Patent ID: 8421431
Filing Date: 2013-04-16
Classification: H03K

Abstract:
1. A frequency jitter controller for a power converter, comprising: a first capacitance unit; a second capacitance unit; a first charge-discharge control unit, coupled to the first capacitance unit, for charging the first capacitance unit to a crossing-voltage during a charging phase and discharging the first capacitance unit to a reference voltage during a discharging phase, wherein a maximum value of the crossing-voltage is associated with a rising rate of a voltage on the second capacitance unit; a second charge-discharge control unit, coupled to the second capacitance unit, for charging the second capacitance unit to the crossing-voltage during the charging phase and discharging the second capacitance unit to a clamp voltage during the discharging phase; a comparing unit, having a first input terminal, a second input terminal and a third input terminal respectively coupled to the first capacitance unit, the second capacitance unit and the reference voltage, and an output terminal outputting a pulse signal, wherein the comparing unit compares voltages of the first capacitance unit and the second capacitance unit during the charging phase and compares the voltage of the first capacitance unit and the reference voltage during the discharging phase; and a control unit, coupled to the output terminal of the comparing unit, for generating a frequency jitter control signal according to the pulse signal to adjust the rising rate of the voltage on the second capacitance unit, so as to change a frequency of the pulse signal.