| 摘要 |
PROBLEM TO BE SOLVED: To secure a sufficient dynamic range in accordance with an operation frequency with a simple constitution by changing the resistance value of a collector resistor connected to the collector terminals of dual differential amplifying circuits. SOLUTION: The connection of differential Tr of two differential amplifying circuits is changed and consequently a master/slave-type flip flop circuit is obtained. An input signal from a first input terminal 33 is frequency-divided. A first collector resistor switch means 311 is equivalent to a collector resistor change means and the resistance value can be change with an amplitude control signal inputted from a VR terminal. That is, a resistance element 371 whose one end is connected to the VR terminal, a resistance element 381 whose one end is connected to a power source VCC and a resistance element 391 whose one end is connected to the collector terminals of Tr301 and 302 are installed. The resistance values of first collector resistance switch means 312 and 411 and a second collector resistor switch means 412 can similarly be changed by an amplitude control signal inputted from the VR terminal. |
