| 摘要 |
A prescaler and a buffer are provided to obtain a broadband by uniformizing an input sensitivity characteristic at low and high frequency bands by changing values of resistance and driving ability. A prescaler includes a buffer unit(41), a regulator(42) as a voltage generating circuit, and a counter(43) as a dividing unit. The buffer unit(41) is connected to the other end of a condenser(C1) to which an output signal(fv) is supplied. The buffer unit(41) is coupled with an external circuit and a VOC(Voltage Controlling Oscillator) by the condenser(C1). The regulator(42) decreases an on-resistance value of both transistors(T1,T2) when an inverter circuit(52a) with high driving ability is selected based on a control signal(S2) and generates both voltages(V1,V2) to increase the on-resistance value of both transistors(T1,T2) when an inverter circuit(52c) with low driving ability is selected. Input and output signals of a final stage inverter circuit(54d) of the buffer unit(41) are inputted to the counter(43).
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