Browse Prior Art Database

Maximum Power Management

IP.com Disclosure Number: IPCOM000123277D
Original Publication Date: 1998-Aug-01
Included in the Prior Art Database: 2005-Apr-04
Document File: 2 page(s) / 40K

Publishing Venue

IBM

Related People

Odaohara, S: AUTHOR [+2]

Abstract

Disclosed is a circuit to manage maximum power of system. In general, higher performance of central processing unit requires larger power. In worst case, power of AC adapter may not be enough when the system is running with maximum performance. This circuit provides method to manage maximum power by backing up power using another power source when power of AC adapter (or power supply unit) is not enough.

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Maximum Power Management

   Disclosed is a circuit to manage maximum power of
system.  In general, higher performance of central processing unit
requires larger power.  In worst case, power of AC adapter may not be
enough when the system is running with maximum performance.  This
circuit provides method to manage maximum power by backing up power
using another power source when power of AC adapter (or power supply
unit) is not enough.

   The figure shows a power path control circuit of
system.  There is a step-up converter to back up power of AC
adapter.  In this sample, source power  of the step-up converter is a
battery which is installed in the system.  The output voltage of
step-up converter is Vbup.  Vbup is set to a voltage which is a
little bit lower than Vacdc, that is the voltage of AC adapter.  That
is, Vbup is lower than Vacdc.  In case the system is in normal
operation and the system performance is not maximum, voltage of Vint
will be Vacdc  since the power of AC adapter is enough for the
system.  The step-up converter does not supply power to the system in
this case.  In case the system is running full operation and AC
adapter cannot supply enough power to the system, the output voltage
of AC adapter goes down to Vbup and the step-up converter starts
supplying power to the system at the same time.  The step-up
converter backs up power that the AC adapter is lacking.  Thus, this
circuit provides method to manage maximum power when power of AC
a...