Controller for increasing efficiency of a power converter and a related method thereof

Abstract

A controller for increasing efficiency of a power converter includes a comparison module and a gate signal generation unit. The comparison module is used for generating a detection voltage according to a direct current (DC) input voltage of a primary side of the power converter, and comparing the detection voltage with a predetermined value to generate a comparison result. The gate signal generation unit is used for changing a sink current flowing through a gate pin of the controller according to the comparison result, wherein the gate pin of the controller is coupled to a power switch of the primary side of the power converter.

What is claimed is: 
     
         1 . A controller for increasing efficiency of a power converter, the controller comprising:
 a comparison module for generating a detection voltage according to a direct current (DC) input voltage of a primary side of the power converter, and comparing the detection voltage with a predetermined value to generate a comparison result; and   a gate signal generation unit for changing a sink current flowing through a gate pin of the controller according to the comparison result, wherein the gate pin is coupled to a power switch of the primary side of the power converter.   
     
     
         2 . The controller of  claim 1 , wherein the gate signal generation unit is further used for generating a gate control signal to the power switch, and the power switch is turned on and turned off according to the gate control signal. 
     
     
         3 . The controller of  claim 1 , wherein the gate signal generation unit changing the sink current according to the comparison result comprises the comparison module generating the comparison result and the gate signal generation unit increasing the sink current according to the comparison result when the detection voltage is less than the predetermined value. 
     
     
         4 . The controller of  claim 1 , wherein the gate signal generation unit changing the sink current according to the comparison result comprises the comparison module generating the comparison result and the gate signal generation unit decreasing the sink current according to the comparison result when the detection voltage is greater than the predetermined value. 
     
     
         5 . The controller of  claim 1 , further comprising:
 a high voltage pin for receiving the DC input voltage from the primary side of the power converter, wherein the comparison module comprises:
 a detection voltage generation unit coupled to the high voltage pin for generating the detection voltage according to the DC input voltage; and 
 a comparator coupled to the detection voltage generation unit for comparing the detection voltage with the predetermined value to generate the comparison result. 
   
     
     
         6 . The controller of  claim 1 , further comprising:
 an auxiliary pin for receiving an auxiliary voltage from a voltage divider coupled to an auxiliary winding of the power converter, wherein the auxiliary voltage corresponds to the DC input voltage, and the comparison module comprises:
 a detection voltage generation unit coupled to the auxiliary pin for generating the detection voltage according to the auxiliary voltage; and 
 a comparator coupled to the detection voltage generation unit for comparing the detection voltage with the predetermined value to generate the comparison result. 
   
     
     
         7 . A controller for increasing efficiency of a power converter, the controller comprising:
 an enable signal generation unit for generating an enable signal corresponding to a duty cycle of a gate control signal according to a DC input voltage corresponding to a primary side of the power converter and a feedback voltage corresponding to a secondary side of the power converter, wherein the feedback voltage corresponds to an output voltage of the secondary side of the power converter; and   a gate signal generation unit for changing a sink current flowing through a gate pin of the controller according to the enable signal, wherein the gate pin is coupled to a power switch of the primary side of the power converter, and the gate signal generation unit is further used for generating a gate control signal to the power switch.   
     
     
         8 . The controller of  claim 7 , wherein the enable signal generation unit generating the enable signal corresponding to the duty cycle of the gate control signal is the enable signal generation unit generating the enable signal when the duty cycle of the gate control signal is greater than a predetermined value. 
     
     
         9 . The controller of  claim 8 , wherein the gate signal generation unit changing the sink current flowing through the gate pin of the controller according to the enable signal is the gate signal generation unit increasing the sink current according to the enable signal when the duty cycle of the gate control signal is greater than the predetermined value. 
     
     
         10 . The controller of  claim 7 , wherein the enable signal generation unit generating the enable signal corresponding to the duty cycle of the gate control signal is the enable signal generation unit generating the enable signal when the duty cycle of the gate control signal is less than a predetermined value. 
     
     
         11 . The controller of  claim 10 , wherein the gate signal generation unit changing the sink current flowing through the gate pin of the controller according to the enable signal is the gate signal generation unit decreasing the sink current according to the enable signal when the duty cycle of the gate control signal is less than the predetermined value. 
     
     
         12 . The controller of  claim 7 , further comprising:
 a high voltage pin for receiving the DC input voltage from the primary side of the power converter.   
     
     
         13 . A method for increasing efficiency of a power converter, wherein a controller applied to the method comprises a high voltage pin, a comparison module, and a gate signal generation unit, and the comparison module comprises a detection voltage generation unit and a comparator, the method comprising:
 the high voltage pin receiving a DC input voltage from a primary side of the power converter;   the detection voltage generation unit generating a detection voltage according to the DC input voltage;   the comparator comparing the detection voltage with a predetermined value to generate a comparison result; and   the gate signal generation unit changing a sink current flowing through a gate pin of the controller according to the comparison result.   
     
     
         14 . The method of  claim 13 , wherein the comparator comparing the detection voltage with the predetermined value to generate the comparison result, and the gate signal generation unit changing the sink current according to the comparison result comprises:
 the comparison module generating the comparison result when the detection voltage is less than the predetermined value; and   the gate signal generation unit increasing the sink current according to the comparison result.   
     
     
         15 . The method of  claim 13 , wherein the comparator comparing the detection voltage with the predetermined value to generate the comparison result, and the gate signal generation unit changing the sink current according to the comparison result comprises:
 the comparison module generating the comparison result when the detection voltage is greater than the predetermined value; and   the gate signal generation unit decreasing the sink current according to the comparison result.   
     
     
         16 . A method for increasing efficiency of a power converter, wherein a controller applied to the method comprises an auxiliary pin, a comparison module, and a gate signal generation unit, and the comparison module comprises a detection voltage generation unit and a comparator, the method comprising:
 the auxiliary pin receiving an auxiliary voltage from a voltage divider coupled to an auxiliary winding of the power converter, wherein the auxiliary voltage corresponds to a DC input voltage;   the detection voltage generation unit generating a detection voltage according to the auxiliary voltage;   the comparator comparing the detection voltage with a predetermined value to generate a comparison result; and   the gate signal generation unit changing a sink current flowing through a gate pin of the controller according to the comparison result, wherein the gate pin is coupled to a power switch of a primary side of the power converter.   
     
     
         17 . The method of  claim 16 , wherein the comparator comparing the detection voltage with the predetermined value to generate the comparison result, and the gate signal generation unit changing the sink current according to the comparison result comprises:
 the comparison module generating the comparison result when the detection voltage is less than the predetermined value; and   the gate signal generation unit increasing the sink current according to the comparison result.   
     
     
         18 . The method of  claim 16 , wherein the comparator comparing the detection voltage with the predetermined value to generate the comparison result, and the gate signal generation unit changing the sink current according to the comparison result comprises:
 the comparison module generating the comparison result when the detection voltage is greater than the predetermined value; and   the gate signal generation unit decreasing the sink current according to the comparison result.   
     
     
         19 . A method for increasing efficiency of a power converter, wherein a controller applied to the method comprises a high voltage pin, an enable signal generation unit, and a gate signal generation unit, the method comprising:
 the high voltage pin receiving a DC input voltage from a primary side of the power converter;   the enable signal generation unit generating an enable signal corresponding to a duty cycle of a gate control signal according to the DC input voltage and a feedback voltage corresponding to a secondary side of the power converter, wherein the feedback voltage corresponds to an output voltage of the secondary side of the power converter; and   the gate signal generation unit changing a sink current flowing through the gate pin of the controller according to the enable signal.   
     
     
         20 . The method of  claim 19 , wherein the enable signal generation unit generating the enable signal corresponding to the duty cycle of the gate control signal comprises:
 the enable signal generation unit generating the enable signal when the duty cycle of the gate control signal is greater than a predetermined value.   
     
     
         21 . The method of  claim 20 , wherein the gate signal generation unit changing the sink current flowing through the gate pin of the controller according to the enable signal comprises:
 the gate signal generation unit increasing the sink current according to the enable signal when the duty cycle of the gate control signal greater than the predetermined value.   
     
     
         22 . The method of  claim 19 , wherein the enable signal generation unit generating the enable signal corresponding to the duty cycle of the gate control signal comprises:
 the enable signal generation unit generating the enable signal when the duty cycle of the gate control signal is less than a predetermined value.   
     
     
         23 . The method of  claim 22 , wherein the gate signal generation unit changing the sink current flowing through the gate pin of the controller according to the enable signal comprises:
 the gate signal generation unit decreasing the sink current according to the enable signal when the duty cycle of the gate control signal is less than the predetermined value.