AD8842ARZ

Overview

The AD8842ARZ is an 8-bit, octal, 4-quadrant multiplying CMOS TrimDAC manufactured by Analog Devices Inc. It integrates eight independent digitally controlled voltage adjustment channels within a single package, designed to replace mechanical potentiometers in circuit designs. The device features a 50 kHz full-power bandwidth and supports AC or DC signal gain control up to this frequency limit. Powered by ±5 V supplies, it delivers ±3 V output swings with low zero output error. Each channel utilizes a current conveyor amplifier architecture for four-quadrant multiplication, providing constant input resistance without requiring external buffer amplifiers.

Feature Summary

• Eight individual 8-bit DAC channels with 4-quadrant multiplying capability
• 50 kHz full power gain bandwidth for AC/DC signal adjustment
• 3-wire serial interface (SDI, CLK, LD) with daisy-chain SDO output
• Low zero output error with midscale preset functionality

Applications

• Automatic adjustment systems
• Trimmer replacement in precision circuits
• Vertical deflection amplitude adjustment
• Waveform generation and modulation

Procurement Notes

Verify the specific ordering suffix against the manufacturer's official guide. The 'Z' suffix indicates RoHS compliance. Confirm the package type matches design requirements: 'AN' denotes a 24-lead PDIP, while 'AR' denotes a 24-lead SOIC_W. Ensure supply voltages align with the specified ±5 V requirement for optimal performance.

Selection Notes

Select the AD8842ARZ when replacing multiple mechanical trimmers with digital control is required. The device operates optimally with ±5 V power supplies; consult the DAC-8841 for single 5 V supply applications. The pinout is compatible with the DAC8840, facilitating upgrades where higher bandwidth is not critical. Ensure load conditions remain within the specified capacitive limits to prevent oscillation.

Part Context

The AD8842 belongs to the TrimDAC family of digitally controlled variable resistors. It serves as a direct functional replacement for mechanical potentiometers in applications requiring programmable gain or attenuation. The device is pin-compatible with the DAC8840, allowing for straightforward integration into existing designs that utilize standard multiplying DAC architectures.

Replacement Considerations

The AD8842 is pin-compatible with the DAC8840. For single-supply 5 V operation, the DAC-8841 is the designated alternative.