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AssigneeMicro Linear Corporation
InventorsJeffrey H. Hwang, Donald Yu, Calvin Hsu, Alland Chee
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A combination PFC-PWM integrated circuit converter controller having a power factor correction stage and a pulse-width modulation stage. The power factor correction stage provides unity power factor and a regulated intermediate output voltage by sensing a current in the power factor correction circuit and by sensing the regulated intermediate output voltage in a voltage control loop. The regulated intermediate output voltage is sensed by an error amplifier that includes a current mirror. A dc supply voltage for powering the integrated circuit is generated that is representative of the regulated intermediate output voltage. The dc supply voltage is sensed for an overvoltage protection function. By sensing the intermediate regulated output voltage in the voltage control loop and by sensing the dc supply voltage for overvoltage protection, a component failure is less likely to affect both functions than if a single voltage was sensed for both functions. The pulse-width modulation stage waits a predetermined delay time after start up for the output voltage to rise before beginning the pulse-width modulation function. The delay time is determined by an amount of time taken to charge a capacitor to a predetermined voltage after start up. The capacitor is charged by a current source that is switched on and off according to a clock signal such that the capacitor is charged only a portion of time. Therefore, a larger current source may be used than otherwise which results in more reliable control of the delay time.
A converter controller for controlling a converter, the converter having a power factor correction stage, the power factor correction stage having a control loop for forming a regulated output voltage at an output node wherein the control loop comprises an error amplifier, the error amplifier comprising:
A converter controller for controlling a converter, the converter comprising a power factor correction stage wherein the power factor correction stage comprises means for switching coupled to alternately charge a first inductor and to discharge the first inductor into an output capacitor for forming a regulated output voltage across the output capacitor and means for forming a supply voltage for providing power to the converter controller wherein the means for forming the supply voltage comprises a second inductor inductively coupled to the first inductor, and wherein the converter controller comprises:
A converter controller for controlling a converter, the converter having a pulse-width modulation stage, the pulse width modulation stage comprising:
An error amplifier having an input node and output node, wherein a change in an input voltage level applied to the input node results in a change in an output voltage formed at the output node wherein the change in the output voltage relative to an expected quiescent value for the output voltage is greater than the change in the input voltage relative to an expect quiescent value for the input voltage, the error amplifier comprising:
Dependencies are inferred from the claim text.