PMBus
PMBus (Power Management Bus) is an open, I2C-based protocol used to monitor and control power-management devices such as DC-DC converters, voltage regulators, power supplies, and battery chargers. It provides a common command set and data formats that enable vendors to report measurements and to configure operating parameters from a central controller. PMBus is designed to work over the SMBus/I2C electrical layers and to support multiple devices on a shared two-wire bus, with an alert mechanism for asynchronous fault signaling. The specification defines standard commands for measuring and reporting voltages, currents, power, temperatures, and fan speeds, as well as control functions for regulation modes, output voltage setpoints, and fault handling. It also supports data formatting options (linear data formats with signed/unsigned values) and both read and write operations, including block read/write and manufacturer-specific (MFR) commands. An alert/status model allows devices to signal faults to a central controller, often via a designated ALERT line and an alert response protocol.
PMBus is maintained by the PMBus Association and is widely adopted in power-management applications across data