Unlock instant, AI-driven research and patent intelligence for your innovation.

Overcurrent protection circuit and switching circuit

A technology for protecting circuits and overcurrent, applied in the direction of electronic switches, circuits, electrical components, etc., can solve problems such as damage, and achieve the effect of high-speed protection

Pending Publication Date: 2021-04-09
ORMON CORP
View PDF8 Cites 0 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0002] Semiconductor devices generally have a short-circuit capacity, and when a current exceeding the short-circuit capacity flows, it may cause damage

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Image

Smart Image Click on the blue labels to locate them in the text.
Viewing Examples
Smart Image
  • Overcurrent protection circuit and switching circuit
  • Overcurrent protection circuit and switching circuit
  • Overcurrent protection circuit and switching circuit

Examples

Experimental program
Comparison scheme
Effect test

Embodiment approach 1

[0039] figure 1 It is a block diagram showing a configuration example of the step-up chopper circuit 1 according to the first embodiment. exist figure 1 Among them, the step-up chopper circuit 1 includes: a current-driven switching circuit 10 , an inductor L1 , a diode D1 , and a capacitor C1 . The current-driven switching circuit 10 has a semiconductor switch 14 as a switching element.

[0040] exist figure 1 , the input voltage Vi is applied to the connection point between the anode of the diode D1 and the drain of the semiconductor switch 14 via the inductor L1. The source of the semiconductor switch 14 is grounded. The cathode of the diode D1 is connected to one end of the capacitor C1 that outputs the output voltage Vo, and the other end is grounded.

[0041] In the step-up chopper circuit 1 configured as described above, the inductor L1 generates an electromotive force in a direction that blocks a change in current. Therefore, when the semiconductor switch 14 is swi...

Embodiment approach 2

[0057] In Embodiment 1, when the gate-source voltage Vgs of the semiconductor switch 14 rises, as image 3 As shown, the detection voltage Vocp overshoots. This slows down the drop of the detection voltage Vocp, thereby delaying the start of the protective operation. In addition, as described above, after the overcurrent protection of the short-circuit period Ps, when the response speed of the control unit 12 is slow, an overcurrent repeatedly flows through the semiconductor switch 14, which is not preferable.

[0058] Figure 4 It is a block diagram showing a configuration example of a current-driven switching circuit 10A according to the second embodiment. exist Figure 4 Among them, the current-driven switching circuit 10A differs from the current-driven switching circuit 10 in the following points.

[0059] (1) The overcurrent protection circuit 11A further includes a capacitor Ca connected to the collector and emitter of the transistor Q2 .

[0060] (2) The power sup...

Embodiment approach 3

[0066] Image 6 It is a block diagram showing a configuration example of a current-driven switching circuit 10B according to the third embodiment.

[0067] exist Image 6 Among them, the current-driven switching circuit 10A is different from the current-driven switching circuit 10B in the following points.

[0068] (1) A time constant circuit 18 including a resistor R3 and a capacitor Cb is further provided.

[0069] (2) The time constant circuit 18 is connected in parallel to the collector and emitter of the transistor Q2.

[0070] Accordingly, the time constant until the capacitor Ca discharged to zero potential is charged to the threshold voltage VTH is adjusted so that the time from the protection operation to recovery of the overcurrent protection circuit 11B is longer than that of the overcurrent protection circuit 11A. In addition, the same effect can be obtained by inserting the time constant circuit 18 in the current-driven switching circuit 10 of the first embodim...

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

PUM

No PUM Login to View More

Abstract

In an overcurrent protection circuit for a switching element that undergoes on-off control based on a control voltage, the overcurrent protection circuit comprises: a first transistor that is a PNP type bipolar transistor, and that has an emitter connected to the control voltage; and a second transistor that is an NPN type bipolar transistor, and that has a base that is connected to a collector of the first transistor, the collector that is connected to the base of the first transistor and that is pulled up to a prescribed pull up voltage, and a grounded emitter, wherein with the overcurrent protection circuit, the first and second transistors are turned on when the control voltage exceeds a prescribed first threshold voltage, the control voltage is lowered by lowering of the pull up voltage, and a protection operation that turns off a semiconductor switch starts.

Description

technical field [0001] The invention relates to an overcurrent protection circuit and a switch circuit. Here, the switching circuit refers to, for example, switching circuits such as a step-up chopper circuit, a half-bridge inverter circuit, and a full-bridge inverter circuit. Background technique [0002] Semiconductor devices generally have a short-circuit capacity, and when a current exceeding the short-circuit capacity flows, damage may occur. Overcurrent protection of the semiconductor device can be performed by detecting at high speed an overcurrent flowing through the semiconductor device due to a short circuit and stopping the current flowing through the semiconductor device. [0003] For example, Patent Document 1 provides an overcurrent protection device for a power conversion device, which can change the collector short-circuit detection function at any timing regardless of whether the DC voltage is high, low, or constant. Detects the set level of the voltage, t...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

Application Information

Patent Timeline
no application Login to View More
Patent Type & Authority Applications(China)
IPC IPC(8): H02M1/08H02M3/155H02M7/48
CPCH02M1/08H02M1/32H02M3/156H02M7/5387H03K17/567H03K17/08122H03K17/0826
Inventor 仲田宏宪岩井聪野坂纪元
Owner ORMON CORP