Pmbus Interface Option; Rfe2500 May Have Optional Power Management Bus Hardware; Addressing (A2, A1, A0 Inputs); Serial Clock - TDK-Lambda RFE2500 serie Bedienungsanleitung

5.1.1

PMBus Interface Option

The communications bus signals are powered by an external 3.3V power source pulled up with a 1.5kΩ resistor.
5.1.2

RFE2500 May Have Optional Power Management Bus Hardware

The PMBUS interface in the RFE2500 (/S option) includes:
Monitoring the Output Voltage, Current and Temperature.
•
• Programming the Output Voltage and Current.
Programming the Maximum allowed output Voltage.
•
• Programming the Supply On/OFF.
Reading and Clearing Faults.
•
• Reading the Manufacturing Related Data (Model Name, Serial No, Manufacturing Date, etc.).
Storing the following conditions at AC Off.
•
- Set Output voltage / Current limit (OCP).
- Max allowed programmable output voltage.
If PMBus is used for voltage/current programming, the reference voltage will not be fixed to 5V but can be variable
(Reference voltage will be used for voltage/current programming).
The PMBUS supports:
• 100 KHz Operation.
Block Read Protocol.
•
• Group Command Protocol.
Direct Data Format for Monitoring and Programming Functions
•
5.1.3

Addressing (A2, A1, A0 Inputs)

Three variable address lines allow up to 8 Supplies to be connected on a single bus.
PMBus uses 7 bit addressing.
There is constant part of address and variable part of address:
Constant part of address consists of 4 Most Significant Bits A6, A5, A4, A3 always equals 0010.
Variable part of address consists of 3 Least Significant bits: A2, A1, and A0.
Value of these three bits have to be assigned by hardware connections of 3 pins of the PS connectors.
The Address lines (A2, A1, and A0) are internally pulled up by resistors to +5V.
The address lines can be left open for ‹1› address or connected to -S for ‹0› address.
So, available Address Space contains 8 possible addresses: from 0010000 to 0010111.
In case more than one unit is connected to PMBus, each unit must be set to its own unique address.
Duplicate addressing is not allowed.
For example: First unit – A0(J2-1), A1(J2-2), A2(J2-3) are not connected
Second unit - A0(J2-1) is connected to -SENSE
Third unit – A1(J2-2) is connected to -SENSE
A2, A1, A0 signals and -SENSE are NOT isolated from the Output Terminals.
5.1.4

Serial Clock

This line is clocked by the Controller which controls the PMBUS. It should be connected to +3.3V
(Referenced to "Signal RTN") via a 1.5kΩ pull-up resistor.
5.1.5

Serial Data

This is a Bi-Directional line which must be connected to +3.3V (referenced to Signal RTN) via a 1.5kΩ pull up resistor.
ATTENTION:
.
ATTENTION:
19
– ADDRESS 0010111;
– ADDRESS 0010110;
– ADDRESS 0010101;