Title: Semiconductor integrated circuit and radio communication apparatus for communication
Application Number: 200610077168 Application Date: 2006.04.27
Publication Number: 1862979 Publication Date: 2006.11.15
Approval Pub. Date: Granted Pub. Date:
International Classifi-cation: H04B1/40,H04L27/18,H03L7/00
Applicant(s) Name: Renesas Tech Corp. Address:
Inventor(s) Name: Okazaki Takao
Attorney & Agent: wang yang
Abstract:
     A total power consumption of a radio communication apparatus is reduced, the radio communication apparatus including a semiconductor integrated circuit (high-frequency IC) which has a clock generation circuit which generates a reference clock signal for use in modulating a transmit signal and demodulating a received signal. The clock generation circuit is provided with a voltage-controlled oscillator circuit (VCXO) which oscillates, when a quartz oscillator is connected thereto, at a frequency dependent on a natural frequency of the quartz oscillator and a control voltage applied thereto. The voltage-controlled oscillator circuit is configured such that a result obtained by converting, in an internal DA converter circuit, digital frequency control information supplied from the baseband circuit is applied as the control voltage to the voltage-controlled oscillator circuit and such that the voltage-controlled oscillator circuit oscillates at a frequency corresponding to the control voltage.
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