Sink/source current DACs

Maxim has introduced the DS4422/DS4424 low-cost, dual-/quad-channel, sink/source current DACs.

These 1²C-controlled 7-bit current devices 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 allows existing power supply designs to be margined and adjusted with minimal redesign, making the DS4422/DS4424 suitable for servers, video processing cards and other DC-DC power supply applications.

The devices power-up in a neutral (or zero-current) output condition to minimise system-startup overhead requirements and allow the power supply feedback resistors to perform in a standard manner.

To maximise versatility, the DACs use an external resistor to program the full-scale current for each output from 50 to 200 µA with ±6% accuracy. The 1²C 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 16 separate supplies to be controlled on a single 1²C bus.