Dual, 10-Bit, Low-Power, 2-Wire, Serial Voltage-Output DAC

The MAX5821 is a dual, 10-bit voltage-output, digital-to-analog converter (DAC) with an I²C-compatible, 2-wire interface that operates at clock rates up to 400kHz. The device operates from a single 2.7V to 5.5V supply 115µA at VDD = 3.6V. A power-down mode decreases current consumption to less than 1µA. The MAX5821 features three software-selectable power-down output impedances: 100kΩ, 1kΩ, and high impedance. Other features include internal precision Rail-to-Rail output buffers and a power-on reset (POR) circuit that powers up the DAC in the 100kΩ power-down mode.

The MAX5821 features a double-buffered I²C-compatible serial interface that allows multiple devices to share a single bus. All logic inputs are CMOS-logic compatible and buffered with Schmitt triggers, allowing direct interfacing to optocoupled and transformer-isolated interfaces. The MAX5821 minimizes digital noise feedthrough by disconnecting the clock (SCL) signal from the rest of the device when an address mismatch is detected. The MAX5821 is specified over the extended temperature range of -40°C to +85°C and is available in a miniature 8-pin µMAX® package. Refer to the MAX5822 data sheet for the 12-bit version.

Applications

* Battery-Powered Applications * Digital Gain and Offset Control * Low-Cost Instrumentation * Programmable Attenuators * Programmable Voltage and Current Sources * VCO/Varactor Diode Control

* Ultra-Low Supply Current

* 115µA at VDD = 3.6V

* 135µA at VDD = 5.5V

* 300nA Low-Power Power-Down Mode

* Single 2.7V to 5.5V Supply Voltage

* Fast 400kHz I²C-Compatible 2-Wire Serial Interface

* Schmitt-Trigger Inputs for Direct Interfacing to Optocouplers

* Rail-to-Rail Output Buffer Amplifiers

* Three Software-Selectable Power-Down Output Impedances

* 100kΩ, 1kΩ, and High Impedance

* Read-Back Mode for Bus and Data Checking

* Power-On Reset to Zero

* 8-Pin µMAX Package