SWITCHED PHASE DUAL-MODULUS PRESCALER CIRCUIT HAVING MEANS FOR REDUCING POWER CONSUMPTION

摘要

Double for frequency-modulus prescaler circuit, multiple asynchronous divider connected in series / 2, the divider / two of 2 (10, 12a) inserted between the phase selector unit 11, and the first control signal (S0, S1, S2, C1, C2) to the control unit for supplying to the selector unit as a function of the selected mode, It includes. The control unit comprises: a first master-slave divider received from the four 90-degree phase-shifted signal with respect to each other, and four phase shift of the signal and supplies the selected signal. The selector unit is connected to two second selection branch, and each branch for receiving the first phase shift select signals (F2I, F2Ib) a first selection branch, two of the second phase shift signal for receiving (F2Q, F2Qb) which comprises a selection element (23). A first control signal (S0, S1, S2) of the first, is supplied to the second selection branch being supplied to the selected element, designated division period and selects one of the four phase shifted signals (F2) to the output in the. The selector unit is the second control signal supplied by the control unit to cut off the power supply of one of the selection branches in a period when the selected branch are selected to supply one of the four phase shifted signals at the output of the selector unit comprises switching means (24, 26) is controlled by a (C1, C2).