Primary-side controlled power converter with an RC network and method thereof
View Patent ↗This invention provides a primary-side controlled power converter comprising: an RC network coupled to an auxiliary winding of a transformer of the primary-side controlled power converter to detect a reflected voltage of the transformer for generating a reflected signal, and a controller coupled to the RC network to receive the reflected signal for generating a switching signal; wherein the RC network develops a zero to provide a high-frequency path for shortening a rising time and a settling time of the reflected signal.
1. A primary-side controlled power converter, comprising:
an RC network coupled to an auxiliary winding of a transformer of the primary-side controlled power converter to detect a reflected voltage of the transformer to generate a reflected signal; and
a controller coupled to the RC network to receive the reflected signal and generate a switching signal;
wherein the RC network comprises a high-pass filter coupled to the auxiliary winding to detect the reflected voltage; and
wherein the high-pass filter develops a zero to provide a high-frequency path to shorten a rising time and a settling time of the reflected signal.
2. The power converter as claimed in claim 1 , wherein the RC network comprises:
a first resistor coupled to the auxiliary winding to detect the reflected voltage of the transformer;
a third resistor serially connected with the first resistor;
a second resistor connected from the third resistor to ground;
a high-pass capacitor parallel connected to the first resistor;
a low-pass capacitor parallel connected to the second resistor;
wherein the controller is coupled to a join of the second resistor and the low-pass capacitor.
3. The power converter as claimed in claim 2 , wherein the first resistor has a first terminal and a second terminal, the first terminal of the first resistor being coupled to the auxiliary winding of the transformer; the third resistor has a first terminal and a second terminal, the first terminal of the third resistor being connected to the second terminal of the first resistor.
4. The power converter as claimed in claim 1 , wherein the controller generates the switching signal according to the reflected voltage for regulating an output voltage of the power converter.
5. The power converter as claimed in claim 1 , wherein the controller generates the switching signal according to the reflected voltage for regulating an output current of the power converter.
6. A primary-side controlled power converter with a network, comprising:
a network including a high-pass filter coupled to an auxiliary winding of a transformer of the primary-side controlled power converter to detect a reflected voltage of the transformer, said network further including:
a resistor coupled to the auxiliary winding to detect the reflected voltage of the transformer; and
a high-pass capacitor connected to the resistor in parallel; and
a controller coupled to the resistor to receive the reflected voltage;
wherein the high-pass filter including the resistor and the resistor and the high-pass capacitor develops a zero of the network, and the controller generates a switching signal according to the reflected voltage.
7. The power converter as claimed in claim 6 , wherein a reflected signal is generated at a join of the network and the controller, and the resistor and the high-pass capacitor provide a high-frequency path of the network to shorten a rising time and a settling time of the reflected signal.
8. The power converter as claimed in claim 6 , wherein the controller generates the switching signal according to the reflected voltage for regulating an output voltage of the power converter.
9. The power converter as claimed in claim 6 , wherein the controller generates the switching signal according to the reflected voltage for regulating an output current of the power converter.
10. A method for detecting a reflected voltage of a transformer of a primary-side controlled power converter, comprising:
coupling an RC network between an auxiliary winding of the transformer of the primary-side controlled power converter and a controller, wherein the RC network comprises a high-pass filter coupled to the auxiliary winding to detect the reflected voltage and develops a zero to provide a high-frequency path;
receiving a reflected signal generated at a join of the RC network and the controller;
generating a switching signal according to the reflected signal through the controller.
11. The method as claimed in claim 10 , the RC network comprises:
a first resistor coupled to the auxiliary winding;
a third resistor serially connected with the first resistor;
a second resistor connected from the third resistor to ground;
a high-pass capacitor parallel connected to the first resistor;
a low-pass capacitor parallel connected to the second resistor;
wherein the controller is coupled to a join of the second resistor and low-pass capacitor.