Maxim Integrated Sink/Source Current DACs

Maxim Integrated Products has introduced its DS4422/DS4424 dual-/quad-channel, sink/source current DACs. These I2C-controlled, 7-bit current DACs feature two (DS4422)/four (DS4424) output channels that are specifically designed for power-supply margining and adjustment. Each output channel provides control of a DC-DC power supply by sinking or sourcing current directly into the power supply's feedback node. This control technique allows existing power-supply designs to be margined and adjusted with minimal redesign, thus making the DS4422/DS4424 ideal for servers, video processing cards, and other DC-DC power-supply applications.



The DS4422/DS4424 power-up in a neutral (or zero-current) output condition to minimize system-startup overhead requirements allow the power-supply feedback resistors to perform in a standard manner. These DACs utilize an external resistor to program the full-scale current for each output from 50microamps to 200microamps with ±6% accuracy. The I2C bus can then be used to linearly set the output currents to any of the 127 sink or 127 source steps up to the maximum value. Two address inputs allow up to four devices or sixteen separate supplies to be controlled on a single I2C bus. Fully specified over the -40 degrees Celsius to +85 degrees Celsius extended temperature range, the DS4422/DS4424 are available in a tiny, 3mm x 3mm, 14-pin TDFN package. Prices start at $0.53 for the DS4422 and $0.67 for the DS4424 (10,000-up, FOB USA).