The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Aug. 10, 2004
Filed:
Nov. 07, 2002
Renesas Technology Corp., Tokyo, JP;
Abstract
The present invention provides a power supply circuit, which supplies a power supply voltage to a high frequency power amplifier. The power supply circuit comprises a DC—DC converter, a voltage control transistor, and a control circuit which controls the voltage control transistor. When the power supply circuit is used in a CDMA-system cellular phone, the power supply circuit supplies a power supply voltage generated by the DC—DC converter to the high frequency power amplifier upon a low output, whereas upon a high output, the power supply circuit turns on the voltage control transistor to directly supply a battery voltage to the high frequency power amplifier. On the other hand, when the power supply circuit is used in a CGS-system cellular phone, the power supply circuit supplies a power supply voltage generated by the DC—DC converter to the high frequency power amplifier, whereas upon a high output, the voltage control transistor is controlled by the control circuit based on a signal for designating an output level to generate a power supply voltage supplied to the high frequency power amplifier.