AD8804ARUZ

Overview

The AD8804ARUZ is a 12-channel, 8-bit TrimDAC in a TSSOP-20 package. It provides independent digitally controllable voltage outputs with a settling time of 600 ns and a supply current of 10 μA at 5 V. The device operates on a single +3 V to +5 V supply and features a 3-wire SPI compatible serial interface. A key distinction from the AD8802 is the inclusion of a VREFL pin, allowing for an independent zero-scale voltage setting. Power consumption drops below 55 mWatts, including reference current, and the unit maintains latch settings during shutdown.

Feature Summary

• 12 independent 8-bit DAC channels with individually programmable outputs
• Separate VREFL pin enables independent zero-scale voltage setting
• Low power operation: 10 μA supply current and <55 mW total dissipation
• 3-Wire SPI compatible serial interface with power shutdown capability

Applications

• Automatic adjustment and trimmer replacement
• Video and audio equipment gain and offset adjustment
• Portable and battery operated equipment

Procurement Notes

Verify the specific ordering suffix ARUZ corresponds to the TSSOP-20 package option RU-20. Confirm that the VREFL pin functionality is required for the design, as this distinguishes the AD8804 from the AD8802. Ensure ESD precautions are observed during handling due to the sensitivity of the CMOS input structure.

Selection Notes

Select the AD8804 over the AD8802 when a non-zero baseline output voltage is necessary via the external VREFL connection. Verify that the 8-bit resolution and 5 kΩ output impedance meet the system requirements. Ensure the microcontroller interface supports the 12-bit serial word format (4 address bits plus 8 data bits) or utilizes the provided software routines for bit manipulation.

Part Context

The AD8804 is part of the AD8802/AD8804 family of 12-channel TrimDACs designed to replace mechanical potentiometers. While sharing identical channel counts, resolution, and serial interfaces, the AD8804 differentiates itself by providing a dedicated VREFL pin. This allows designers to shift the entire output voltage range, optimizing resolution for applications with limited allowable voltage control ranges.

Replacement Considerations

The AD8802 serves as a direct functional substitute if the application does not require an adjustable zero-scale voltage via VREFL. In such cases, the VREFL pin on the AD8804 can be left unconnected or tied to ground, though the AD8802 simplifies the layout by having VREFL internally connected to GND.