Over-current protection low-side switching circuit and device

Abstract

The invention discloses a low-side switching circuit for overcurrent protection, which belongs to the technical field of analog electronics, and comprises a first resistor of which one end is electrically connected with a control end, the other end is electrically connected with the G end of an mos tube, the D end of the mos tube is electrically connected with one end of a fifth resistor, the other end of the fifth resistor is electrically connected with an execution end and one end of a sixth resistor, and the sixth resistor is electrically connected with the execution end. The other end of the sixth resistor is electrically connected with the feedback end and one end of the seventh resistor, the S end of the mos tube and the other end of the seventh resistor are electrically connected with the GND end, the G end of the mos tube is electrically connected with one end of the eighth resistor, and the other end of the eighth resistor is electrically connected with the GND end. According to the low-side switching circuit and device for overcurrent protection, a low-side switching chip is replaced, the function is closed when the current is too large, meanwhile, the current is fed back to the MCU, damage to devices in a low-side driving circuit is avoided, and meanwhile the cost is reduced.

Description

Technical Field

[0001] The invention discloses a low-side switch circuit for overcurrent protection, belonging to the technical field of analog electronics. Background Art

[0002] Existing automobile combination instruments are usually equipped with a low-side driver circuit module, and the low-side driver circuit module is required to have a function of detecting a low-side load open circuit.

[0003] Low side switch chips have broad application prospects in new energy vehicles and industry. Low side switches use the performance of transistors to be used as driving switches. In the prior art, low side switches are generally used as relays, motor drivers, etc. When the low side switch is used, the low side switch is powered by its own internal chip power supply. When the chip is working normally, it is necessary to ensure that the power supply inside the chip is sufficient to ensure stable and reliable operation of the switch. However, in the prior art, when the current is too large, the low side switch chip burns out, causing other safety risks and frequent chip replacement resulting in high costs. Summary of the invention

[0004] The purpose of the present invention is to solve the problem in the prior art that when the current is too large, the low-side switch chip burns out, resulting in high cost and other safety risks caused by replacing the chip, and to propose a low-side switch circuit and device with overcurrent protection.

[0005] The problem to be solved by the present invention is achieved by the following technical solutions:

[0006] A low-side switch circuit for overcurrent protection comprises a first resistor having one end electrically connected to a control end, and the other end electrically connected to a G end of a MOS tube, the D end of the MOS tube being electrically connected to one end of a fifth resistor, the other end of the fifth resistor being electrically connected to an execution end and one end of a sixth resistor respectively, the other end of the sixth resistor being electrically connected to a feedback end and one end of a seventh resistor respectively, the S end of the MOS tube and the other end of the seventh resistor being electrically connected to a GND end respectively, the G end of the MOS tube being electrically connected to one end of an eighth resistor, and the other end of the eighth resistor being electrically connected to the GND end.

[0007] Preferably, it also includes a second transistor whose C end is electrically connected to the other end of the first resistor, the B end of the second transistor is electrically connected to one end of the ninth resistor, one end of the ninth resistor is electrically connected to one end of the second resistor, the other end of the ninth resistor and the E end of the second transistor are respectively electrically connected to the GND end, the other end of the second resistor is electrically connected to the C end of the first transistor, the B end of the first transistor is respectively electrically connected to one end of the third resistor and the fourth resistor, the other end of the fourth resistor is electrically connected to one end of the fifth resistor, and the E end of the first transistor is respectively electrically connected to the other end of the third resistor and the fifth resistor.

[0008] Preferably, one end of the sixth resistor is electrically connected to one end of the first capacitor, and the other end of the first capacitor is electrically connected to a GND terminal.

[0009] Preferably, the other end of the sixth resistor is electrically connected to one end of the second capacitor, and the other end of the second capacitor is electrically connected to a GND terminal.

[0010] A low-side switch device for overcurrent protection comprises the low-side switch circuit for overcurrent protection.

[0011] The present invention has the following beneficial effects compared with the prior art:

[0012] The present invention provides a low-side switch circuit and device for overcurrent protection, which replaces the low-side switch chip, turns off the function when the current is too large, and feeds back to the MCU at the same time, avoiding damage to the components in the low-side drive circuit and reducing the cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 The invention discloses a circuit diagram of a low-side switch circuit for overcurrent protection. DETAILED DESCRIPTION

[0014] The following is based on the attached Figure 1 The present invention is further described:

[0015] The technical solution of the present invention will be described clearly and completely below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0016] In the description of the present invention, it should be noted that the terms "center", "up", "down", "left", "right", "vertical", "horizontal", "inside", "outside", etc. indicate directions or positional relationships based on the directions or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction. Therefore, they cannot be understood as limitations on the present invention.

[0017] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0018] like Figure 1 As shown, the first embodiment of the present invention provides a low-side switch circuit for overcurrent protection based on the prior art, including a terminal connected to a control terminal Switch1 LSCtrl The first resistor R1001 is electrically connected, and the other end is electrically connected to the G end of the MOS tube Q1003. The D end of the MOS tube Q1003 is electrically connected to one end of the fifth resistor R1005. The other end of the fifth resistor R1005 is electrically connected to the execution end Switch1 LS and one end of the sixth resistor R1006 is electrically connected, and the other end of the sixth resistor R1006 is respectively connected to the feedback end Switch1 LSMCU The S end of the MOS tube Q1003 and the other end of the seventh resistor R1007 are electrically connected to the GND end respectively, the G end of the MOS tube Q1003 is electrically connected to one end of the eighth resistor R1008, and the other end of the eighth resistor R1008 is electrically connected to the GND end.

[0019] When the control end Switch1 LSCtrl There is current flowing through, and the current generates a voltage through the eighth resistor R1008 to control the MOS tube Q1003 to turn on, and the execution terminal Switch1 LS The current passes through the fifth resistor R1005 and GND to form a loop, that is, conduction. LS After the conduction, the current is generated. The normal current generates a voltage through the seventh resistor R1007 and is fed back to the feedback terminal Switch1. LSMCU monitor.

[0020] On the basis of the above circuit, this embodiment also includes a second triode Q1002 whose C end is electrically connected to the other end of the first resistor R1001, a B end of the second triode Q1002 is electrically connected to one end of a ninth resistor R1009, one end of the ninth resistor R1009 is electrically connected to one end of the second resistor R1002, the other end of the ninth resistor R1009 and the E end of the second triode Q1002 are electrically connected to the GND end respectively, the other end of the second resistor R1002 is electrically connected to the C end of the first triode Q1001, the B end of the first triode Q1001 is electrically connected to one end of the third resistor R1003 and the fourth resistor R1004 respectively, the other end of the fourth resistor R1005 is electrically connected to one end of the fifth resistor R1005, and the E end of the first triode Q1001 is electrically connected to the other end of the third resistor R1003 and the fifth resistor R1005 respectively.

[0021] When the execution end Switch1 LS When the current is too large, the current generates a voltage through the third resistor R1003, causing the first transistor Q1001 to turn on. After the first transistor Q1001 turns on, the current passes through the ninth resistor R1009, and the ninth resistor R1009 generates a voltage to control the second transistor Q1002 to turn on. The control terminal Switch1 LSCtrl The current is turned on through the first resistor R1001, the second transistor Q1002, and the GND terminal. If the current does not pass through the eighth resistor R1008, the voltage-free MOS tube Q1003 is turned off, and the execution terminal Switch1 LS The abnormal current is not conducting, and the voltage generated by the seventh resistor R1007 is fed back to the feedback terminal Switch1. LSMCU monitor.

[0022] One end of the sixth resistor R1006 is electrically connected to one end of the first capacitor C1001, and the other end of the first capacitor C1001 is electrically connected to the GND terminal. The other end of the sixth resistor R1006 is electrically connected to one end of the second capacitor C1002, and the other end of the second capacitor C1002 is electrically connected to the GND terminal.

[0023] A second embodiment of the present invention provides a low-side switch device for overcurrent protection based on the first embodiment, comprising the low-side switch circuit for overcurrent protection described in the first embodiment.

[0024] Although the embodiments of the present invention have been disclosed above, they are not limited to the applications listed in the specification and the embodiments. It can be fully applied to various fields suitable for the present invention. For those familiar with the art, additional modifications can be easily realized. Therefore, without departing from the general concept defined by the claims and equivalent scope, the present invention is not limited to the specific details and the illustrations shown and described here.

Claims

1. A low-side switch circuit for overcurrent protection, characterized in that: Including one end and the control end (Switch1 LSCtrl ) is electrically connected to a first resistor (R1001), the other end of which is electrically connected to the G end of a MOS tube (Q1003), the D end of the MOS tube (Q1003) is electrically connected to one end of a fifth resistor (R1005), and the other end of the fifth resistor (R1005) is electrically connected to the execution end (Switch1 LS ) is electrically connected to one end of the sixth resistor (R1006), and the other end of the sixth resistor (R1006) is electrically connected to the feedback end (Switch1 LSMCU ) and one end of the seventh resistor (R1007) are electrically connected, the S end of the MOS tube (Q1003) and the other end of the seventh resistor (R1007) are electrically connected to the GND end respectively, the G end of the MOS tube (Q1003) is electrically connected to one end of the eighth resistor (R1008), and the other end of the eighth resistor (R1008) is electrically connected to the GND end.

2. The low-side switch circuit for overcurrent protection according to claim 1, characterized in that: The device also includes a second triode (Q1002) whose C terminal is electrically connected to the other end of the first resistor (R1001), whose B terminal is electrically connected to one end of a ninth resistor (R1009), whose one end is electrically connected to one end of the second resistor (R1002), whose other end and the E terminal of the second triode (Q1002) are electrically connected to the GND terminal respectively, and whose second resistor (R1001) is electrically connected to one end of the ninth resistor (R1009). The other end of the first transistor (Q1002) is electrically connected to the C end of the first transistor (Q1001), the B end of the first transistor (Q1001) is electrically connected to one end of the third resistor (R1003) and the fourth resistor (R1004), the other end of the fourth resistor (R1005) is electrically connected to one end of the fifth resistor (R1005), and the E end of the first transistor (Q1001) is electrically connected to the other end of the third resistor (R1003) and the fifth resistor (R1005).

3. A low-side switch circuit for overcurrent protection according to claim 1 or 2, characterized in that: One end of the sixth resistor (R1006) is electrically connected to one end of the first capacitor (C1001), and the other end of the first capacitor (C1001) is electrically connected to the GND end.

4. The low-side switch circuit for overcurrent protection according to claim 3, characterized in that: The other end of the sixth resistor (R1006) is electrically connected to one end of the second capacitor (C1002), and the other end of the second capacitor (C1002) is electrically connected to the GND end.

5. A low-side switch device for overcurrent protection, characterized in that: A low-side switch circuit for overcurrent protection comprising any one of claims 1 to 4.

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