AD8802ARUZ

Overview

The AD8802ARUZ is a 12-channel, 8-bit TrimDAC with power shutdown in a 20-lead TSSOP package. It provides independent digitally controllable voltage outputs replacing mechanical trimmers. The device features a 3-wire SPI compatible serial interface and operates on a single +3 V to +5 V supply. Static accuracy includes ±0.25 LSB DNL and ±0.5 LSB INL. Settling time is 600 ns. Power consumption is under 55 mW including reference current. The AD8802 utilizes a midscale preset for initial settings.

Feature Summary

• 12 independent 8-bit DAC channels in a compact 20-lead TSSOP package
• 3-Wire SPI compatible serial input with individually programmable outputs
• Power shutdown mode reduces current to <10 μA while maintaining latch settings
• Midscale preset function via RS pin for simplified initial power-up conditions

Applications

• Automatic adjustment and trimmer replacement in electronic circuits
• Gain and offset adjustment for video and audio equipment
• Geometric correction and automatic adjustment in CRT computer graphic displays

Procurement Notes

Verify component authenticity through authorized Analog Devices distributors or certified secondary market suppliers. Confirm the presence of ESD protection markings and inspect the TSSOP-20 package integrity. Ensure the specific ARUZ suffix corresponds to the required temperature range and packaging format before integration into production lines.

Selection Notes

Select the AD8802ARUZ when twelve independent digital-to-analog conversions are required within a limited board space. This model is suitable for designs needing a midscale preset feature to simplify initialization. Verify that the external reference voltage requirements align with the single-supply operation range of +3 V to +5 V.

Part Context

The AD8802 belongs to the AD8802/AD8804 family of TrimDACs. While the AD8804 offers separate VREFH and VREFL pins for zero-scale setting, the AD8802 fixes VREFL internally to ground. Both share identical serial interfaces, channel counts, and dynamic performance specifications.

Replacement Considerations

Direct pin-compatible replacements include other ADI TrimDACs such as the AD8801 (8-channel) or AD8804 (dual reference). Verify channel count and reference pin configurations match the existing schematic design before substitution.

FAQ

How does the AD8802 handle initial output states upon power-up?

The AD8802 features an asynchronous preset function activated by the RS pin, which loads all DAC registers with a midscale value (80H) to establish a nominal starting voltage.

What is the behavior of the DAC outputs during power shutdown?

In shutdown mode, the DAC structure enters a zero-power state where outputs are open-circuited. The internal DAC latch settings are maintained and restored to their previous voltages upon returning to normal operation.

Can the AD8802 interface directly with 5V logic if operating at 3V?

Yes, digital inputs are protected with series resistors and Zener structures, allowing them to accept logic levels exceeding the VDD supply. This enables direct interfacing with 5V logic even when the part operates at 3V.