THREE-PIN MOS TYPE RINGER

摘要

The 3-pin MOS-type ringer includes a voltage controlling circuit for controlling a standby voltage level, a voltage hysterisis range signal generating circuit for supplying the standby voltage level and N-bias voltage to the voltage controlling circuit, an oscillation circuit for receiving an enable signal output from the voltage hysterisis range signal generating circuit, a frequency demultiplier for frequency-demultiplying the oscillation frequency output from the oscillation circuit, and a counter for receiving the frequency signal and enable signal and generating a ring output, thereby realizing the 3-pin MOS-type ringer in which there is no tapping and an external circuit is simplified.