Most of you know that the Power Management Bus (PMBus) is an open
standard power-management protocol with a command language that facilitates communication with power converters and other devices in a power system. The protocol is implemented over the industry-standard SMBus serial interface and enables programming, control, and real-time monitoring of compliant power conversion products. And like most standards it changes as the need for refinements are needed.
PMBus V1.3 will be published in Q1 of 2014. The key changes made between PMBus 1.2 and the proposed PMBus 1.3 have been reviewed before, but they can summarized as follows:
* 1 MHz bus speed vs. 400 kHz limit for PMBus 1.2.
* Floating point data format: supports NaN and +/-Inf, 16 bit number, IEEE 754 half precision and it allows easy conversion to C types.
* Relative voltage thresholds: allows programming all output voltage related values thresholds as a percentage of the output voltage.
* Global process call: enables intelligent global queries (extension of the SMBus ARA).
* Adaptive voltage scaling (AVS): dedicated bus to statically and dynamically control processor voltages.
Details available at www.PMBus.org
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