Power supply circuit, device and equipment of synchronous rectifier

Abstract

The embodiment of the invention provides a power supply circuit, device and equipment of a synchronous rectifier, and the power supply circuit comprises a first triode Q1, a second triode Q2, a first diode D1, a second diode D2, a third diode D3, a diode group, a first capacitor C1, a second capacitor C2, a switch module, a comparator and an MOS tube Q3. And stable charging current is generated to charge the power supply capacitor, so that the electric quantity of the power supply capacitor is ensured, and the starting reliability of the synchronous rectifier is improved.

Description

technical field

[0001] The present application relates to the technical field of circuit structures, and in particular, to a power supply circuit, device and equipment for a synchronous rectifier. Background technique

[0002] In switching power supplies, diodes are often used for freewheeling, but due to their large conduction voltage drop, the efficiency of switching power supplies will be greatly affected. The synchronous rectifier replaces the diode with a switch tube. Since the on-resistance of the switch tube can be made very small, the voltage drop when the current passes through the switch tube will be very low, so the efficiency will be greatly improved. However, the synchronous rectifier circuit needs to be driven to control the on and off of the switch tube, so the circuit is more complicated and the cost of the circuit is high.

[0003] When solving the high cost problem in the existing solution, a self-powered circuit is usually used to supply power to the sync...

Examples

Embodiment Construction

[0030] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, but not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present application.

[0031] The terms "first", "second" and the like in the description and claims of the present application and the above drawings are used to distinguish different objects, rather than to describe a specific order. Furthermore, the terms "comprising" and "having" and any variations thereof are intended to cover non-exclusive inclusion. For example, a process, method, system, product or device comprising a series of steps or units is not li...

technical field

[0001] The present application relates to the technical field of circuit structures, and in particular, to a power supply circuit, device and equipment for a synchronous rectifier. Background technique

[0002] In switching power supplies, diodes are often used for freewheeling, but due to their large conduction voltage drop, the efficiency of switching power supplies will be greatly affected. The synchronous rectifier replaces the diode with a switch tube. Since the on-resistance of the switch tube can be made very small, the voltage drop when the current passes through the switch tube will be very low, so the efficiency will be greatly improved. However, the synchronous rectifier circuit needs to be driven to control the on and off of the switch tube, so the circuit is more complicated and the cost of the circuit is high.

[0003] When solving the high cost problem in the existing solution, a self-powered circuit is usually used to supply power to the sync...

Examples

Embodiment Construction

[0030] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, but not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present application.

[0031] The terms "first", "second" and the like in the description and claims of the present application and the above drawings are used to distinguish different objects, rather than to describe a specific order. Furthermore, the terms "comprising" and "having" and any variations thereof are intended to cover non-exclusive inclusion. For example, a process, method, system, product or device comprising a series of steps or units is not li...

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