Multi-channel constant current source circuit device

Abstract

The utility model discloses a multichannel constant current source circuit device, comprising an MCU unit, an integrated constant current source unit and a plurality of voltage and current detection modules, the MCU unit comprises a serial port sending end and a serial port receiving end, the input end of the integrated constant current source unit is respectively connected with the serial port sending end and an input power supply and is used for receiving a PWM signal issued by the MCU unit, and the voltage and current detection modules are connected with the input end of the integrated constant current source unit. Therefore, the integrated constant current source unit is powered on and enabled. The output end of the integrated constant current source unit is respectively connected with the plurality of voltage and current detection modules, and the voltage and current detection modules are connected with the load end to form a plurality of constant current source outputs. The integrated constant current source unit comprises a DCDC boost power supply module and a ground short circuit detection and constant current source module. And each voltage and current detection module is connected with the serial port receiving end and is used for transmitting voltage and current information to the MCU unit. By arranging the integrated constant current source unit, one DAC module, one ADC module and one DCDC boost-buck module are saved, meanwhile, the PCB layout is optimized, and the circuit hardware cost and the software development cost are reduced.

Description

TECHNICAL FIELD

[0001] The utility model relates to constant current source circuit technical field, concretely relates to a kind of multi-channel constant current source circuit device. BACKGROUND

[0002] The multi-channel constant current source circuit device in prior art is mainly composed of MCU main control module, DAC module and ADC module, DCDC adjustable step-down module and DCDC adjustable step-up module, multiple current voltage sampling modules and multiple constant current source control modules etc..Main working state is the output voltage of DCDC step-up circuit, which is controlled voltage output by MCU main control module through DAC module, and the output signal of MCU main control module is used to control the constant current source module to output current size.Voltage current data is collected by voltage current sampling module, and fed back to ADC module, and then adjusted to the current output of constant current source after output to MCU main control, and the simplified circuit module structure is as shown in the description Figure 1 As each output channel is designed with control module and DCDC step-up and step-down module, there are more electronic components, larger PCB area occupation, and performance redundancy, higher cost and no advantage. INVENTION CONTENTS

[0003] To overcome the above-mentioned shortcomings, the purpose of the utility model is to provide a kind of multi-channel constant current source circuit device to solve the problems caused in the above background technology.

[0004] To achieve the above purpose, the utility model adopts the technical scheme of a kind of multi-channel constant current source circuit device, including MCU unit, integrated constant current source unit and multiple voltage current detection modules, wherein:

[0005] The MCU unit includes serial port sending end and serial port receiving end, the input end of the integrated constant current source unit is connected with the serial port sending end and input power respectively, for receiving the PWM signal issued by the MCU unit, to enable the integrated constant current source unit to power on.

[0006] The output end of the integrated constant current source unit is connected with the multiple voltage current detection modules respectively, and the voltage current detection modules are connected with load end to form multiple constant current source outputs.The integrated constant current source unit includes DCDC step-up power module, ground short circuit detection and constant current source module.Each voltage current detection module is connected with the serial port receiving end, for transmitting voltage current information to the MCU unit.

[0007] Further, the constant current source module comprises a voltage reduction module U3, a first inductor L1, a first diode D1, a second resistor R3, a fourth resistor R5 and a first MOS tube Q1. One end of the first inductor L1 is connected to the anode of the first diode D1, the other end of the first inductor L1 is a power input end, and the cathode of the first diode D1 is a first output end. The gate of the first MOS tube Q1 is connected to one end of the second resistor R3 connected to the voltage reduction module U3, the drain is connected to one end of the fourth resistor R5 connected to the voltage reduction module U3, and the source is connected to the node between the first inductor L1 and the first diode.

[0008] Further, the constant current source module further comprises a second MOS tube Q2, a third resistor R4 and a first capacitor C1. The source of the second MOS tube Q2 is connected to the node between the fourth resistor R5 and the first MOS tube Q1, the gate is connected to the node between the second resistor R3 and the voltage reduction module U3 through the third resistor R4, and the drain is connected to the node between the first inductor L1 and the first diode. The other end of the voltage reduction module U3 is connected in series with the first capacitor C1 to ground.

[0009] Further, the constant current source module further comprises an LED open short circuit protection circuit and a fifth resistor R6, the LED open short circuit protection circuit is connected to one end of the voltage reduction module U3, and one end of the fifth resistor R6 is connected to the node between the LED open short circuit protection circuit and the voltage reduction module U3, and the other end is grounded.

[0010] Further, the voltage reduction module U3 is internally provided with a linear voltage stabilizer for reducing the input voltage of the power input end to 6V to supply power to the internal circuit.

[0011] Further, each voltage and current detection module comprises a sampling resistor R1 and an integrated detection module U2. The two ends of the sampling resistor R1 are respectively a cathode input current end and a second output end. The integrated detection module U2 is connected in parallel to the two ends of the sampling resistor R1 and comprises a current sensor and an analog-to-digital converter for detecting the current and voltage values of the sampling resistor R1.

[0012] Further, the integrated detection module U2 is connected to the MCU unit through an I2C bus for transmitting the current and voltage values to the MCU unit.

[0013] Further, the first MOS tube Q1 and the second MOS tube Q2 are both N-type MOS tubes.

[0014] Further, the multi-channel constant current source circuit device further comprises a host computer, which is connected in communication with the MCU unit for reading and displaying the voltage and current information.

[0015] Further, the multi-channel constant current source circuit device further comprises a plurality of short circuit detection modules, which are arranged in one-to-one correspondence with the plurality of voltage and current detection modules and are in communication connection with the MCU unit.

[0016] The multi-channel constant current source circuit device has the advantages and beneficial effects that:

[0017] The integrated constant current source module is used to optimize the circuit structure, reduce the complexity of the circuit, and reduce the number of constant current source modules, so that the multi-channel constant current source design is realized while the maximum power is ensured. BRIEF DESCRIPTION OF DRAWINGS

[0018] Figure 1 A simplified circuit module diagram of the multi-channel constant current source circuit device in the prior art is shown.

[0019] Figure 2 A circuit principle structure schematic diagram of one embodiment of the multi-channel constant current source circuit device is shown.

[0020] Figure 3 A circuit diagram of the constant current source module of one embodiment of the multi-channel constant current source circuit device is shown.

[0021] Figure 4 A circuit diagram of the voltage and current detection module of one embodiment of the multi-channel constant current source circuit device is shown. DETAILED DESCRIPTION

[0022] The preferred embodiments of the present application will be described in detail below with reference to the accompanying drawings, so that the advantages and features of the present application can be more easily understood by those skilled in the art, and the protection scope of the present application is more clearly defined.

[0023] REFERENCE Figures 2 to 4 , Figure 2 A circuit principle structure schematic diagram of the multi-channel constant current source circuit device is shown. Figure 3 A circuit diagram of the constant current source module of one embodiment of the multi-channel constant current source circuit device is shown. Figure 4 A circuit diagram of the voltage and current detection module of one embodiment of the multi-channel constant current source circuit device is shown.

[0024] As Figures 2 to 4As shown, the technical scheme provided by the application is a multi-channel constant current source circuit device, which comprises an MCU unit, an integrated constant current source unit and a plurality of voltage and current detection modules.

[0025] The MCU unit comprises a serial port sending end and a serial port receiving end, the input end of the integrated constant current source unit is connected with the serial port sending end and an input power supply, and is used to receive a PWM signal issued by the MCU unit, so as to enable the integrated constant current source unit.

[0026] The output end of the integrated constant current source unit is connected with the plurality of voltage and current detection modules, the voltage and current detection modules are connected with a load end, so as to form a plurality of constant current source outputs. The integrated constant current source unit comprises a DCDC boost power supply module, a ground short circuit detection module and a constant current source module. Each voltage and current detection module is connected with the serial port receiving end, and is used to transmit voltage and current information to the MCU unit.

[0027] The MCU unit of the multi-channel constant current source circuit device provided by the application is mainly composed of a microprocessor chip, and is used to issue a PWM signal for controlling the output current size of the constant current source module, enabling the constant current source module, and detecting the return value of the voltage and current module. The integrated constant current source unit mainly integrates the DCDC boost power supply module, the ground short circuit detection module and the constant current source module together, so that a DAC module, an ADC module and a DCDC boost and buck module can be saved, the PCB layout can be optimized, the circuit hardware cost and the software development cost can be reduced. In addition, the traditional constant current source can only output a fixed (constant current), and if a string of lamp strings or resistors is damaged, the remaining circuit will be burned out and cannot protect the components on other circuits. In the present application, the multi-channel constant current source is adopted, which does not interfere with each other, so as to ensure the normal operation of the circuit.

[0028] In some embodiments, with reference to Figures 2 to 4 , the constant current source module comprises a buck module U3, a first inductor L1, a first diode D1, a second resistor R3, a fourth resistor R5 and a first MOS tube Q1. One end of the first inductor L1 is connected with the anode end of the first diode D1, the other end of the first inductor L1 is a power input end VBL-IN, and the cathode end of the first diode D1 is a first output end VLEDA-I. The gate of the first MOS tube Q1 is connected with one end of the second resistor R3 connected with the buck module U3, the drain is connected with one end of the fourth resistor R5 connected with the buck module U3, and the source is connected with a node between the first inductor L1 and the first diode.

[0029] The constant current source module further comprises a second MOS transistor Q2, a third resistor R4 and a first capacitor C1. The source of the second MOS transistor Q2 is connected to a node between the fourth resistor R5 and the first MOS transistor Q1, the gate is connected to a node between the third resistor R4, the second resistor R3 and the voltage reduction module U3, and the drain is connected to a node between the first inductor L1 and the first diode. The other end of the voltage reduction module U3 is connected to the first capacitor C1 in series and to ground.

[0030] The constant current source module further comprises an LED open short circuit protection circuit LEDK0 and a fifth resistor R6. The LED open short circuit protection circuit is connected to one end of the voltage reduction module U3, one end of the fifth resistor R6 is connected to a node between the LED open short circuit protection circuit and the voltage reduction module U3, and the other end is connected to ground.

[0031] By way of example, the input power VBL-IN is input through the first inductor L1. In the case where the voltage reduction module U3 is not working, the input and output of this circuit are equal. The first capacitor C1 is set for internal voltage filtering, and a resistor is connected in series at the gate of the MOS transistor to prevent oscillation caused by too fast voltage on the gate. The constant current source module forms overcurrent protection, output short circuit protection, diode open circuit and short circuit protection, LED open short circuit protection through the set components, and automatically adjusts the voltage size according to the size of the load and the set current size during normal power-on.

[0032] In some embodiments, with reference to Figures 2 to 4 The voltage reduction module U3 is internally provided with a linear voltage regulator for reducing the input voltage of the power input end VBL-IN to 6V to supply power to the internal circuit.

[0033] By way of example, the linear voltage regulator generally has a fast transient response, can quickly adapt to load changes, thereby maintaining a stable output voltage, and the design of the linear voltage regulator is relatively simple, without the need for complex circuit configuration, which helps to simplify the overall design and reduce the number of components.

[0034] In some embodiments, with reference to Figures 2 to 4 Each voltage and current detection module comprises a sampling resistor R1 and an integrated detection module U2. The two ends of the sampling resistor R1 are respectively a cathode input current end VLED0 and a second output end LED0. The integrated detection module U2 is connected in parallel to the two ends of the sampling resistor R1 and comprises a current sensor and an analog-to-digital converter for detecting the current and voltage values of the sampling resistor R1.

[0035] Exemplarily, the integrated detection module U2 is built-in with a current sensor, which is based on Hall effect or resistive sensor. When the current passes through the sampling resistor R1 and then through the input pin of the chip, the current sensor compares the voltage on the two pins, and then generates a voltage signal proportional to the current. The current sensor internally converts the current and voltage signals into digital signals. The integrated detection module U2 also contains a built-in analog-to-digital converter (ADC) for converting analog signals into digital form. The analog-to-digital converter divides the continuous analog signal into discrete digital levels, outputs the corresponding digital value, and sends it to the digital signal processing part for processing such as amplification, filtering and calibration to produce accurate current and voltage measurement results.

[0036] In some embodiments, the integrated detection module U2 is connected with the MCU unit through the I2C bus for transmitting the current and voltage values to the MCU unit.

[0037] Exemplarily, the I2C bus is a synchronous serial communication protocol that only requires two lines (data line SDA and clock line SCL) for communication, and the data transmission is more efficient in the case of multiple device connection. After the data results output by the integrated detection module U2 are read by the MCU unit, the VLED0 voltage value can be obtained by calculation, and the value is uploaded to the host computer simultaneously, so that the read current and voltage values can be displayed on the host computer.

[0038] In some embodiments, the first MOS tube Q1 and the second MOS tube Q2 are both N-type MOS tubes.

[0039] In some embodiments, referring to Figures 2 to 4 The multi-channel constant current source circuit device further includes a host computer, which is connected in communication with the MCU unit for reading and displaying the voltage and current information.

[0040] Exemplarily, the MCU unit is read by the host computer to display the read current and voltage values.

[0041] In some embodiments, referring to Figures 2 to 4 The multi-channel constant current source circuit device further includes a plurality of short circuit detection modules, which are one-to-one corresponding to the plurality of voltage and current detection modules and are connected in communication with the MCU unit.

[0042] Exemplarily, the short circuit detection module can timely detect and respond to the short circuit condition, prevent the circuit from being damaged, and improve the safety of the whole system. The communication connection of the short circuit detection module and the MCU unit enables the voltage and current information to be quickly and accurately transmitted to the MCU unit, so that the system can make a quick response. Specifically, the short circuit detection module can use a shunt resistor to detect. A detection resistor Roc is connected in series with the MOSFET source of the power supply loop. When the current flows through the resistor Roc, a voltage Voc is generated. If the detected voltage is greater than the threshold voltage VOCTH of the logic gate circuit, a short circuit signal OC Fault will be generated, and at the same time, the driver will close the OUT output. The short circuit detection module can also use desaturation detection. The essence of desaturation detection is voltage detection. When the device is short-circuited, the voltage between the drain and the source of the device will abnormally rise. Therefore, the drain-source voltage of the device when it is normally turned on and when it is short-circuited can be compared as the basis for short-circuit judgment.

[0043] The above embodiments are only for illustrating the technical concept and characteristics of the present application, and the purpose is to enable those skilled in the art to understand the content of the present application and implement it, and cannot limit the protection scope of the present application. Any equivalent changes or modifications made according to the spirit and essence of the present application shall be covered within the protection scope of the present application.

Claims

1. A multi-channel constant current source circuit arrangement, characterized by, The application relates to a constant current source module, which comprises an MCU unit, an integrated constant current source unit and a plurality of voltage and current detection modules. The MCU unit comprises a serial port sending end and a serial port receiving end, the input end of the integrated constant current source unit is connected with the serial port sending end and an input power supply respectively, and the integrated constant current source unit is used for receiving a PWM signal issued by the MCU unit to enable the integrated constant current source unit to be powered on; The output end of the integrated constant current source unit is connected with the plurality of voltage and current detection modules respectively, the voltage and current detection modules are connected with a load end to form a plurality of constant current source outputs, the integrated constant current source unit comprises a DCDC voltage boosting power supply module, a ground short circuit detection module and a constant current source module, and each voltage and current detection module is connected with the serial port receiving end and used for transmitting voltage and current information to the MCU unit.

2. The multi-channel constant current source circuit arrangement of claim 1, wherein, The constant current source module comprises a voltage reduction module U3, a first inductor L1, a first diode D1, a second resistor R3, a fourth resistor R5 and a first MOS tube Q1, one end of the first inductor L1 is connected with the anode end of the first diode D1, the other end of the first inductor L1 is a power input end, the cathode end of the first diode D1 is a first output end, the gate of the first MOS tube Q1 is connected with one end of the second resistor R3 connected with the voltage reduction module U3, the drain is connected with one end of the fourth resistor R5 connected with the voltage reduction module U3, and the source is connected with a node between the first inductor L1 and the first diode.

3. The multi-channel constant current source circuit arrangement of claim 2, wherein, The constant current source module further comprises a second MOS tube Q2, a third resistor R4 and a first capacitor C1, the source of the second MOS tube Q2 is connected with a node between the fourth resistor R5 and the first MOS tube Q1, the gate is connected with a node between the third resistor R4 connected with the second resistor R3 and the voltage reduction module U3, and the drain is connected with a node between the first inductor L1 and the first diode; the other end of the voltage reduction module U3 is connected with the first capacitor C1 in series and grounded.

4. The multi-channel constant current source circuit arrangement of claim 2, wherein, The constant current source module further comprises an LED open short circuit protection circuit and a fifth resistor R6, one end of the LED open short circuit protection circuit is connected with one end of the voltage reduction module U3, one end of the fifth resistor R6 is connected with the LED open short circuit protection circuit and the voltage reduction module U3, and the other end is grounded.

5. The multi-channel constant current source circuit arrangement of claim 2, wherein, The voltage reduction module U3 is internally provided with a linear voltage stabilizer, which is used for reducing the input voltage of the power input end VBL-IN to 6V to supply power to internal circuits.

6. The multi-channel constant current source circuit arrangement of claim 1, wherein, Each voltage and current detection module comprises a sampling resistor R1 and an integrated detection module U2, two ends of the sampling resistor R1 are respectively a cathode input current end and a second output end, the integrated detection module U2 is connected in parallel with the two ends of the sampling resistor R1 and comprises a current sensor and an analog-digital converter, and is used for detecting the current and voltage values of the sampling resistor R1.

7. The multi-channel constant current source circuit arrangement of claim 6, wherein, The integrated detection module U2 is connected with the MCU unit through an I2C bus communication connection and is used for transmitting the current and voltage values to the MCU unit.

8. The multi-channel constant current source circuit arrangement of claim 3, wherein, The first MOS tube Q1 and the second MOS tube Q2 are both N-type MOS tubes.

9. The multi-channel constant current source circuit arrangement of claim 1, wherein, The application further comprises a host computer, which is in communication connection with the MCU unit and is used for reading and displaying the voltage and current information.

10. The multi-channel constant current source circuit arrangement of claim 1, wherein, The application further comprises a plurality of short-circuit detection modules, which are arranged in one-to-one correspondence with the plurality of voltage and current detection modules and are in communication connection with the MCU unit.

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