A dual-beam laser diode driving circuit

Abstract

This invention discloses a dual-beam laser diode driving circuit based on the RN5C711, suitable for laser printers and digital copiers. The circuit uses a +5V power supply to power the AVCC, DVCC, and LDV pins of the RN5C711. The two laser diodes are connected to the LD1 and LD2 pins of the RN5C711 respectively, and independent automatic power control is achieved through adjustable resistors. It receives LVDS format data input and has overcurrent and power abnormality protection mechanisms. This circuit solves the problems of insufficient current control accuracy and lack of protection in existing technologies, achieves stable laser intensity output, extends the lifespan of the laser diodes, and is simple in design and easy to debug.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of laser diode driving, and particularly relates to a double-beam laser diode driving circuit. BACKGROUND

[0002] In the working process of laser printers and digital copying machines, the driving circuit of the laser diode is the core component determining the printing precision and service life of the equipment. The light intensity of the laser diode directly depends on the stability of the driving current. Only when the driving current is kept accurate and constant, can the clarity and consistency of the printed or copied materials be ensured. The existing laser diode driving circuit generally has the problem of insufficient current control precision. Due to the lack of a targeted double-beam independent control mechanism, the driving current is easily affected by factors such as power fluctuations and environmental temperature changes, and thus fluctuates, resulting in unstable laser intensity, and further causing problems such as blurred printing and uneven depth. The inaccuracy of current control not only affects the output quality of the equipment, but also accelerates the aging of the laser diode due to long-term work under unstable current, and reduces the overall reliability of the equipment.

[0003] Therefore, there is an urgent need for a laser diode driving circuit capable of realizing high-precision double-beam independent current control and guaranteeing stable output of laser intensity, to solve the core defects of the prior art. SUMMARY

[0004] The present invention aims to provide a dual-beam laser diode driving circuit, comprising an RN5C711 chip, a first laser diode, a second laser diode, and a monitoring photodiode. The RN5C711 chip is packaged in a QFN365X50.4 package. The circuit uses a +5V power supply, which is connected to the AVCC, DVCC, and LDV pins of the RN5C711 to power the analog, digital, and laser diode blocks. The first laser diode is connected to the LD1 pin of the RN5C711. The cathode of the first laser diode is connected to ground through a first current-limiting resistor, and the anode is connected to the LDV1 terminal through a second current-limiting resistor. The second laser diode is connected to the LD2 pin of the RN5C711. The cathodes of the two laser diodes are connected to ground via a third current-limiting resistor, and the anodes are connected to the LDV2 terminal via a fourth current-limiting resistor. The monitoring photodiode is connected to the PD pin of the RN5C711, and the cathode of the monitoring photodiode is connected to ground via a fifth current-limiting resistor. The XAPC1 pin of the RN5C711 is connected to a first adjustable resistor, and the XAPC2 pin is connected to a second adjustable resistor, used to control the automatic power control mode. The DATA1 pin of the RN5C711 is connected to the CN_DATA1_P terminal, and the DATA2 pin is connected to the CN_DATA2_P terminal to receive LVDS format data input. The XERR pin of the RN5C711 is connected to the CN_NSYNC terminal to output overcurrent and LDV power supply abnormality detection signals to trigger the protection mechanism.

[0005] Preferably, the +5V power supply is connected to multiple decoupling capacitors, which are connected in parallel between the AVCC pin and ground, the DVCC pin and ground, and the LDV pin and ground, respectively, to stabilize the power supply voltage and reduce noise and power fluctuations.

[0006] Preferably, the CSH1 pin of the RN5C711 is connected to the first phase compensation capacitor, and the CSH2 pin is connected to the second phase compensation capacitor. The first and second phase compensation capacitors are used for phase compensation of the automatic power control loop to ensure the stability of the automatic power control system.

[0007] Preferably, the VREF pin of the RN5C711 is connected to a reference voltage capacitor, and the VREF pin outputs a 1.2V reference voltage to provide a reference for other circuits.

[0008] Preferably, the circuit is provided with multiple test points, including a first test point for measuring the driving current of the first laser diode, a second test point for measuring the driving current of the second laser diode, and a third test point for measuring the power supply voltage, which facilitates circuit debugging and performance testing.

[0009] Preferably, the DATA1B pin of the RN5C711 is connected to the CN_DATA1_N end, and the DATA2B pin is connected to the CN_DATA2_N end, for receiving anti-phase signals in LVDS format, to ensure the stability of data transmission.

[0010] Preferably, the RST pin of the RN5C711 is connected to the CN_ENB end, for realizing reset control of the circuit, to ensure that the circuit is in a stable initial state when starting.

[0011] Preferably, the ILDM pin of the RN5C711 is connected to a current monitoring capacitor, for monitoring the driving current of the first and second laser diodes through the ILDM pin, to ensure that the driving current is within a safe range.

[0012] Preferably, the RPD1 pin of the RN5C711 is connected to ground through a sixth current limiting resistor, and the RPD2 pin is connected to ground through a seventh current limiting resistor, and the sixth and seventh current limiting resistors are used to set the monitoring current of the monitoring photodiode.

[0013] Preferably, the XDOFFI pin and the XDOFFO pin of the RN5C711 are left unconnected, and the circuit does not support a 4-channel laser diode array interface, but focuses on the dual-beam driving function.

[0014] Compared with the prior art, the present application has the following beneficial effects:

[0015] The core creative technical point of the present application is to use the RN5C711 chip to build a dual-beam independent control architecture, to realize precise automatic power control of the two laser diodes through independent adjustable resistors, and to solve the core problem of insufficient current control precision in the prior art by cooperating with current limiting resistors and overcurrent protection mechanisms. The two laser diodes each obtain stable driving current, and the consistency of laser intensity output is significantly improved. At the same time, overcurrent and power abnormal protection effectively avoid damage to the laser diode, prolong the service life of the equipment, and the overall design of the circuit is simple and easy to debug. BRIEF DESCRIPTION OF DRAWINGS

[0016] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or prior art description. Obviously, the drawings in the following description are only exemplary, and for those skilled in the art, other drawings can be obtained from the provided drawings without creative labor.

[0017] Figure 1 is a dual-beam laser diode driving circuit diagram of the present application;

[0018] Figure 2 is a power management module circuit diagram of the present application;

[0019] Figure 3 Laser diode connection circuit diagram of the present application;

[0020] Figure 4 Automatic power control circuit diagram of the present application. DETAILED DESCRIPTION

[0021] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative work fall within the protection scope of the present application.

[0022] The concepts involved in the present application will be described first below with reference to the drawings. It should be pointed out here that the following descriptions of the concepts are only to make the content of the present application easier to understand, and do not represent the limitation on the protection scope of the present application; meanwhile, the embodiments in the present application and the features in the embodiments can be combined with each other without conflict. The present application will be described in detail below with reference to the drawings and in combination with the embodiments.

[0023] The traditional technical solutions have the following technical problems: the existing laser diode driving circuit lacks a double-beam independent precise current control mechanism, the driving current is easy to be disturbed and fluctuate, which leads to unstable laser intensity, affects the printing and copying quality, and lacks effective protection measures.

[0024] Based on this, please refer to Figures 1-4The embodiment provides a double-beam laser diode driving circuit, which comprises an RN5C711 chip, a first laser diode, a second laser diode and a monitoring photodiode, the RN5C711 chip adopts QFN365X50.4 packaging, the circuit adopts a +5V power supply, the +5V power supply is connected with an AVCC pin, a DVCC pin and an LDV pin of the RN5C711 respectively, and supplies power for an analog part, a digital part and a laser diode block; the first laser diode is connected with an LD1 pin of the RN5C711, a cathode of the first laser diode is connected with the ground through a first current-limiting resistor, and an anode is connected with an LDV1 end through a second current-limiting resistor; the second laser diode is connected with an LD2 pin of the RN5C711, a cathode of the second laser diode is connected with the ground through a third current-limiting resistor, and an anode is connected with an LDV2 end through a fourth current-limiting resistor; the monitoring photodiode is connected with a PD pin of the RN5C711, and a cathode of the monitoring photodiode is connected with the ground through a fifth current-limiting resistor; an XAPC1 pin of the RN5C711 is connected with a first adjustable resistor, and an XAPC2 pin is connected with a second adjustable resistor, and is used for controlling an automatic power control mode; a DATA1 pin of the RN5C711 is connected with a CN_DATA1_P end, a DATA2 pin is connected with a CN_DATA2_P end, and LVDS format data input is received; and an XERR pin of the RN5C711 is connected with a CN_NSYNC end, and is used for outputting an overcurrent and LDV power supply abnormality detection signal and triggering a protection mechanism.

[0025] In the technical scheme, the RN5C711 chip is used as a core control unit, AVCC, DVCC and LDV pins of the chip are supplied with +5V power supply respectively, independent power supply of the analog part, the digital part and the laser diode block is realized, and interference between different parts is avoided. The first laser diode and the second laser diode are connected to the corresponding pins and the power supply end of the chip through independent current-limiting resistors respectively, the current-limiting resistors can limit the working current of the laser diode, and prevent the current from being too large. The monitoring photodiode collects the laser output intensity signal in real time and feeds back to the PD pin, and the adjustable resistors of the XAPC1 and XAPC2 pins form two independent automatic power control loops, the target intensity of the two laser diodes can be adjusted respectively, and the stability of the laser output is ensured. The LVDS format data input received by the DATA1 and DATA2 pins has the characteristics of strong anti-interference ability, and the data transmission is accurate. The connection of the XERR pin and the CN_NSYNC end enables the circuit to output signals in time when overcurrent or LDV power supply abnormality is detected, and triggers the protection mechanism.

[0026] The scheme realizes precise adjustment of the driving current through the double-beam independent control architecture and the automatic power control loop, solves the problem of unstable laser intensity, the overcurrent protection mechanism effectively protects the laser diode, and improves the reliability of the circuit.

[0027] The prior art has the following technical problems: the power supply voltage of the existing drive circuit is easily affected by noise and fluctuation, which in turn causes the drive current to be unstable, affecting the working performance of the laser diode.

[0028] Therefore, the +5V power supply is connected with multiple decoupling capacitors, which are respectively connected in parallel between the AVCC pin and the ground, between the DVCC pin and the ground, and between the LDV pin and the ground, for stabilizing the power supply voltage and reducing noise and power supply fluctuation.

[0029] In the technical solution, the decoupling capacitors are made of X7R or NPO materials, which have good temperature stability and frequency characteristics. The decoupling capacitor connected in parallel between the AVCC pin and the ground can filter high-frequency noise in the analog power supply circuit, ensuring the stability of analog signal processing; the decoupling capacitor connected between the DVCC pin and the ground filters the noise interference generated by the switching action of the digital circuit; and the decoupling capacitor connected between the LDV pin and the ground stabilizes the power supply voltage of the laser diode block, avoiding voltage fluctuation that causes changes in the laser drive current. The multiple decoupling capacitors work together to suppress noise and fluctuation from the power source, providing a stable and reliable power supply environment for the entire circuit.

[0030] The technical solution effectively stabilizes the power supply voltage of each part by targeted decoupling capacitor layout, reduces noise interference, provides a basis for precise current control, and further improves the stability of laser output.

[0031] The prior art has the following technical problems: the automatic power control loop is prone to phase shift, causing the control system to be unstable and unable to achieve precise and stable control of the laser intensity.

[0032] Therefore, the CSH1 pin of the RN5C711 is connected with a first phase compensation capacitor, and the CSH2 pin is connected with a second phase compensation capacitor, which are used for phase compensation of the automatic power control loop, ensuring the stability of the automatic power control system.

[0033] In the technical solution, the first phase compensation capacitor corresponds to the automatic power control loop of the first laser diode, and the second phase compensation capacitor corresponds to the automatic power control loop of the second laser diode. The phase compensation capacitor adjusts the phase characteristics of the loop to compensate for the phase lag in the loop, avoiding the situation where the phase shift exceeds 180 degrees when the loop gain is positive, thereby preventing system oscillation. The capacitance value of the capacitor is precisely matched to ensure that the loop stability margin is maintained under different working conditions, enabling the automatic power control to quickly respond to changes in laser intensity and adjust the drive current in a timely manner, ensuring the constancy of the laser output intensity.

[0034] The scheme solves the stability problem of the automatic power control loop, improves the response speed and accuracy of the current regulation, and ensures the stability and consistency of the dual-beam laser intensity through the design of independent phase compensation capacitors.

[0035] The traditional technical solution has the following technical problems: the circuit lacks a stable reference voltage reference, resulting in insufficient working accuracy of the related control circuit, affecting the accuracy of current control.

[0036] Based on this, the VREF pin of the RN5C711 is connected to the reference voltage capacitor, which outputs a 1.2V reference voltage to provide a reference for other circuits.

[0037] In this technical solution, the reference voltage capacitor is made of X7R material and is connected in parallel between the VREF pin and the ground to filter out ripple noise in the reference voltage and ensure the stability of the 1.2V reference voltage. The stable reference voltage output by the VREF pin provides an accurate voltage reference for the automatic power control loop, current monitoring circuit, etc., so that the threshold judgment, signal comparison, etc. of the related circuit have a unified reference standard. For example, during the automatic power control process, the control circuit compares the 1.2V reference voltage with the signal feedback by the monitoring photodiode, and then adjusts the driving current accurately to ensure that the laser intensity reaches the target value.

[0038] This scheme provides an accurate reference through a stable reference voltage, improves the working accuracy of the related control circuit, and provides protection for accurate current control, further optimizing the laser output effect.

[0039] The traditional technical solution has the following technical problems: circuit debugging and performance testing are not convenient, it is difficult to quickly locate faults and optimize parameters, affecting product development efficiency and post-maintenance convenience.

[0040] Based on this, the circuit is provided with multiple test points, including a first test point for measuring the driving current of the first laser diode, a second test point for measuring the driving current of the second laser diode, and a third test point for measuring the power supply voltage, facilitating circuit debugging and performance testing.

[0041] In this technical solution, the first test point is arranged on the connection line between the first laser diode and the LD1 pin, and the driving current of the first laser diode can be directly measured by a multimeter or other test equipment; the second test point is arranged on the connection line between the second laser diode and the LD2 pin, for measuring the driving current of the second laser diode; and the third test point is arranged on the connection line between the +5V power supply and the chip pin, for monitoring the stability of the power supply voltage. In addition, the circuit can also set test points for measuring parameters such as reference voltage and automatic power control signal according to demand, and the layout of the test points is reasonable, facilitating the contact of the test probe and not affecting the normal operation of the circuit.

[0042] The scheme sets specific test points, facilitates parameter debugging and fault troubleshooting in the research and development stage, and is convenient for maintenance and detection of the product in the later stage, thereby improving the practicability and maintainability of the circuit.

[0043] The traditional technical scheme has the following technical problems: the data transmission process is prone to interference, resulting in signal distortion, affecting the driving control accuracy of the laser diode.

[0044] Based on this, the DATA1B pin of the RN5C711 is connected to the CN_DATA1_N end, and the DATA2B pin is connected to the CN_DATA2_N end, for receiving the anti-phase signal in the LVDS format, to ensure the stability of data transmission.

[0045] In the technical scheme, the DATA1 pin and the DATA1B pin, and the DATA2 pin and the DATA2B pin respectively form a differential signal pair, for receiving the positive-phase signal and the anti-phase signal in the LVDS format. The LVDS format adopts a differential transmission mode, has the characteristics of strong anti-interference ability and high transmission rate, and can effectively suppress the influence of common-mode noise. In the complex electromagnetic environment of the laser printer and the digital copier, differential signal transmission can reduce the influence of external interference on the data signal, ensure that the control data is accurately transmitted to the RN5C711 chip, and the chip adjusts the driving state of the laser diode according to the received accurate data, to ensure the consistency of the laser output and the control instruction.

[0046] The scheme adopts LVDS differential signal transmission to improve the anti-interference ability and stability of data transmission, and provides a reliable data basis for accurate driving control.

[0047] The traditional technical scheme has the following technical problems: the circuit is prone to be in an unstable state when starting, which may cause the laser diode to malfunction or the driving current to be abnormal, affecting the starting reliability of the equipment.

[0048] Based on this, the RST pin of the RN5C711 is connected to the CN_ENB end, for realizing reset control of the circuit, to ensure that the circuit is in a stable initial state when starting.

[0049] In the technical scheme, the CN_ENB end outputs a reset control signal to the RST pin. When the circuit is powered on, the reset control signal triggers the RN5C711 chip to perform a reset operation, the control logic, registers and the like in the chip are restored to the initial state, all output signals are in a preset stable state, and the driving current of the laser diode is initialized to a safe value. After the reset is completed, the circuit starts to work normally, avoiding problems such as abnormal driving current or laser diode mislighting caused by uncertain chip state during the power-on process, and ensuring the smooth and reliable starting process of the equipment.

[0050] The scheme guarantees the stable initial state of the circuit during startup through the reset control function, avoids abnormal conditions during the startup stage, and improves the overall reliability of the device.

[0051] The traditional technical solution has the following technical problems: lack of real-time monitoring means for the driving current of the laser diode, unable to timely detect current abnormalities, which may cause the laser diode to be damaged due to overcurrent.

[0052] Therefore, the ILDM pin of the RN5C711 is connected to a current monitoring capacitor, the driving current of the first and second laser diodes is monitored through the ILDM pin, and it is ensured that the driving current is within a safe range.

[0053] In the technical solution, the current monitoring capacitor is connected in parallel between the ILDM pin and the ground, and is used to filter noise in the monitoring signal and improve monitoring accuracy. The ILDM pin outputs a monitoring signal related to the driving current of the first and second laser diodes in real time, and the amplitude of the monitoring signal is proportional to the driving current. The external circuit can obtain the driving current information through the pin and judge in real time whether the current is within the preset safe range. If an abnormal current is detected, other protection mechanisms can be used to take timely measures to avoid damage to the laser diode due to long-term overcurrent operation.

[0054] The scheme provides accurate signal basis for overcurrent protection by means of real-time current monitoring function, and further guarantees the safe operation of the laser diode.

[0055] The traditional technical solution has the following technical problems: the monitoring current of the monitoring photodiode is not set reasonably, resulting in insufficient feedback signal accuracy and affecting the effect of automatic power control.

[0056] Therefore, the RPD1 pin of the RN5C711 is connected to the ground through the sixth current limiting resistor, and the RPD2 pin is connected to the ground through the seventh current limiting resistor, and the sixth and seventh current limiting resistors are used to set the monitoring current of the monitoring photodiode.

[0057] In the technical solution, the resistance values of the sixth and seventh current limiting resistors are accurately calculated, and appropriate monitoring currents are set according to the working characteristics of the monitoring photodiode and the requirements of the automatic power control loop. A monitoring current that is too large may cause the photodiode to saturate and fail to accurately reflect changes in laser intensity; a current that is too small may result in a feedback signal with a low amplitude that is easily disturbed by noise. By accurately setting the monitoring current through the current limiting resistor, the monitoring photodiode is ensured to work in the best linear region, and can accurately capture subtle changes in laser intensity and output stable and reliable feedback signals to provide accurate input signals for the automatic power control loop.

[0058] The scheme improves the accuracy and reliability of the feedback signal by accurately setting the monitoring current, guarantees the effect of automatic power control, and further optimizes the stability of the laser intensity.

[0059] The traditional technical scheme has the following technical problems: some drive circuits blindly support multi-channel functions, resulting in complex circuit design, increased cost, and affecting the stability of the core dual-beam driving function.

[0060] Therefore, the XDOFFI pin and the XDOFFO pin of the RN5C711 are left hanging, the circuit does not support a 4-channel laser diode array interface, and focuses on the dual-beam driving function.

[0061] In the technical scheme, the XDOFFI pin and the XDOFFO pin are 4-channel laser diode array interface pins of the RN5C711 chip, and according to the dual-beam application requirements of the laser printer and the digital copier, the two pins are left hanging, and the 4-channel function is not enabled. This simplifies the circuit design, reduces unnecessary device connections and circuit losses, reduces the cost, simultaneously concentrates the resources of the chip to serve the dual-beam driving control, avoids the interference of the multi-channel function on the core control logic, and improves the stability and reliability of the dual-beam driving function.

[0062] The scheme simplifies unnecessary functions, focuses on the core dual-beam driving requirements, realizes simple circuit design, reduces cost, and improves the stability of the core function.

[0063] The above-described embodiments and / or implementations are merely used to illustrate the preferred embodiments and / or implementations of the present application, and do not limit the implementation of the present application in any form. Any person skilled in the art can make some changes or modifications to other equivalent embodiments without departing from the scope of the technical means disclosed in the present application, and the changes or modifications should be considered as the same technology or embodiment as the present application.

[0064] The principles and implementations of the present application are described by using specific examples in this paper, and the above embodiment description is only used to help understand the method and core idea of the present application. The above-mentioned is only the preferred embodiment of the present application. It should be pointed out that due to the limitation of language expression, there are infinite specific structures, and for ordinary skilled persons in the technical field, some improvements, refinements or changes can be made without departing from the principle of the present application, and the above technical features can be combined in a proper way. These improvements, refinements, changes or combinations, or the direct application of the inventive concept and technical scheme to other occasions without improvement, should be considered as the protection scope of the present application.

Claims

1. A dual-beam laser diode driving circuit comprising an RN5C711 chip, a first laser diode, a second laser diode and a monitoring photodiode, the RN5C711 chip adopts a QFN365X50.4 package, characterized in that: the circuit adopts a +5V power supply, the +5V power supply is connected to the AVCC pin, the DVCC pin and the LDV pin of the RN5C711 respectively to supply power to the analog part, the digital part and the laser diode block; the first laser diode is connected to the LD1 pin of the RN5C711, the cathode of the first laser diode is connected to ground through a first current-limiting resistor, and the anode is connected to LDV1 through a second current-limiting resistor; the second laser diode is connected to the LD2 pin of the RN5C711, the cathode of the second laser diode is connected to ground through a third current-limiting resistor, and the anode is connected to LDV2 through a fourth current-limiting resistor; the monitoring photodiode is connected to the PD pin of the RN5C711, and the cathode of the monitoring photodiode is connected to ground through a fifth current-limiting resistor; the XAPC1 pin of the RN5C711 is connected to a first adjustable resistor, and the XAPC2 pin is connected to a second adjustable resistor for controlling the automatic power control mode; the DATA1 pin of the RN5C711 is connected to the CN_DATA1_P terminal, and the DATA2 pin is connected to the CN_DATA2_P terminal to receive LVDS format data input; the XERR pin of the RN5C711 is connected to the CN_NSYNC terminal for outputting overcurrent and LDV power supply abnormal detection signals to trigger a protection mechanism; the +5V power supply is connected to a plurality of decoupling capacitors which are connected in parallel between the AVCC pin and ground, between the DVCC pin and ground, and between the LDV pin and ground; the CSH1 pin of the RN5C711 is connected to a first phase compensation capacitor, and the CSH2 pin is connected to a second phase compensation capacitor; the VREF pin of the RN5C711 is connected to a reference voltage capacitor; the DATA1B pin of the RN5C711 is connected to the CN_DATA1_N terminal, and the DATA2B pin is connected to the CN_DATA2_N terminal; the RST pin of the RN5C711 is connected to the CN_ENB terminal; the ILDM pin of the RN5C711 is connected to a current monitoring capacitor; the RPD1 pin of the RN5C711 is connected to ground through a sixth current-limiting resistor, and the RPD2 pin is connected to ground through a seventh current-limiting resistor; the XDOFFI pin and the XDOFFO pin of the RN5C711 are left empty. The +5V power supply is connected to a plurality of decoupling capacitors which are connected in parallel between the AVCC pin and ground, between the DVCC pin and ground, and between the LDV pin and ground to stabilize the power supply voltage, reduce noise and power supply fluctuations. The CSH1 pin of the RN5C711 is connected to a first phase compensation capacitor, and the CSH2 pin is connected to a second phase compensation capacitor, which are used for phase compensation of the automatic power control loop to ensure the stability of the automatic power control system. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 2. The dual-beam laser diode drive circuit of claim 1, wherein, ​ 3. The dual-beam laser diode drive circuit of claim 1, wherein, ​ 4. The dual-beam laser diode drive circuit of claim 1, wherein, The VREF pin of the RN5C711 is connected with a reference voltage capacitor, which outputs a 1.2V reference voltage to provide a reference for other circuits.

5. The dual-beam laser diode drive circuit of claim 1, wherein, The circuit is provided with multiple test points, including a first test point for measuring the first laser diode driving current, a second test point for measuring the second laser diode driving current, and a third test point for measuring the power supply voltage, facilitating circuit debugging and performance detection.

6. The dual-beam laser diode drive circuit of claim 1, wherein, The DATA1B pin of the RN5C711 is connected with the CN_DATA1_N terminal, and the DATA2B pin is connected with the CN_DATA2_N terminal, for receiving inverted signals in LVDS format to ensure the stability of data transmission.

7. The dual-beam laser diode drive circuit of claim 1, wherein, The RST pin of the RN5C711 is connected with the CN_ENB terminal, for realizing reset control of the circuit to ensure that the circuit is in a stable initial state when starting.

8. The dual-beam laser diode drive circuit of claim 1, wherein, The ILDM pin of the RN5C711 is connected with a current monitoring capacitor, through which the driving currents of the first and second laser diodes are monitored to ensure that the driving currents are within a safe range.

9. The dual-beam laser diode drive circuit of claim 1, wherein, The RPD1 pin of the RN5C711 is connected with the ground through a sixth current limiting resistor, and the RPD2 pin is connected with the ground through a seventh current limiting resistor, which are used to set the monitoring current of the monitoring photodiode.

10. The dual-beam laser diode drive circuit of claim 1, wherein, The XDOFFI pin and the XDOFFO pin of the RN5C711 are left empty, and the circuit does not support a 4-channel laser diode array interface, focusing on the dual-beam driving function.

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