Ring oscillator and pulse phase difference encoding circuit

摘要

A ring oscillator for circulating pulse edges of two types therein includes an even number of inverting circuits connected in a ring. Each of the inverting circuits is operative to invert an input signal and output an inversion of the input signal. One of the inverting circuits is a first start inverting circuit which starts an operation of inverting an input signal in response to a first control signal applied from an external input. One of the inverting circuits except the first start inverting circuit and an inverting circuit immediately following the first start inverting circuit is a second start inverting circuit which starts an operation of inverting an input signal in response to a second control signal. A control signal inputting arrangement serves to input the second control signal to the second start inverting circuit during an interval from a first moment at which the first control signal is inputted into the first start inverting circuit and the first start inverting circuit starts the inverting operation to a second moment at which a pulse edge initially generated by the start of the inverting operation of the first start inverting circuit and travelling while being sequentially inverted by the inverting circuits enters the second start inverting circuit.