Starting circuit for integrated circuit of power factor correction controller

Abstract

The invention provides a starting circuit for an integrated circuit of a power factor correction control chip, which comprises a rectification circuit and a charge pump circuit, wherein the output ofthe rectification circuit is connected to a power supply pin of the chip by a starting resistor; and the output end of the charge pump circuit is connected with the power supply pin of the chip. The starting circuit comprises a first current path and a second current path, wherein the input end of the first current path is connected with the starting resistor, and the output end of the first current path is connected with the power supply pin of the chip; the input end of the second current path is connected with the starting resistor, and the output end of the second current path is connectedwith the earth potential; when the power is switched on, the first current path is switched on, and the second current path is switched off; and when the power factor correction control chip operatesnormally, the first current path is switched off, and the second current path is switched on.

Description

technical field [0001] The invention relates to a starting circuit, in particular to a starting circuit applied to a power factor correction (PFC) controller integrated circuit (IC). Background technique [0002] Typically, the PFC controller IC takes its supply current from a charge pump circuit connected to the boost inductor's auxiliary winding. However, no high-frequency current flows through the boost inductor until the IC is powered up. To start an IC, the usual solution is to connect a start-up resistor between the direct current (DC) rail and the supply pin of the IC. Since most of the blocks in the IC have not yet started to work during the start-up phase, the current required to activate the IC is usually less than 1mA. Depending on the rectified DC rail voltage, the value of the startup resistor is typically on the order of hundreds of kilohms. [0003] figure 1 A prior art start-up circuit is shown. The start-up circuit includes a rectifier circuit composed ...

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Problems solved by technology

[0004] The disadvantage of the above circuit is that after the charge pump circuit starts to work, the starting resistor R1 consumes a large amount of power

Although the resistance value can be increased to reduce the power loss, the start-up time of the system is sacrificed because the increased resistance simultaneously reduces the current flowing through the start-up resistor during start-up

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