CONTROL DEVICE FOR POWER CONVERSION CIRCUIT

摘要

The control device 1A includes an on-time information generation circuit 11, a zero cross detecting circuit 12 and a PWM signal generation circuit 13. The on-time information generation circuit 11 inputs at least a power converter circuit information including an output voltage value of a power converter circuit 2, and generates the on-time information about a switch 212. The zero cross detecting circuit 12 detects a time when a inductor current becomes zero by inputting a voltage between both terminals of the inductor 214, and generates a zero cross detection signal when the inductor current became zero. The PWM signal generation circuit 13 inputs the on-time information and the zero cross detection signal, and generates a turn on signal and a turnoff signal. The zero cross detecting circuit 12 has an edge detecting circuit. The zero cross detecting circuit 12 generates a zero cross detection signal when the edge detecting circuit detected an edge appearing in a voltage between both terminals of the inductor 214. The PWM signal generation circuit 13 generates a turn-on signal when a zero cross detection signal was input. The PWM signal generation circuit 13 generates the turn-off signal, when a time based on the on-time information passed, In this way, by the present invention, a change of the inductor current is acquired precisely, and a good critical mode control is carried out.

主权项

1. A control device of a power converter circuit repeating an accumulation of energy to an inductor and releasing the energy accumulated to the inductor at each turn on/turn off timing of a switch or switches, comprising:
an on-time information generation circuit that inputs a power converter circuit information including at least an output voltage value of power converter circuit, and generates on-time information of the switch/switches as a numerical number; a zero cross detecting circuit which detects a time when a current flowing through the inductor became zero by inputting a voltage between both terminals of the inductor, and generates a zero cross detection signal when the current became zero; a PWM signal generation circuit that inputs the on-time information and the zero cross detection signal, and generates a turn on signal and a turnoff signal: wherein the zero cross detecting circuit comprises an edge detecting circuit and a differential circuit provided to an output stage of the edge detecting circuit, and outputs the zero cross detecting signal when the edge detecting circuit detected the edge appeared in a voltage between both terminals of the inductor based on the differential voltage signal generated by the differential circuit; and the PWM signal generation circuit generates the turn on signal, and generates the turnoff signal when a time based on the on-time information is passed.