SWITCHING CONTROLLER HAVING SWITCHING FREQUENCY HOPPING FOR POWER CONVERTER
First Claim
1. A switching controller having switching frequency hopping for a power converter, comprising:
- a first oscillator, generating a pulse signal for determining a switching frequency of a switching signal;
a maximum duty-cycle circuit, generating a maximum duty-cycle signal in response to the switching signal for determining the switching frequency of the switching signal;
a pattern generator with a second oscillator, generating a digital pattern code in response to a clock signal, wherein the clock signal is generated by the second oscillator;
a programmable capacitor, coupled to the pattern generator and the first oscillator for modulating the switching frequency of the switching signal in response to the digital pattern code; and
a PWM circuit, coupled to the first oscillator and the maximum duty-cycle circuit for generating the switching signal in accordance with the pulse signal and the maximum duty-cycle signal, a maximum on-time of the switching signal being limited by the maximum duty-cycle signal, wherein the switching signal is utilized to switch a transformer of the power converter.
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Accused Products
Abstract
A switching controller having switching frequency hopping for a power converter includes an oscillator generating a pulse signal for determining a switching frequency of a switching signal, a maximum duty-cycle circuit generating a maximum duty-cycle signal in response to the switching signal for determining the switching frequency of the switching signal, a pattern generator generating a digital pattern code in response to a clock signal, a programmable capacitor coupled to the pattern generator and the oscillator for modulating the switching frequency of the switching signal in response to the digital pattern code, and a PWM circuit coupled to the oscillator and the maximum duty-cycle circuit for generating the switching signal in accordance with the pulse signal and the maximum duty-cycle signal. A maximum on-time of the switching signal is limited by the maximum duty-cycle signal. The switching signal is utilized to switch a transformer of the power converter.
17 Citations
10 Claims
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1. A switching controller having switching frequency hopping for a power converter, comprising:
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a first oscillator, generating a pulse signal for determining a switching frequency of a switching signal; a maximum duty-cycle circuit, generating a maximum duty-cycle signal in response to the switching signal for determining the switching frequency of the switching signal; a pattern generator with a second oscillator, generating a digital pattern code in response to a clock signal, wherein the clock signal is generated by the second oscillator; a programmable capacitor, coupled to the pattern generator and the first oscillator for modulating the switching frequency of the switching signal in response to the digital pattern code; and a PWM circuit, coupled to the first oscillator and the maximum duty-cycle circuit for generating the switching signal in accordance with the pulse signal and the maximum duty-cycle signal, a maximum on-time of the switching signal being limited by the maximum duty-cycle signal, wherein the switching signal is utilized to switch a transformer of the power converter. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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Specification