Telecommunications – Receiver or analog modulated signal frequency converter – Local control of receiver operation
Reexamination Certificate
2006-12-05
2006-12-05
Milord, Marceau (Department: 2618)
Telecommunications
Receiver or analog modulated signal frequency converter
Local control of receiver operation
C455S084000, C455S260000, C455S126000, C455S180300, C455S190100, C455S264000, C455S265000, C331S016000, C331S025000, C375S327000, C375S344000
Reexamination Certificate
active
07146143
ABSTRACT:
The invention provides a communication semiconductor integrated circuit device (RF IC) capable of pulling in the frequency of a PLL circuit to a desired set frequency at high speed even in the case where a frequency settable range of the PLL circuit is wide without providing a current source other than a current source for charging and discharging in an normal operation. An oscillator as a component of a PLL circuit is constructed so as to be operative in a plurality of bands. In a state where a control voltage of the oscillator is fixed to a predetermined value, an oscillation frequency of the oscillator is measured in each of bands and stored in a storing circuit. A set value for designating a band supplied at the time of PLL operation is compared with the stored measured frequency value. From a result of comparison, a band to be actually used in the oscillator is determined, and a frequency difference between the maximum frequency of the selected band and the set frequency is obtained. Further, a control voltage closest to the set frequency is determined on the basis of the frequency difference and the frequency variable range of the selected band and the control voltage is applied to the oscillator to start oscillating operation. After that, a PLL loop is closed and locked.
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patent: 02/05152 (2002-11-01), None
Kasahara Masumi
Kurakami Noriyuki
Oosawa Hirotaka
Uozumi Toshiya
Milord Marceau
Renesas Technology Corp.
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