Ultra-fast hardware current-limiting circuit

Abstract

The invention provides an ultra-fast hardware current-limiting circuit which comprises a holding circuit and a voltage comparison circuit. The holding circuit comprises a first voltage comparator, a first resistor and a second resistor, one end of the first resistor and one end of the second resistor are connected with the in-phase input end of the first voltage comparator, the other end of the first resistor is provided with first reference voltage, the other end of the second resistor is connected with the output end of the first voltage comparator, the inverting input end of the first voltage comparator is connected with a logical combination output signal of one PWM drive signal or multiple PWM drive signals, and the output end of the voltage comparison circuit is connected with the output end of the first voltage comparator and used for outputting low-level current-limiting trigger enable signals or high impedance. The ultra-fast hardware current-limiting circuit is short in delay time, quick in response and high in circuit reliability, the number of components which are used is small, the service life of a switch tube is prolonged, and one or more PWM drive signals can be processed at the same time.

Description

technical field [0001] The invention relates to the technical field of electronic circuits, in particular to an extremely fast hardware current limiting circuit. Background technique [0002] At present, as the requirements for power supply reliability are getting higher and higher, the uninterruptible power supply system can provide a safe, stable and continuous power supply guarantee for electrical equipment because it can continuously supply power to electrical equipment, and its use is very widely, has become a research hotspot. [0003] In the switching power supply system with uninterruptible power supply, the switch tube has a limited maximum current value. When the current value flowing through the switch tube is greater than the maximum current value limited by the switch tube, it will cause damage to the switch tube, thus affecting the entire continuous current. reliability and safety of the power supply system. Therefore, in order to improve the reliability of t...

AI Technical Summary

Problems solved by technology

[0003] In the switching power supply system with uninterruptible power supply, the switch tube has a limited maximum current value. When the current value flowing through the switch tube is greater than the maximum current value limited by the switch tube, it will cause damage to the switch tube, thus affecting the entire continuous current. Reliability and safety of electric power supply system

Therefore, in order to improve the reliability of the uninterruptible power supply system, we need to limit the current peak value in the circuit. At present, the commonly used current limiting method is software current limiting, that is, limiting the current change in the circuit through software control; In the power supply circuit, we generally use ferrite inductors as energy storage components. However, as the inductance value of the inductor becomes smaller and smaller, the ripple current in the circuit will become larger and larger, especially when the external conditions deteriorate sharply. Under the circumstances, it will eventually cause a very large peak current in the circuit, which will threaten the use of the switch tube and affect the reliability of the power supply system

In addition, due to the large delay and low reliability of software current limiting, it is far from meeting the needs of high reliability circuits.

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