AD8842AN

Overview

The AD8842AN is an 8-bit, octal, 4-quadrant multiplying CMOS TrimDAC featuring eight independent channels. It utilizes a current conveyor amplifier to perform four-quadrant multiplication with constant input resistance, eliminating the need for external buffer amplifiers. The device accepts a 3-wire serial interface (CLK, SDI, LD) with a 12-bit data word comprising a 4-bit address and 8-bit data. Operating from ±5 V supplies, it provides ±3 V output swing and supports a 50 kHz full power gain bandwidth. Key static accuracy parameters include ±1 LSB integral nonlinearity error and a typical output offset of 5 mV.

Feature Summary

• Eight independent 8-bit DAC channels with individual voltage inputs
• 4-quadrant multiplying capability using a single current conveyor amplifier
• 3-wire serial interface with daisy-chain support via SDO pin
• Asynchronous preset function forces all outputs to zero volts

Applications

• Automatic adjustment systems
• Trimmer replacement in circuit designs
• Vertical deflection amplitude adjustment
• Waveform generation and modulation

Procurement Notes

Verify package type upon ordering; the 'AN' suffix denotes a 24-lead plastic DIP (N-24-1). Confirm RoHS compliance requirements, as 'ANZ' indicates a compliant variant. Ensure supply voltages match the specified ±5 V range for optimal performance within the -40°C to +85°C operating temperature window.

Selection Notes

Select the AD8842AN for applications requiring multiple independent analog signal adjustments without mechanical potentiometers. It is suitable for AC or DC gain control up to 50 kHz. For single-supply 5 V applications, consider the pin-compatible DAC-8841 instead. Verify that the load impedance allows for the specified ±3 mA output drive current.

Part Context

The AD8842 is part of Analog Devices' TrimDAC family, designed to replace mechanical trimmers. It is pin-compatible with the DAC8840, which offers a higher 1 MHz multiplying bandwidth. The device integrates digital logic for serial decoding directly onto the silicon, simplifying microprocessor interfacing.

Replacement Considerations

The DAC8840 is a confirmed pin-compatible substitute offering increased bandwidth. Single-supply variants such as the DAC-8841 serve as functional alternatives for 5 V only systems.