Title:
PORTABLE DEVICE
Document Type and Number:
Japanese Patent JP2000354336
Kind Code:
A
Abstract:
To dispense with back-up battery.
Normally, a CPU 130 monitors the voltage of secondary battery 200, and if the remaining capacity of the secondary battery 200 decreases to a value that is required for backing up a real-time clock(RTC) 110, shift is made for an operation mode to a standby mode. At this time, a DC-DC converter 140 is also shifted to the standby mode. At shifting to the standby mode, the DC-DC converter generates a back-up power by the secondary battery 200 to supply power to the CPU 130 and RTC 110, which turns into the standby mode consuming less power. The RTC 110 continues timer counting by the back-up power supplied.
Inventors:
HOSOGAYA NORIBUMI
Application Number:
JP16004899A
Publication Date:
December 19, 2000
Filing Date:
June 07, 1999
Export Citation:
Assignee:
SONY CORP
International Classes:
G06F1/26; G06F1/30; H02J7/34; H02J9/06; (IPC1-7): H02J7/34; G06F1/26; G06F1/30; H02J9/06