CPC H03K 17/08122 (2013.01) [H03K 17/04123 (2013.01)] | 18 Claims |
1. A constant-power control method of a switching device, comprising:
using a voltage (Vs) across the switching device to generate a first signal (Vc) on a terminal of a capacitor connected to ground;
generating a second signal representing a current proportional to Vs; and
generating a third signal to control first and second driver switches to generate a pulse width modulated signal from the first (Vc) signal to control the switching device by:
charging the capacitor in response to opening a switch across the capacitor; and
changing the status of the third signal when the capacitor has reached a reference voltage (Vref);
wherein a duration (ta) of the pulse width modulation signal in an active phase is at least partially based on the first signal.
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