JAJSH44C April 2011 – March 2019 UCD90120A
The PMBus is a serial interface specifically designed to support power management. It is based on the SMBus interface that is built on the I2C physical specification. The UCD90120A supports revision 1.1 of the PMBus standard. Wherever possible, standard PMBus commands are used to support the function of the device. For unique features of the UCD90120A, MFR_SPECIFIC commands are defined to configure or activate those features. These commands are defined in the UCD90xxx Sequencer and System Health Controller PMBUS Command Reference (SLVU352). The most current UCD90xxx PMBus™ Command Reference can be found within the TI Fusion Digital Power Designer software via the Help Menu (Help, Documentation & Help Center, Sequencers tab, Documentation section).
This document makes frequent mention of the PMBus specification. Specifically, this document is PMBus Power System Management Protocol Specification Part II – Command Language, Revision 1.1, dated 5 February 2007. The specification is published by the Power Management Bus Implementers Forum and is available from www.pmbus.org.
The UCD90120A is PMBus compliant, in accordance with the Compliance section of the PMBus specification. The firmware is also compliant with the SMBus 1.1 specification, including support for the SMBus ALERT function. The hardware can support either 100-kHz or 400-kHz PMBus operation.