Revisions announced to PMBus standard

March 17, 2015 // By Graham Prophet
Revision 1.3.1 of the open standard for power control and monitoring aims to enhance simple and efficient communication between various components of the power system.

The System Management Interface Forum (SMIF Inc.) has launched a revision to its PMBus standard. Revision 1.3.1 supersedes revision 1.3 that was released early last year. It includes numerous clarifications to streamline and speed implementation. These clarifications are primarily centred on the ZONE and the Manufacturer Specific commands. The ZONE command structure is updated to allow definition of an “ALL ZONE” and a “NO ZONE” for greater partitioning flexibility. Additionally, in recognition of the need to address greater functionality, more Manufacturer Specific selections are added in the command space as well as to the WRITE_PROTECT command.

Already adopted by over 30 companies including leading names in the power sector, PMBus is an open standard that was first launched in 2005. It enables communication between the various components of a power system including CPUs, power supplies and power converters. The protocol command language supports the digital management of power supplies and aims to provide simple, standard, flexible, extensible and easy programming. These changes to the PMBus standard are supported and reinforced by recent improvements to the SMBus specification which saw the announcement of Version 3.0 in January 2015. This significantly broadened performance capabilities to ensure compatibility with the very latest industry topologies and harmonised the specification with I ²C.