Patent ID: 8067929
Filing Date: 2011-11-29
Classification: B01J

Abstract:
1. A DC to DC converter circuit, comprising: circuitry for generating a PWM waveform signal of the DC to DC converter responsive to an input voltage and a monitored output voltage, the circuitry further comprising a high side switching transistor connected between the input voltage and the phase node and a low side switching transistor connected between the phase node and ground; an output filter connected to the circuitry for generating the PWM waveform signal, the output filter including an inductor having a first side connected to the phase node and a second side connected to an output voltage node; detection circuitry for detecting zero current crossings in the inductor responsive to a voltage across the high side switching transistor and a voltage across the low side switching transistor; and wherein the detection circuitry detects the zero current crossing in the inductor using the turn on time of a high side switching transistor at a frequency range causing a turn on time of a low side switching transistor to be too short to detect the zero current crossing in the inductor using the low side switching transistor.