CHIP FOR NONCONTACT READER/WRITER HAVING FUNCTION FOR MANAGING POWER SUPPLY

Title:

CHIP FOR NONCONTACT READER/WRITER HAVING FUNCTION FOR MANAGING POWER SUPPLY

Document Type and Number:

WIPO Patent Application WO/2002/071325

Kind Code:

A1

Abstract:

A semiconductor integrated circuit device which can perform seamless switching between a power supply obtained by rectifying a carrier and an external power supply. The semiconductor integrated circuit device having a noncontact card function and a noncontact reader/writer function, comprises a rectifier (131) for rectifying a received carrier, a serial regulator (132) for obtaining a predetermined voltage from the output voltage of the rectifier (131), and a power supply control circuit (138) for turning on/off the voltage from a battery (160). Upon receiving a reader/writer mode signal or a card mode signal, the power supply control circuit (138) selects the voltage of the battery (160) as a power supply required for the operation of an IC 300 if the voltage from the battery (160) is not lower than the predetermined voltage, otherwise selects the output voltage from the rectifier (131) as the power supply required for the operation of the IC 300. The device is applicable to mobile terminals such as mobile phones.

Inventors:

ARISAWA SHIGERU (JP)
YAMAGATA AKIHIKO (JP)

Application Number:

PCT/JP2002/001945

Publication Date:

September 12, 2002

Filing Date:

March 04, 2002

Export Citation:

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Assignee:

SONY CORP (JP)
ARISAWA SHIGERU (JP)
YAMAGATA AKIHIKO (JP)

International Classes:

G06K19/07; H02J5/00; (IPC1-7): G06K17/00; H02J7/34; H02J17/00

Domestic Patent References:

WO1999041714A1

1999-08-19

Foreign References:

JPH10261053A	1998-09-29
JP2000184587A	2000-06-30
EP0820178A2	1998-01-21
JP2001005920A	2001-01-12
JPH04241085A	1992-08-28
JPH08185497A	1996-07-16
JPH11355367A	1999-12-24
JPH0661993A	1994-03-04

Other References: