DC/DC controller + PMBus products provide flexible digital control

Although power management is critical to the reliable operation of modern electronic systems, the voltage regulator is perhaps the last remaining “blind spot” in today’s digitally managed systems. When it comes to voltage regulators, there are few ways to directly configure or monitor key power system operating parameters. As a result, power designers who want to fully implement digital control must use a mixture of sequencers, microcontrollers, and voltage supervisors to set basic regulator startup and safety functions. Digitally programmable DC/DC converters are available, especially those designed for VRM core power supplies and with VID output voltage control, but these application-specific converters cannot directly communicate important operating parameters, such as real-time current. 

The LTC3880/LTC3880-1 solves the problem of complex power system management by combining a dual-output synchronous step-down DC/DC controller with comprehensive power management functions available through the I2C-based PMBus bus. PMBus can be used to set output voltage, voltage margining, switching frequency, sequencing, and several other operating parameters (see the “PMBus Control” section below).

Figure 1: Dual-output regulator using external power MOSFETs