temperature range of 0°C to +70°C. The device utilizes a segmented architecture where the two most significant bits drive switches A–C, while the remaining ten bits operate an R-2R ladder. Key electrical specifications include a settling time of 5 µs to 0.01% full-scale range, a typical slew rate of 11 V/µs, and a unity gain small-signal bandwidth of 600 kHz. It operates with dual supplies ranging from ±14.25 V to ±15.75 V.

Feature Summary

• Integrated Output Amplifier: Includes an internally compensated op amp capable of sourcing –10 V into a 2 kΩ load, reducing component count.
• On-Chip Application Resistors: Features three matched resistors (RA, RB, RC) for gain ranging and voltage offsetting without external components.
• TTL/CMOS Compatibility: Digital inputs are compatible with TTL, HCMOS, and +5 V CMOS logic levels.
• Monotonic Performance: Guaranteed monotonic operation over the entire operating 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 JP indicates the Plastic Leaded Chip Carrier (PLCC) package variant. Confirm that the required operating temperature range aligns with the commercial grade (0°C to +70°C). Ensure power supply decoupling is implemented near the VDD and VSS pins to maintain stability given the high-speed output amplifier characteristics.

Selection Notes

Select the AD7845JP when a surface-mount PLCC package is preferred over DIP or SOIC options. This model is suitable for applications requiring 4-quadrant multiplication and on-chip gain adjustment resistors. Compare against the AD7845KP if tighter relative accuracy (1/2 LSB max at +25°C) is required within the same temperature range.

Part Context

The AD7845 series represents Analog Devices' first 4-quadrant multiplying DAC with an on-chip amplifier. The 'JP' designation specifically identifies the version housed in a 28-terminal Plastic Leaded Chip Carrier (PLCC) package. This part belongs to the broader AD7845 family which includes various packages such as DIP, SOIC, and hermetic ceramic variants.

Replacement Considerations

AD7845KP offers improved accuracy (1/2 LSB) in the same PLCC package and temperature range. For different packages, consider AD7845JN (DIP) or AD7845JR (SOIC).