초록 ▼

A switching regulator for reducing electromagnetic interference (EMI) includes a PWM controller which incorporates a varying frequency oscillator for controlling the operating frequency of the switching regulator. The varying frequency oscillator provides an oscillating signal having a continuously

A switching regulator for reducing electromagnetic interference (EMI) includes a PWM controller which incorporates a varying frequency oscillator for controlling the operating frequency of the switching regulator. The varying frequency oscillator provides an oscillating signal having a continuously varying frequency about the center switching frequency of the switching regulator. The varying frequency oscillating signal causes the operating frequency of the switching regulator to vary, spreading out the EMI noise generated by the switching regulator and effectively reducing the peak energy of the EMI noise.

대표청구항 ▼

[I claim:] [1.]a PWM controller, said controller comprising:a varying frequency oscillator for controlling a switching frequency of at least one switching transistor coupled to said PWM controller, said oscillator providing an oscillating signal having a continuously varying frequency; anda control

[I claim:] [1.]a PWM controller, said controller comprising:a varying frequency oscillator for controlling a switching frequency of at least one switching transistor coupled to said PWM controller, said oscillator providing an oscillating signal having a continuously varying frequency; anda control circuit for controlling a duty cycle of said at least one switching transistor, said control circuit coupled to receive said oscillating signal as a logic control signal from said varying frequency oscillator and generate a duty cycle control signal.