Power converter apparatus

摘要

A power converter having reduced switching transients includes a conversion inductance, a pulse width modulation (PWM) controller, a conversion inductance, and a switch transistor. A low pass filter is connected between the PWM controller and the switch transistor to filter a PWM signal produced by the PWM controller and produce a filtered PWM signal. The switching transistor switches current through the conversion inductance responsive to the filtered PWM signal. The low pass filter filters out harmonic content of the PWM signal that is above the fundamental frequency in a way that maintains most of the harmonic content of the PWM signal to substantially eliminate higher harmonic elements which are conventionally responsible for transients across the conversion inductance.

主权项

1. A power converter, comprising:
a pulse width modulation (PWM) controller that produces a PWM signal in correspondence to a feedback input, the PWM signal having a fundamental frequency; a low pass filter, having a plurality of poles, connected to the PWM controller, the low pass filter having a corner frequency that is above at least ten times the fundamental frequency of the PWM signal, the low pass filter producing a filtered PWM signal having substantially 99 percent of harmonic content, by power, in the filtered signal with higher frequency harmonic components eliminated; and a switching transistor having a control terminal coupled to the low pass filter to receive the filtered PWM signal having the harmonic content, the switching transistor further coupled in series with a primary winding of a transformer responsive to the filtered PWM signal; and wherein the number of poles for the plurality of poles of the low pass filter being based on:
sufficient attenuation needed to eliminate interference of unwanted harmonics;sufficient attenuation needed eliminate interference across the primary winding; andwithout the use of a transient suppression network.