Field effect transistor charging-based semiconductor starting device and manufacturing process

Abstract

The invention discloses a field effect transistor charging-based semiconductor starting device, which comprises a field effect transistor, an electronic switch, a low-voltage power module, a resistor, a capacitor and a feedback control module, wherein the capacitor is charged directly by the field effect transistor; the feedback control module is matched with the electronic switch and the low-voltage power module to control the field effect transistor to be switched on and off according to the magnitude of output voltage. The invention also discloses a manufacturing process for the semiconductor starting device. The manufacturing of the field effect transistor Q1 and the low-voltage power module is mainly improved. According to the semiconductor starting device, the capacitor is charged directly by the field effect transistor, and the field effect transistor is low in resistance and power consumption when being switched on, so that higher charging current can be generated in case of lower input voltage, and the power consumption and the heat value of the resistor can be lowered; after charging, the feedback control module switches on the electronic switch and switches off the field effect transistor to stop charging, and leakage current is very low, so that the aims of reducing loss and improving the power efficiency are fulfilled.

Description

technical field [0001] The invention relates to an integrated circuit starting device, in particular to a semiconductor starting device based on field effect tube charging and a manufacturing process. Background technique [0002] The switching power supply starting circuit is a commonly used starting device in integrated circuits. At present, the structure (or basic principle) of most switching power supply starting circuits is as follows: figure 1 As shown, it includes resistor R1, capacitor C1, Zener diode ZD1, auxiliary winding N1, diode D1 and control IC. The current is greater than the starting current of the control IC. After the voltage of the capacitor C1 rises to the normal operating voltage of the control IC, the control IC starts to work. When the output voltage Vout of the starting circuit is stable, the voltage generated by the auxiliary winding N1 is rectified by the diode D1 and the capacitor C1 supplies power to the control IC after filtering, the VCC and o...

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Problems solved by technology

[0003] The defect of the above-mentioned traditional switching power supply start-up circuit is: when the input voltage Vin range is wide, in order to ensure that the control IC can provide enough power at the lowest input voltage Starting current, so that the switching power supply can start normally, then the resistance value of resistor R1 should not be too large

Since the resistor R1 is always connected to the input terminal, the power consumption generated by the resistor R1 is P=(Vin-VCC)2 / R1. Obviously, if the switching power supply is working at a high voltage input, the power consumption on the resistor R1 will be very high. If it is large, it will affect the power conversion efficiency, heat dissipation and reliability, and reduce the power supply efficiency. Moreover, the resistor R1 must use a high-power resistor, so that the switching power supply is large in size and high in cost.

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