REGULATED MULTIPLE OUTPUT ISOLATED DC TO DC CONVERTER

摘要

Disclosed examples include multiple output DC to DC converters with a buck converter including a half bridge switching circuit and transformer primary winding to provide a first output voltage signal, as well as a boost converter to provide an isolated second output voltage signal. The boost converter includes a transformer secondary winding magnetically coupled with the primary winding to provide a boost converter inductor, a switching circuit, an output diode providing the second output voltage signal, and a PWM controller that synchronizes the boost converter switching with the low side switch of the buck converter based on a sensed voltage of the transformer secondary winding.

主权项

1. A converter circuit, comprising:
first and second input nodes to receive an input voltage signal, a transformer; a first converter circuit, including:
a first switching device coupled between the first input node and a switching node,a second switching device coupled between the switching node and the second input node,a primary winding of the transformer, the primary winding including a first end coupled with the switching node, and a second end coupled with a first output node to provide a first output voltage signal, anda first control circuit to provide a first switching control signal to the first switching device, and to provide a second switching control signal to the second switching device to modulate a voltage at the switching node to control the first output voltage signal; and a second converter circuit, including:
a secondary winding of the transformer, the secondary winding including a first end coupled with a first internal node, and a second end coupled with a second internal node,a first diode connected to the first internal node,a third switching device connected between a cathode of the first diode and the second internal node,a second diode, including an anode connected to the first diode, and a cathode coupled with a second output node to provide a second output voltage signal, anda second control circuit to provide a third switching control signal to the third switching device to control the second output voltage signal.