PMBus® Specifications

Revision 1.3 of the PMBus specification introduced the enhanced version of PMBus with AVS.
 

PMBus 1.3 includes:

• Higher speed communication to reduce latencies
• A dedicated Adaptive Voltage Scaling (AVS) bus to statically and dynamically control processor voltages
• General enhancements and improvements from 1.2

 
PMBus 1.3.1 includes:

• clarifications to streamline implementation

 
PMBus adopters in good standing can download the latest released PMBus 1.3.1 specification by logging in and going to the home page.
 

All others can get the specification by emailing getpmbusspec@smiforum.org.

• Be sure to include your request, your full name, and your company name in text in English in the body of your email.
• Normally, the current PMBus specification will be delivered to you by email before the end of the next business day.
• Note: We may use the email address you supply to contact you regarding PMBus.

 
Older PMBus specifications are publicly available for download on the Older Specifications page.

 
Additional information on PMBus 1.3:

• 2013-09-12 PMBus 1.3 with AVS presentation at Darnell’s Power Forum (DPF) 2013 (22 slides) (.pptx, .pdf)
• 2013-09-04 New PMBus Spec Includes Dedicated AVS Bus by Rich Pell EE Times
• 2014-03-11 PMBus 1.3 with AVS One Pager (.pdf) 
  

SMBus 3.1 Specification

• 2018-03-19 System Management Bus (SMBus) Specification Version 3.1 (.pdf, 736 KB, 85 pages)

 
Older versions of the SMBus specification can be found on the SMBus Specifications page on the SMBus web site.

Specification questions

Technical questions about specifications should be sent to techquestions@smiforum.org.