ACTIVE POWER FACTOR CORRECTION CONTROL CIRCUIT, CHIP AND LED DRIVING CIRCUIT THEREOF

摘要

In one embodiment, an active power factor correction (APFC) control circuit, configured to generate a pulse-width modulation (PWM) control signal to control the operation of a power converter, can include: (i) an inductor current zero crossing detection circuit coupled to a common node between a power switch of the power converter and a first switch that are coupled in series, where the inductor current zero crossing detection circuit is configured to generate a comparison signal based on a voltage signal at the common node; (ii) the comparison signal being activated when an inductor current of the power converter decreases to zero; and (iii) the APFC control circuit being configured as a source driver, wherein a control terminal of the power switch is coupled to a constant voltage supply.

主权项

1. An active power factor correction (APFC) control circuit, configured to generate a pulse-width modulation (PWM) control signal to control the operation of a power converter, the APFC control circuit comprising:
a) an inductor current zero crossing detection circuit coupled to a source of a power switch of said power converter, wherein said inductor current zero crossing detection circuit is configured to generate a comparison signal based on a voltage at said source of said power switch; b) said comparison signal being activated when an inductor current of said power converter decreases to zero; and c) said APFC control circuit being configured to drive said source of said power switch.