Browse Prior Art Database

Synchronization of Multiple Voltage Regulator Outputs

IP.com Disclosure Number: IPCOM000123874D
Original Publication Date: 1999-Jun-01
Included in the Prior Art Database: 2005-Apr-05
Document File: 2 page(s) / 57K

Publishing Venue

IBM

Related People

Mueller, MW: AUTHOR [+3]

Abstract

In larger computer systems, high voltage DC power distribution is sometimes employed. Here, power distribution is split across multiple DC to DC converters (called Voltage Regulator Modules or VRM's). Often there exists a requirement to change the margins of the voltage output by a small percentage, e.g. to change 5 Volts by +/- 5% on command. This becomes a problem when two or more VRM's are providing power on the same output voltage, i.e. shared power. The problem exists when changing an output to a individual VRM requires a command for each VRM. There is a finite amount of time required to issue this command and since each VRM has independent control, you can not simultaneously change all VRMs on a common voltage.

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Synchronization of Multiple Voltage Regulator Outputs

   In larger computer systems, high voltage DC power
distribution is sometimes employed.  Here, power distribution is
split across multiple DC to DC converters (called Voltage Regulator
Modules or VRM's).  Often there exists a requirement to change the
margins of the voltage output by a small percentage, e.g. to change 5
Volts by  5% on command.  This becomes a problem when two or more
VRM's are providing power on the same output voltage, i.e. shared
power.  The problem exists when changing an output to a individual
VRM requires a command for each VRM.  There is a finite amount of
time required to issue this command and since each VRM has
independent control, you can not simultaneously change all VRMs on a
common voltage.  This results in the first VRM driving all or none of
the power, depending on if it was margined above or below the current
settings of the other VRM's on that voltage.  This results in an
'over current' condition and possibly shutting down the VRM and
system.  This invention allows all the VRM's to adjust their outputs
simultaneously, avoiding the pitfalls mentioned above.

   In a large computer when you have multiple shared outputs
from VRM's, this creates a large number of separate adjustments for
margining.  The communication to the control registers of these VRM's
can be via I2C bus, a low speed serial communications bus.  Due to
the nature of controlling the VRM's and adjusting the o...