Abstract: A frequency jitter generation circuit having a voltage generator and an oscillator circuit is provided. The voltage generator receives an input voltage and converts the input voltage into an upper reference voltage output to the oscillator circuit. Voltage level of the upper reference voltage is varying. The oscillator circuit is coupled with the voltage generator. Voltage level of a reference voltage in the oscillator circuit is oscillated between the upper reference voltage and a lower reference voltage to generate a frequency signal with a jitter based on the variation of the upper reference voltage.

Abstract: A frequency jitter generation circuit having a voltage generator and an oscillator circuit is provided. The voltage generator receives an input voltage and converts the input voltage into an upper reference voltage output to the oscillator circuit. Voltage level of the upper reference voltage is varying. The oscillator circuit is coupled with the voltage generator. Voltage level of a reference voltage in the oscillator circuit is oscillated between the upper reference voltage and a lower reference voltage to generate a frequency signal with a jitter based on the variation of the upper reference voltage.

Abstract: A switching power supply apparatus with current output limit, which utilizes a voltage sampling controller for sampling the feedback voltage to acquire a knee voltage. Moreover, the knee voltage is computed by the square-root operation and error elimination operation respectively. According to the result of the computing, the switching of the power switch is controlled so as to stabilize the output voltage and limit the output current.