A constant current driving circuit for a high current pumping laser

Abstract

The application relates to the technical field of pump laser driving, and particularly discloses a large-current pump laser constant-current driving circuit, which comprises a single-chip microcomputer, a current detection resistor, a differential amplifier, a comparator, a PWM controller and a MOS tube; the comparator is connected with the PWM controller, the differential amplifier and the single-chip microcomputer respectively; the PWM controller, the MOS tube and the current detection resistor are sequentially connected; the current detection resistor is connected with the differential amplifier and the pump laser respectively; the single-chip microcomputer provides a set current; the current detection resistor detects the working current of the pump laser; the differential amplifier is used for amplifying the working current; the comparator is used for comparing the amplified working current with the set current and then outputting a feedback voltage to the PWM controller; and the PWM controller adjusts the on-duty ratio of the MOS tube according to the feedback voltage, so as to adjust the working current of the pump laser. The application can realize the automatic constant-current working of the pump laser, the hardware circuit can automatically keep the constant current, and the control is simple and efficient.

Description

Technical Field

[0001] This invention relates to the field of pump laser driving technology, and more specifically, to a constant current driving circuit for a high-current pump laser. Background Technology

[0002] In the existing technology, the constant current drive circuit of pump laser is mainly a linear drive method. This method has low conversion efficiency, and the heat generation is more serious, especially when operating at high current. The current adjustment uses an adjustable resistor, which reduces the stability of the system and may even damage the pump laser. Summary of the Invention

[0003] To address the shortcomings of existing technologies, this invention provides a constant current drive circuit for a high-current pumped laser, which solves the problem that linear drive methods in existing technologies reduce system stability and may even damage the pumped laser.

[0004] As a first aspect of the present invention, a constant current driving circuit for a high-current pumped laser is provided, comprising a microcontroller, a current sensing resistor, a differential amplifier, a comparator, a PWM controller, and a MOSFET. The comparator is connected to the PWM controller, the differential amplifier, and the microcontroller, respectively. The PWM controller, the MOSFET, and the current sensing resistor are connected in sequence. The current sensing resistor is also connected to the differential amplifier and the pumped laser, respectively. The microcontroller is used to provide the set current; The current sensing resistor is used to detect the operating current of the pump laser; The differential amplifier is used to amplify the detected operating current of the pump laser; The comparator is used to compare the amplified operating current of the pump laser with the set current, and output a feedback voltage to the PWM controller based on the comparison result; The PWM controller is used to adjust the duty cycle of the MOSFET based on the feedback voltage, thereby adjusting the output current of the current sensing resistor to adjust the operating current of the pump laser and realize the automatic constant current operation of the pump laser.

[0005] Furthermore, it also includes an inductor L1, the MOSFETs include a first MOSFET Q1 and a second MOSFET Q2, the PWM controller includes a PWM controller chip U1, the current sensing resistor includes a first resistor R1, the differential amplifier includes a second resistor R2, a third resistor R3, a fourth resistor R4, a fifth resistor R5 and a first operational amplifier U2, and the comparator includes a sixth resistor R6, a seventh resistor R7 and a second operational amplifier U3.

[0006] Furthermore, the TG port of the PWM controller chip U1 is connected to the gate of the first MOSFET Q1, the drain of the first MOSFET Q1 is connected to the power supply VCC, the BG port of the PWM controller chip U1 is connected to the gate of the second MOSFET Q2, the source of the second MOSFET Q2 is grounded, and the PHASE port of the PWM controller chip U1 is connected to the source of the first MOSFET Q1, the drain of the second MOSFET Q2, and one end of the inductor L1.

[0007] Furthermore, the other end of the inductor L1 is connected to one end of the first resistor R1, one end of the fourth resistor R4, and one end of the sixth resistor R6, respectively. The other end of the first resistor R1 is connected to one end of the second resistor R2 and the positive terminal of the pump laser, and the negative terminal of the pump laser is grounded. The other end of the second resistor R2 is connected to one end of the third resistor R3 and the inverting input terminal of the first operational amplifier U2, respectively. The other end of the fourth resistor R4 is connected to one end of the fifth resistor R5 and the positive input terminal of the first operational amplifier U2, respectively. The other end of the fifth resistor R5 is grounded. The output terminal of the first operational amplifier U2 is connected to the other end of the third resistor R3 and the positive input terminal of the second operational amplifier U3, respectively.

[0008] Furthermore, the inverting input terminal of the second operational amplifier U3 is connected to the DA port of the microcontroller U4, one end of the seventh resistor R7 is connected to the output terminal of the second operational amplifier U3, and the other end of the seventh resistor R7 is connected to the other end of the sixth resistor R6 and the FB port of the PWM controller chip U1.

[0009] The constant current drive circuit for a high-current pumped laser provided by this invention has the following advantages: A microcontroller sets the current value, a current sensing resistor detects the operating current of the pumped laser, the operating current of the pumped laser is amplified by a differential amplifier and then input to a comparator for comparison with the set current value provided by the microcontroller. The comparator outputs a feedback voltage to the PWM controller, which adjusts the duty cycle of the MOSFET to achieve automatic adjustment of the pumped laser's high-current operation. The hardware circuit automatically maintains constant current, resulting in simple and efficient control, high conversion efficiency, low heat generation during high-current operation, low hardware failure rate, high stability, and a wide range of PWM controller chips and MOSFETs available for easy procurement. Attached Figure Description

[0010] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used together with the following detailed description to explain the invention, but do not constitute a limitation thereof.

[0011] Figure 1The system block diagram of the constant current drive circuit for a high-current pumped laser provided by the present invention is shown.

[0012] Figure 2 This is a schematic diagram of the constant current drive circuit for a high-current pumped laser provided by the present invention. Detailed Implementation

[0013] To further illustrate the technical means and effects adopted by the present invention to achieve its intended purpose, the following, in conjunction with the accompanying drawings and preferred embodiments, details the specific implementation, structure, features, and effects of a high-current pumped laser constant current driving circuit proposed according to the present invention. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the protection scope of the present invention.

[0014] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate for the embodiments of the invention described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0015] In explaining this invention, it should be noted that the terms "installation," "connection," and "linking" should be interpreted broadly unless otherwise specified. For example, a connection can be a fixed connection, a connection through a special interface, or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0016] This embodiment provides a constant current drive circuit for a high-current pumped laser, such as... Figure 1 As shown, the constant current drive circuit of the high current pump laser includes a microcontroller, a current sensing resistor, a differential amplifier, a comparator, a PWM controller, and a MOSFET. The comparator is connected to the PWM controller, the differential amplifier, and the microcontroller. The PWM controller, the MOSFET, and the current sensing resistor are connected in sequence. The current sensing resistor is also connected to the differential amplifier and the pump laser. The microcontroller is used to provide the set current; The current sensing resistor is used to detect the operating current of the pump laser; The differential amplifier is used to amplify the detected operating current of the pump laser; The comparator is used to compare the amplified operating current of the pump laser with the set current, and output a feedback voltage to the PWM controller based on the comparison result; The PWM controller is used to adjust the duty cycle of the MOSFET based on the feedback voltage, thereby adjusting the output current of the current sensing resistor to adjust the operating current of the pump laser and realize the automatic constant current operation of the pump laser.

[0017] This invention provides a constant current drive circuit for a high-current pumped laser. A microcontroller sets the current, and a current-sensing resistor detects the operating current of the pumped laser. The operating current is amplified by a differential amplifier and then input to a comparator for comparison with the current value set by the microcontroller. The comparator outputs a feedback voltage to a PWM controller, which adjusts the duty cycle of the MOSFET to achieve automatic adjustment for high-current operation of the pumped laser. This circuit offers high conversion efficiency, low heat generation during high-current operation, low hardware failure rate, high stability, automatic constant current maintenance, simple and efficient control, and a wide range of readily available PWM controller chips and MOSFETs.

[0018] Preferably, such as Figure 2 As shown, it also includes an inductor L1, the MOSFETs include a first MOSFET Q1 and a second MOSFET Q2, the PWM controller includes a PWM controller chip U1, the current sensing resistor includes a first resistor R1, the differential amplifier includes a second resistor R2, a third resistor R3, a fourth resistor R4, a fifth resistor R5 and a first operational amplifier U2, and the comparator includes a sixth resistor R6, a seventh resistor R7 and a second operational amplifier U3.

[0019] Specifically, the TG port of the PWM controller chip U1 is connected to the gate of the first MOSFET Q1, the drain of the first MOSFET Q1 is connected to the power supply VCC, the BG port of the PWM controller chip U1 is connected to the gate of the second MOSFET Q2, the source of the second MOSFET Q2 is grounded, and the PHASE port of the PWM controller chip U1 is connected to the source of the first MOSFET Q1, the drain of the second MOSFET Q2, and one end of the inductor L1.

[0020] Specifically, the other end of the inductor L1 is connected to one end of the first resistor R1, one end of the fourth resistor R4, and one end of the sixth resistor R6. The other end of the first resistor R1 is connected to one end of the second resistor R2 and the positive terminal of the pump laser. The negative terminal of the pump laser is grounded. The other end of the second resistor R2 is connected to one end of the third resistor R3 and the inverting input terminal of the first operational amplifier U2. The other end of the fourth resistor R4 is connected to one end of the fifth resistor R5 and the positive input terminal of the first operational amplifier U2. The other end of the fifth resistor R5 is grounded. The output terminal of the first operational amplifier U2 is connected to the other end of the third resistor R3 and the positive input terminal of the second operational amplifier U3.

[0021] Specifically, the inverting input terminal of the second operational amplifier U3 is connected to the DA port of the microcontroller U4, one end of the seventh resistor R7 is connected to the output terminal of the second operational amplifier U3, and the other end of the seventh resistor R7 is connected to the other end of the sixth resistor R6 and the FB port of the PWM controller chip U1.

[0022] In this embodiment, the high-current pump laser constant current drive circuit described above is used to drive the pump laser.

[0023] The present invention provides a constant current driving circuit for a high-current pumped laser, the working principle of which is as follows: The current value is set using microcontroller U4. The set current value is output from the DA port of microcontroller U4 to the inverting input of the second operational amplifier U3. The operating current value of the pump laser is detected by the current sensing resistor R1. The operating current of the pump laser is amplified by the first operational amplifier U2 and then input to the non-inverting input of the second operational amplifier U3. The second operational amplifier U3 compares the amplified operating current of the pump laser with the set current value provided by microcontroller U4. The output of the second operational amplifier U3 outputs a feedback voltage to the FB port of the PWM controller. The PWM controller adjusts the duty cycle of the first MOSFET Q1 and the second MOSFET Q2 through the TG port and BG port respectively according to the feedback voltage, thereby adjusting the output current of the current sensing resistor R1 to adjust the operating current of the pump laser and realize the automatic constant current operation of the pump laser.

[0024] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some modifications or alterations to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the present invention. Any simple modifications, equivalent changes, and alterations made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the scope of the present invention.

Claims

1. A constant current drive circuit for a high-current pumped laser, characterized in that, It includes a microcontroller, a current sensing resistor, a differential amplifier, a comparator, a PWM controller, and a MOSFET. The comparator is connected to the PWM controller, the differential amplifier, and the microcontroller. The PWM controller, the MOSFET, and the current sensing resistor are connected in sequence. The current sensing resistor is also connected to the differential amplifier and the pump laser. The microcontroller is used to provide the set current; The current sensing resistor is used to detect the operating current of the pump laser; The differential amplifier is used to amplify the detected operating current of the pump laser; The comparator is used to compare the amplified operating current of the pump laser with the set current, and output a feedback voltage to the PWM controller based on the comparison result; The PWM controller is used to adjust the duty cycle of the MOSFET based on the feedback voltage, thereby adjusting the output current of the current sensing resistor to adjust the operating current of the pump laser and realize the automatic constant current operation of the pump laser. It also includes an inductor L1, the MOSFETs include a first MOSFET Q1 and a second MOSFET Q2, the PWM controller includes a PWM controller chip U1, the current sensing resistor includes a first resistor R1, the differential amplifier includes a second resistor R2, a third resistor R3, a fourth resistor R4, a fifth resistor R5 and a first operational amplifier U2, and the comparator includes a sixth resistor R6, a seventh resistor R7 and a second operational amplifier U3. The inductor L1 is connected to one end of the first resistor R1, one end of the fourth resistor R4, and one end of the sixth resistor R6. The other end of the first resistor R1 is connected to one end of the second resistor R2 and the positive terminal of the pump laser, and the negative terminal of the pump laser is grounded. The other end of the second resistor R2 is connected to one end of the third resistor R3 and the inverting input terminal of the first operational amplifier U2. The other end of the fourth resistor R4 is connected to one end of the fifth resistor R5 and the positive input terminal of the first operational amplifier U2, and the other end of the fifth resistor R5 is grounded. The output terminal of the first operational amplifier U2 is connected to the other end of the third resistor R3 and the positive input terminal of the second operational amplifier U3. The inverting input terminal of the second operational amplifier U3 is connected to the DA port of the microcontroller U4. One end of the seventh resistor R7 is connected to the output terminal of the second operational amplifier U3, and the other end of the seventh resistor R7 is connected to the other end of the sixth resistor R6 and the FB port of the PWM controller chip U1.

2. The constant current drive circuit for a high-current pumped laser according to claim 1, characterized in that, The TG port of the PWM controller chip U1 is connected to the gate of the first MOSFET Q1, the drain of the first MOSFET Q1 is connected to the power supply VCC, the BG port of the PWM controller chip U1 is connected to the gate of the second MOSFET Q2, the source of the second MOSFET Q2 is grounded, and the PHASE port of the PWM controller chip U1 is connected to the source of the first MOSFET Q1, the drain of the second MOSFET Q2, and one end of the inductor L1.

Images