Control VOUT of any DC-DC regulator with a serial PMBus interface

Analog Devices announces the Power by Linear LTC7106, a PMBus I2C controlled precision bidirectional current DAC designed to adjust the output voltage of virtually any DC-DC regulator. Through its PMBus compatible interface, the device receives a 7-bit serial code and converts it to a bidirectional (source, sink) output current. When the current is fed into the feedback network of a regulator, its output voltage can be programmed dynamically for load power/performance optimisation or margining in response to serial VID commands. The device's internal power-on reset circuitry keeps the DAC output current at zero until a valid write takes place. Other features include a range bit for easy interfacing to almost any impedance resistor divider and an open-drain output for controlling the Run or Enable pin of the regulator. To prevent abrupt changes in the DAC output current and subsequently the output voltage of the regulator, an internal digital programmable slew rate can be programmed from 500ns/step to 3.5ms/step. Available in a 2mm x 3mm DFN-10 package, the device enables a small and simple solution for a wide range of discrete and modular DC-DC voltage regulators.