CN-122026883-A - Intelligent low-side power switching circuit applied to vehicle

CN122026883ACN 122026883 ACN122026883 ACN 122026883ACN-122026883-A

Abstract

The application provides an intelligent low-side power switch circuit applied to a vehicle, which is provided with a power interface, a ground interface, a switch interface and an output interface, and comprises a control module, a field effect transistor, a control module and a control module, wherein the control module is connected with the switch interface and the power interface, the field effect transistor is provided with a grid electrode, a drain electrode and a source electrode, the grid electrode is connected with the power interface and the switch interface through the control module, the drain electrode is connected with the output interface, and the source electrode is connected with the ground interface, wherein the control module controls the on and off of the field effect transistor according to a logic level signal of the switch interface so as to control the communication state of the output interface and the ground interface, and the control module realizes protection and detection functions. The application solves the technical problems that the prior large-current low-side control scheme generally adopts a special low-side driving chip and MOSFET, has extremely complex scheme and higher cost, and is difficult to popularize and apply on a large scale.

Inventors

Heng Xueli
ZUO CHENGGANG
YAO LIANGSHUAI
LI YUCHENG
Shang Enhui

Assignees

浙江孚乔图科技有限公司

Dates

Publication Date: 20260512
Application Date: 20260414

Claims (10)

1. An intelligent low-side power switching circuit applied to a vehicle, characterized in that the intelligent low-side power switching circuit is provided with a power interface (11), a ground interface (12), a switching interface (13) and an output interface (14), and the intelligent low-side power switching circuit comprises: The control module is connected with the switch interface (13) and the power interface (11); The field effect transistor is provided with a grid electrode, a drain electrode and a source electrode, the grid electrode is connected with the power interface (11) and the switch interface (13) through the control module, the drain electrode is connected with the output interface (14), and the source electrode is connected with the ground interface (12); The control module controls the on and off of the field effect transistor according to the logic level signal of the switch interface (13), so as to control the communication state of the output interface (14) and the ground interface (12), and the control module realizes the protection and detection functions.
2. The intelligent low-side power switching circuit of claim 1, wherein the control module comprises: The first triode is provided with a first base electrode, a first collector electrode and a first emitter electrode, the first base electrode is connected with the switch interface (13) through a first resistor, and the first emitter electrode is grounded; The second triode is provided with a second base electrode, a second collector electrode and a second emitter electrode, the second base electrode is connected with the first collector electrode through an undervoltage protection unit, the second emitter electrode is connected with the power interface (11), and the second collector electrode is connected with the grid electrode through a seventh resistor.
3. The intelligent low-side power switching circuit of claim 2, wherein the control module further comprises: the fourth triode is provided with a fourth base electrode, a fourth collector electrode and a fourth emitter electrode, the fourth base electrode is connected with the first collector electrode through a charging unit, the fourth emitter electrode is connected with the output interface (14), and the fourth collector electrode is connected with the grid electrode through a short-circuit protection unit.
4. The intelligent low-side power switching circuit according to claim 3, wherein the short-circuit protection unit comprises a fifth transistor and a first diode; the fifth triode is provided with a fifth base electrode, a fifth collector electrode and a fifth emitter electrode, the fifth base electrode is connected to the fourth collector electrode through an eighth resistor and the first diode in sequence, the fifth collector electrode is connected with the grid electrode, and the fifth emitter electrode is grounded; The first diode is provided with a first anode and a first cathode, the first anode is connected with the fourth collector, and the first cathode is connected with the fifth base through the eighth resistor.
5. The intelligent low-side power switching circuit of claim 4, wherein the short-circuit protection unit further comprises: And one end of the ninth resistor is connected with the fifth base electrode, and the other end of the ninth resistor is grounded.
6. The intelligent low-side power switching circuit of claim 3, wherein the charging unit is provided with a first end and a second end, the first end is connected to the first collector, the second end is grounded, and the charging unit comprises: the first resistor is connected with the first capacitor in series, and an adjusting node is arranged between the first resistor and the first capacitor and is connected with the fourth base electrode; The fourth resistor is arranged between the first end and the adjusting node, and the first capacitor is arranged between the adjusting node and the second end.
7. The intelligent low-side power switching circuit of claim 2, wherein the under-voltage protection unit comprises: And the third diode is provided with a third anode and a third cathode, the third anode is connected with the first collector, and the third cathode is connected with the second base through the third resistor.
8. The intelligent low-side power switching circuit of claim 3, wherein the control module further comprises: one end of the second resistor is connected with the first base electrode, and the other end of the second resistor is grounded; one end of the fifth resistor is connected with the second base electrode, and the other end of the fifth resistor is connected with the power interface (11); And one end of the sixth resistor is connected with the fourth base electrode, and the other end of the sixth resistor is connected with the output interface (14).
9. The intelligent low-side power switching circuit of claim 2, wherein the control module further comprises: one end of the NTC resistor is connected with the grid electrode, and the other end of the NTC resistor is grounded; Wherein the NTC resistor is disposed adjacent to the field effect transistor.
10. The intelligent low-side power switching circuit of claim 1, wherein the control module further comprises: The second diode is provided with a second anode and a second cathode, the second anode is grounded, and the second cathode is connected with the grid electrode.

Description

Intelligent low-side power switching circuit applied to vehicle Technical Field The invention relates to the technical field of vehicle electronics and electrics, in particular to an intelligent low-side power switch circuit applied to a vehicle. Background With the rapid development of the automobile industry, the electrification and the intellectualization level of the automobile are continuously improved, higher requirements are put on the reliability, the intellectualization and the cost control of an on-board electric system, and the automobile industry generally adopts electric design of single-wire power supply and negative electrode grounding based on the reasons of cost, reliability and the like, namely a storage battery is directly connected with a generator or DC/DC in parallel, the whole automobile is powered through a power supply positive electrode, and the negative electrode of the storage battery is directly connected with a metal part grounding of the automobile body to form a complete power supply loop. Based on the power supply mode of the vehicle, the high-side power switch in the vehicle electrical system is widely applied, corresponding chip solutions (such as an HSD chip) are also becoming mature, and the HSD chip can replace the traditional relay and the fuse at the same time and serve as an intelligent high-side power switch to supply power to electric equipment or directly control the load of the vehicle, so that the requirements of most vehicle-mounted scenes are met. However, in certain specific applications, there is still an irreplaceable need for low-side power switches, but low-side switching schemes or dedicated chips are currently very few in the industry, especially high-current intelligent low-side power switches are lacking in mature products. In addition, the prior art has at least one problem that the existing high-current low-side control scheme generally adopts a special low-side driving chip and MOSFET (metal oxide semiconductor field effect transistor), but the low-side driving chip generally has no special protection and detection function, and various detection and protection needs to be specially added to be used as an intelligent low-side power switch, so that the scheme is extremely complex, the cost is high, and the large-scale popularization and application are difficult. Disclosure of Invention The invention solves the technical problems that the prior large-current low-side control scheme generally adopts a special low-side driving chip and MOSFET, has extremely complex scheme and higher cost, and is difficult to popularize and apply on a large scale. In order to solve the problems, the invention provides an intelligent low-side power switch circuit applied to a vehicle, which is provided with a power interface, a ground interface, a switch interface and an output interface, and comprises a control module, a control module and a control module, wherein the control module is connected with the switch interface and the power interface; the field effect transistor is provided with a grid electrode, a drain electrode and a source electrode, the grid electrode is connected with a power interface and a switch interface through a control module, the drain electrode is connected with an output interface, and the source electrode is connected with a ground interface, wherein the control module controls the on and off of the field effect transistor according to a logic level signal of the switch interface so as to control the communication state of the output interface and the ground interface, and the protection and detection functions are realized through the control module. Compared with the prior art, the intelligent low-side power switch circuit has the technical effects that on-off control of the field effect transistor is realized based on logic level signals, the control mode is concise and visual, the intelligent low-side power switch circuit can be directly in butt joint with output signals of a vehicle-mounted controller without an additional signal conversion module, the cost is low, the connection difficulty with vehicle-mounted electric equipment is reduced through a standardized power interface, a standardized ground interface, a standardized switch interface and a standardized output interface, the connection difficulty with the vehicle-mounted electric equipment is adapted to various low-side control scenes such as vehicle lights, motors and air conditioners, the intelligent low-side power switch function can be realized at low cost through the control module, and the intelligent functions comprise the functions of overcurrent protection, overheat protection, short-circuit protection, overvoltage protection, undervoltage protection, short-circuit self-locking, automatic recovery after fault release and the like, and the stability, reliability and durability of the low-side power switch under the complex environment of a vehicle are greatly improved.