Pulse generator circuit and communication apparatus
A pulse generator circuit that outputs pulses having a predetermined shape from an output terminal based on a start signal includes a timing generator circuit that generates (n) signals (n is an integer greater than or equal to 2), a pulse width signal generator circuit that generates a first pulse width signal and a second pulse width signal a first filter circuit limiting the band of the first pulse width signal, a second filter circuit limiting the band of the second pulse width signal, first and second power supplies, a first variable impedance circuit controlled by the first filter circuit, a second variable impedance circuit controlled by the second filter circuit, and a switching circuit that alternately connects the output terminal to the first power supply using a logic function value based on at least part of the n signals.
1. A pulse generator circuit that outputs pulses having a predetermined shape from an output terminal based on a start signal, the pulse generator circuit comprising:
a timing generator circuit that generates (n) signals (n is an integer greater than or equal to 2), the phases of which sequentially change at predetermined time intervals from the point when the phase of the start signal changes;
a pulse width signal generator circuit that generates a first pulse width signal and a second pulse width signal having a pulse width that corresponds to the duration of the pulses to be generated based on the start signal;
a first filter circuit to which the first pulse width signal is inputted, the first filter circuit limiting the band of the first pulse width signal;
a second filter circuit to which the second pulse width signal is inputted, the second filter circuit limiting the band of the second pulse width signal;
first and second power supplies that supply predetermined potentials;
a first variable impedance circuit whose impedance value is controlled by the output value from the first filter circuit;
a second variable impedance circuit whose impedance value is controlled by the output value from the second filter circuit; and
a switching circuit that alternately connects the output terminal to the first power supply via the first variable impedance circuit or the second power supply via the second variable impedance circuit using a logic function value based on at least part of the n signals.
2. The pulse generator circuit according to claim 1 ,
wherein the timing generator circuit includes delay circuits connected in tandem, each of the delay circuits generating a predetermined amount of delay.
3. The pulse generator circuit according to claim 1 ,
wherein the timing generator circuit is comprised of a ring oscillator circuit at least part of which including a delay circuit that generates a predetermined amount of delay.
4. The pulse generator circuit according to claim 1 ,
wherein the first variable impedance circuit is comprised of a transistor controlled by the output value from the first filter circuit, and the second variable impedance circuit is comprised of a transistor controlled by the output value from the second filter circuit.
5. A communication apparatus comprising the pulse generator circuit according to claim 1 .