AD8842AR

Overview

The AD8842AR is an 8-bit, 8-channel, 4-quadrant multiplying CMOS TrimDAC in a 24-lead SOIC_W package. It provides digitally controlled voltage adjustment to replace mechanical trimmers. Each channel features a current conveyor amplifier for constant input resistance and four-quadrant multiplication. The device operates from ±5 V supplies, delivering ±3 V output swings with a 50 kHz full-power bandwidth. It utilizes a 3-wire serial interface (CLK, SDI, LD) with daisy-chain capability via SDO. Key static accuracy metrics include ±1 LSB INL, ±1 LSB DNL, and a typical zero output error of 5 mV.

Feature Summary

• Eight independent 4-quadrant multiplying channels with 50 kHz bandwidth
• Current conveyor amplifier design ensures constant input resistance
• 3-wire serial interface supports daisy-chaining multiple devices
• Asynchronous preset pin 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 the specific ordering suffix against the manufacturer's guide. The 'AR' suffix denotes the 24-lead SOIC_W package option. The 'Z' suffix indicates RoHS compliance. Ensure the required temperature range (-40°C to +85°C) matches the application environment. Confirm power supply requirements align with the specified ±5 V operation for optimal performance.

Selection Notes

Select the AD8842AR when eight independent analog signal adjustments are required in a compact surface-mount package. It is suitable for applications needing 4-quadrant multiplication for signal inversion or modulation up to 50 kHz. Compare against the DAC8840 if higher bandwidth (1 MHz) is necessary, as they are pin-compatible. Ensure the system can provide the required ±5 V dual supplies for the specified ±3 V output swing.

Part Context

The AD8842 is part of Analog Devices' TrimDAC family, designed to replace mechanical potentiometers. It is pin-compatible with the DAC8840, which offers a higher 1 MHz multiplying bandwidth. The device integrates eight separate DAC registers updated via a serial-to-parallel shift register, allowing individual channel control without disturbing other outputs.

Replacement Considerations

The DAC8840 is a confirmed pin-compatible substitute offering increased bandwidth. Verify that the target application does not require bandwidth exceeding 50 kHz before selecting the AD8842AR over the DAC8840.