Analog Devices Inc. AD8804AR

Overview

AD8804AR from Analog Devices is a 12-channel, 8-bit voltage-output digital-to-analog converter (DAC) with independent zero- and full-scale reference inputs (VREFL and VREFH), 3-wire SPI-compatible serial interface, ±1/2 LSB typical integral nonlinearity, and shutdown current of ≤10 µA. It replaces mechanical trimmers in precision DC voltage adjustment circuits for video, graphics, and portable equipment.

For engineers reviewing the AD8804AR datasheet, AD8804AR pinout, AD8804AR application, or AD8804AR equivalent, this page delivers verified technical context, real-world design meaning of key specs, validated package and pin mapping, confirmed alternative options, and supply-chain support details specific to the AD8804AR variant.

Technical Context

The AD8804AR implements twelve independent R-2R ladder DACs sharing common VREFH and VREFL reference inputs, enabling programmable output ranges via VO(Dx) = (Dx/256) × (VREFH – VREFL) + VREFL. Each DAC features its own latch updated from a 12-bit serial shift register (4-bit address + 8-bit data), with positive-edge clocking and active-low chip select decoding.

It supports single-supply operation from 2.7 V to 5.5 V, consumes ≤10 µA supply current in normal mode, and reduces reference input current to ≤10 µA in shutdown while preserving DAC latch states. Output resistance is 5 kΩ ±20% per channel, with <1.5% match between channels and 500 ppm/°C temperature coefficient.

Key Specifications

Pinout & Package

AD8804AR is packaged in a 20-lead SOIC (SOL-20, package option R-20), with 1.27 mm pitch, body width 7.5 mm, and JEDEC MS-013AC compliance.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar 12-channel DAC applications.

Compared with AD8802AR and MCP4822-E/P, the AD8804AR uniquely supports independent VREFH/VREFL programming for arbitrary output spans-enabling optimal utilization of limited voltage headroom in portable and mixed-signal systems where zero-scale offset is critical.

Availability

AD8804AR is available at Aetrix Electronics and suitable for video calibration, CRT geometric correction, portable instrumentation trimming, battery-powered audio balancing, and industrial sensor front-end biasing requiring stable component supply across extended temperature ranges (–40°C to +85°C).

Supply support for AD8804AR includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

Analog Devices, Inc. is a global leader in high-performance analog, mixed-signal, and digital signal processing semiconductors, founded in 1965 and headquartered in Wilmington, MA.

The AD8804AR belongs to Analog Devices' TrimDAC® family-designed specifically to replace mechanical potentiometers in precision DC voltage adjustment applications where programmability, stability, and space savings are essential.

FAQ

What is the function of the VREFL pin on the AD8804AR?

The VREFL pin on the AD8804AR sets the zero-scale voltage for all 12 DAC outputs and is exclusive to the AD8804 family (not present on AD8802). It accepts any voltage from 0 V to VDD, allowing user-defined output ranges such as 0.2 V to 4.8 V. When VREFL is set above GND, the DAC ladder sinks current from VREFL, enabling true bipolar or offset-adjustable unipolar operation. This functionality is absent in AD8802AR, which ties VREFL internally to GND.

Does the AD8804AR require external op-amps to drive standard loads?

The AD8804AR has a nominal output resistance of 5 kΩ, making it suitable for driving high-impedance nodes like op-amp inputs or microcontroller ADC references directly. However, for low-impedance loads (<10 kΩ) or applications demanding fast settling or rail-to-rail swing beyond its native range, an external op-amp buffer (e.g., OP291 or OP193) is recommended-as documented in Analog Devices' application notes for the AD8804AR. The device does not include internal output amplification.

How does the AD8804AR handle power-down sequencing?

When SHDN is asserted high, the AD8804AR disables reference current draw (≤10 µA), opens all 12 DAC outputs, and places internal circuitry in zero-power state-but retains all DAC latch register contents. Upon returning SHDN to low, outputs resume their pre-shutdown voltages without reprogramming. This behavior is explicitly guaranteed in the AD8804AR datasheet and differs from parts requiring full register reload after wake-up.

Can the AD8804AR be used with 3 V microcontrollers while powered from 5 V?

Yes-the AD8804AR supports mixed-voltage interfacing: its digital inputs (CS, CLK, SDI) tolerate voltages up to 8 V and are fully compatible with 3 V logic levels even when VDD = 5 V. VIH(min) is 2.1 V at VDD = 3 V and 2.4 V at VDD = 5 V, ensuring reliable recognition of 3 V logic highs. This allows direct connection to 3 V MCUs without level shifters, as confirmed in the AD8804AR Absolute Maximum Ratings and Digital Inputs specifications.

What is the maximum clock frequency supported by the AD8804AR serial interface?

The AD8804AR supports a maximum serial clock (CLK) frequency of 33 MHz, as stated in its operational description and timing diagrams. Minimum clock pulse width is 15 ns (high or low), corresponding to a 33.3 MHz theoretical limit. At this rate, loading a single DAC takes 12 clock cycles (~360 ns), and updating all 12 channels requires ≤4.6 µs-enabling real-time recalibration in high-speed test equipment and adaptive display systems using the AD8804AR.