A high-voltage start-up circuit with one-way conduction

Abstract

The invention discloses a one-way conduction high-voltage starting circuit comprising an image current source, a current source generation control module, a charging capacitor, a first P-channel MOS (Metal Oxide Semiconductor) field effect transistor M1 and a second P-channel MOS field effect transistor M2. The one-way conduction high-voltage starting circuit is realized through the following steps: when high-voltage starting is finished, the first P-channel MOS field effect transistor M1 can be regarded as a reverse biased PN junction, and the second P-channel MOS field effect transistor M2 can be regarded as a forward biased PN junction; and the first P-channel MOS field effect transistor M1 is reversely biased, and the reduced voltage is consumed on the P-channel MOS field effect transistor M2, so that the one-way flowability of high-voltage starting current is effectively ensured. The one-way conduction high-voltage starting circuit has the advantages of novel realization method, simple circuit and high reliability.

Description

technical field [0001] The invention belongs to the technical field of integrated circuits, and in particular relates to a circuit which adopts MOSFET to realize unidirectional conduction. Background technique [0002] As a high-efficiency power supply technology, switching power supply is being widely used in various electronic products and equipment due to its excellent energy-saving and power-saving characteristics. Not only that, relevant energy-saving technical specifications have also been issued one after another. [0003] In the prior art, the start-up of the switching power supply control chip is realized through a start-up resistor or a high-voltage start-up circuit. However, in order to achieve high efficiency and energy saving, the energy consumption brought by the method of starting the resistor cannot be ignored. In theory, energy consumption can be reduced by increasing the starting resistance, but the starting time will be significantly increased. The desig...

AI Technical Summary

Problems solved by technology

In the existing technology, the unidirectional conductivity of the diode is mostly used to achieve, but the high-voltage start-up current requires the diode to have a large conduction area, and at the same time, the reverse leakage current of the diode and the influence of the parasitic triode cannot be ignored

[0004] In view of the shortcomings of the existing technology and the high requirements for switching power supplies, as well as the consideration of chip costs, a new method is needed to reliably solve the problem of one-way flow of high-voltage starting current

Images