CN-122003952-A - Step-down circuit, car lamp system and processing method of car lamp control module

CN122003952ACN 122003952 ACN122003952 ACN 122003952ACN-122003952-A

Abstract

The embodiment of the disclosure provides a step-down circuit, a car lamp system and a processing method of a car lamp control module, and relates to the technical field of car lamp control. The voltage-reducing circuit is composed of a driving unit, a current detection module, a first filtering module and a second filtering module, and the current detection module is composed of a current detection resistor, a first current detection filter capacitor and a second current detection filter capacitor. The driving unit adjusts an electric signal output by a direct current power supply of a vehicle to a current value required by a lighting function indicated by the vehicle lamp control instruction based on the vehicle lamp control instruction acquired by the vehicle lamp control module, the adjusted current value is subjected to noise reduction processing by the current detection module, the first filtering module and the second filtering module to obtain a target current value required by the lighting function indicated by the vehicle lamp control instruction, and the first current detection filter capacitor and the second current detection filter capacitor can effectively reduce interference of high-frequency signals on a voltage reduction circuit. Therefore, the electromagnetic compatibility of the car light control module and the accuracy of control time sequence can be improved.

Inventors

GE ZHUANG
ZHOU XIN
WANG LIUJUN
WANG YUNHAO

Assignees

华域视觉科技(常熟)有限公司

Dates

Publication Date: 20260508
Application Date: 20240819

Claims (10)

The voltage reduction circuit is characterized by comprising a driving unit, a current detection module, a first filtering module and a second filtering module, wherein the current detection module comprises a current detection resistor, a first current detection filter capacitor and a second current detection filter capacitor; The input end of the driving unit is used for being connected with a power supply signal and a first control signal from the main control unit, and the first output end of the driving unit is connected with the other end of the current detection resistor, one end of the second current detection filter capacitor and the first input end of the second filter module; The second output end of the driving unit and the first output end of the first filtering module are connected with one end of the current detection resistor and one end of the first current detection filter capacitor, and the other end of the first current detection filter capacitor and the other end of the second current detection filter capacitor are grounded; The third output end of the driving unit is connected with the first input end of the first filtering module, the fourth output end of the driving unit is connected with the second input end of the first filtering module, and the second output end of the first filtering module is grounded; The second input end of the second filtering module is connected with the output end of the boost driving unit, the first output end of the second filtering module is connected with the input end of the luminous matrix management unit, and the second output end of the second filtering module is grounded.
The voltage reduction circuit according to claim 1, wherein a capacitance of the first current detection filter capacitor is 60pF to 70pF.
The voltage reduction circuit according to claim 1, wherein a capacitance of the second current detection filter capacitor is 40pF to 50pF.
The buck circuit according to claim 1, wherein the first filter module includes a first resistor, a first capacitor, a first inductor, and a first reverse diode; One end of the first resistor is connected with the third output end of the driving unit, the other end of the first resistor is connected with one end of the first capacitor, and the other end of the first capacitor is respectively connected with the fourth output end of the driving unit, one end of the first inductor and the input end of the first reverse diode; The output end of the first reverse diode is grounded, and the other end of the first inductor is connected with the current detection resistor and one end of the first current detection filter capacitor.
The voltage reduction circuit according to claim 4, wherein the first resistor has a resistance value of 5 Ω to 15 Ω.
The buck circuit according to claim 1, wherein the second filter module includes a second resistor, a second capacitor, a third capacitor, a fourth capacitor, a fifth capacitor, a second inductor, a second reverse diode, and a third reverse diode; One end of the second capacitor is respectively connected with the other end of the current detection resistor, one end of the second current detection filter capacitor, the first output end of the driving unit and one end of the third capacitor, one end of the third capacitor is also connected with the output end of the second reverse diode and one end of the second inductor, the input end of the second reverse diode is connected with the output end of the boost driving unit, and the other end of the second capacitor, the other end of the third capacitor and the output end of the third reverse diode are all grounded; The input end of the third reverse diode is respectively connected with one end of the second inductor and one end of the fourth capacitor, the other end of the second inductor is respectively connected with the other end of the fourth capacitor, one end of the second resistor, one end of the fifth capacitor and the input end of the luminous matrix management unit, and the other end of the fifth capacitor and the other end of the second resistor are grounded.
The voltage reduction circuit according to claim 6, wherein a capacitance of the third capacitor is 1pF to 4pF.
A car lamp system is characterized by comprising a car lamp control module, a light-emitting management module, a light-emitting module and a low-side switch module; the car light control module comprises a power management unit, a bus transceiver unit, a main control unit, a boost driving unit and a plurality of step-down circuits as set forth in any one of claims 1-7; The luminous management module comprises a plurality of luminous matrix management units, a plurality of voltage reduction circuits and a main control unit, wherein each luminous matrix management unit is connected with each voltage reduction circuit in a one-to-one correspondence manner, and at least one luminous matrix management unit is connected with the main control unit; the light-emitting module comprises a plurality of light-emitting modules, each light-emitting module is connected with each light-emitting matrix management unit in a one-to-one correspondence manner, and each light-emitting module is connected with the low-side switch module.
A method of processing a vehicle lamp control module, as applied to the main control unit of claim 8, the method comprising: receiving a car lamp control instruction sent by a bus receiving and transmitting unit; generating a target control time sequence according to the car lamp control instruction; And sending corresponding first control signals to each voltage reduction circuit according to the target control time sequence, and sending second control signals to the low-side switch module, so that the voltage reduction circuit outputs corresponding voltage values to the corresponding luminous matrix management unit under the action of the first control signals, and the low-side switch module is turned on or turned off under the action of the second control signals.
The method of processing a vehicle lamp control module of claim 9, further comprising: Determining a target luminous matrix management unit according to the car light control instruction; and sending a third control signal to the target luminous matrix management unit so that the target luminous matrix management unit controls the on-off of each control port on the target luminous matrix management unit under the action of the third control signal.

Description

Step-down circuit, car lamp system and processing method of car lamp control module Technical Field The disclosure relates to the technical field of vehicle lamp control, in particular to a step-down circuit, a vehicle lamp system and a processing method of a vehicle lamp control module. Background The step-down circuit is mainly used for reducing the voltage of the direct-current power supply to a voltage threshold value required by a load, and is widely applied to a car lamp control module. However, the performance of the step-down circuit will directly affect the electromagnetic compatibility test result of the lamp control module. Therefore, a step-down circuit with good performance and high safety is needed to improve the electromagnetic compatibility of the lamp control module. In the related art, the dimming function of a general car lamp is realized by a circuit consisting of a voltage reducing circuit and a low-side switch in a car lamp control module, wherein the input end of the voltage reducing circuit is connected with a direct current power supply in a car and a whole car controller, the output end of the voltage reducing circuit is connected with the input end of the car lamp, and the low-side switch is used for adding the car lamp into a grounding end. The voltage reducing circuit reduces the voltage of a direct current power supply in the car lamp system to a voltage threshold level meeting the dimming function of the car lamp, and the low-side switch is turned on through the grounding detection control circuit so as to complete dimming control of the car lamp. However, the filter capacitance margin in the step-down circuit is limited, affecting the electromagnetic compatibility test result of the lamp control module. In addition, the control time sequence accuracy of the voltage reducing circuit and the low-side switch is poor, and the voltage reducing chip in the voltage reducing circuit is easy to damage. The information disclosed in this background section is only for enhancement of understanding of the general background of the disclosure and is not to be taken as an admission or any form of suggestion that this information forms the prior art that is well known to a person skilled in the art. Disclosure of Invention The object of the present disclosure includes, for example, providing a step-down circuit, a lamp system, and a processing method of a lamp control module, which can improve the shortcomings of the related art, can improve the electromagnetic compatibility of the lamp system, and can improve the accuracy of the control timing of the step-down circuit and the low-side switch. Embodiments of the present disclosure may be implemented as follows: the embodiment of the disclosure provides a voltage reduction circuit, which comprises a driving unit, a current detection module, a first filtering module and a second filtering module, wherein the current detection module comprises a current detection resistor, a first current detection filter capacitor and a second current detection filter capacitor; The input end of the driving unit is used for being connected with a power supply signal and a first control signal from the main control unit, and the first output end of the driving unit is connected with the other end of the current detection resistor, one end of the second current detection filter capacitor and the first input end of the second filter module; The second output end of the driving unit and the first output end of the first filtering module are connected with one end of the current detection resistor and one end of the first current detection filter capacitor, and the other end of the first current detection filter capacitor and the other end of the second current detection filter capacitor are grounded; the third output end of the driving unit is connected with the first input end of the first filtering module, the fourth output end of the driving unit is connected with the second input end of the first filtering module, and the second output end of the first filtering module is grounded; The second input end of the second filtering module is connected with the output end of the boost driving unit, the first output end of the second filtering module is connected with the input end of the luminous matrix management unit, and the second output end of the second filtering module is grounded. Optionally, the capacitance of the first current-detecting filter capacitor is 60pF to 70pF. Optionally, the capacitance of the second current-detecting filter capacitor is 40pF to 50pF. Optionally, the first filtering module comprises a first resistor, a first capacitor, a first inductor and a first reverse diode; one end of the first resistor is connected with the third output end of the driving unit, the other end of the first resistor is connected with one end of the first capacitor, and the other end of the first capacitor is respectively connected with the fourth output end of