High-voltage (HV) startup device

摘要

A high-voltage (HV) startup device is disclosed. The HV startup device is connected with a control circuit of a switching power supply and receives a high voltage to provide and increase a triggering voltage received by the control circuit, wherein the control circuit is a pulse width modulator (PWM) or a pulse frequency modulator (PFM). When the triggering voltage reaches to a preset voltage of the control circuit, the control circuit sends out a control signal and the switching power supply uses the control signal to generate a sense signal. The HV startup device receives the control signal or the sense signal to stop providing the triggering voltage.

主权项

1. A high-voltage (HV) startup device, comprising:
a comparator with a positive input terminal thereof connecting with a reference voltage terminal and a negative input terminal thereof connecting with a control circuit and a capacitor of a switching power supply connecting with said control circuit, and receiving a reference voltage of said reference voltage terminal and either a triggering voltage or a zero voltage to send out a switching signal, and said reference voltage is lower than a preset voltage; a sensor connecting with an output terminal of said comparator and said control circuit; and a switch connecting with a sensor, said negative input terminal, said control circuit and said capacitor, and receiving a high voltage, and when said sensor receives said switching signal to turn on said switch using said high voltage to provide and increase said triggering voltage across said capacitor, and when said sensor receives said switching signal and either a control signal or said sense signal, said sensor turns off said switch so that said switch stops providing said triggering voltage across said capacitor, wherein said HV startup device connects with said control circuit of said switching power supply and receives said high voltage to provide and increase said triggering voltage received by said control circuit, and that when said triggering voltage reaches to said preset voltage of said control circuit, said control circuit sends out said control signal and said switching power supply uses said control signal to generate said sense signal, and that said HV startup device receives said control signal or said sense signal to stop providing said triggering voltage.