A high-frequency controlled constant current source control circuit and a laser drive circuit

Abstract

The present invention discloses a high-frequency controlled constant current source control circuit and a laser driving circuit, belonging to the technical field of control and modulation of constant current source control circuits and lasers. A high-frequency controlled constant current source control circuit of the present invention is provided with a voltage input unit, a voltage negative feedback control unit, an analog load unit, and a high-frequency signal modulation unit. During operation, the analog load unit is connected in parallel with the actually operating load, and their working states are mutually exclusive. The working state of the load is modulated through the high-frequency signal modulation unit, which can make the working current stable, the voltage drop generated by the wire stable, and the current output by the power supply stable. As a result, the influence on the load during high-frequency switching is extremely small, ensuring the working effect of the circuit. Further, the present invention can be applied to many fields, especially in the occasions where multiple lasers need to be used simultaneously and the working current is relatively large. Moreover, the present invention can effectively avoid the impact of large power supplies, make the voltage drop on the wire stable, and ensure the stable and reliable power output of the laser.

Description

Technical Field

[0001] The present invention relates to a high-frequency controlled constant current source control circuit and a laser driving circuit, belonging to the technical field of control and modulation of constant current source control circuits and lasers. Background Art

[0002] Currently, most high-precision constant current sources use integrated operational amplifiers. Its basic principle is to make the voltages applied to the two input terminals of the comparison amplifier equal through negative feedback, so as to keep the output current constant. The control circuit of the constant current source basically provides a stable current output to the load and cannot achieve high-frequency switching control. Some integrated chips of mirror power supplies can indeed achieve high-frequency modulation, but the current is generally relatively small, basically not exceeding 500 mA.

[0003] Especially in the field of high-power semiconductor laser control, since semiconductor lasers are current elements, it is necessary to control the current of the laser, and generally the current is relatively large.

[0004] Moreover, in many application fields, multiple lasers need to be used simultaneously, and the working current may be even larger, reaching 100 A, which will cause a large voltage drop in the wire; on the other hand, semiconductor lasers require high-frequency switching control, and the frequency needs to reach several megahertz or even more than a dozen megahertz, which has a huge impact on the power supply. The high-frequency change of the voltage drop on the wire will also affect the sampling of the current source negative feedback, resulting in unstable power output of the laser.

[0005] Furthermore, with the changes in the international market, high-speed operational amplifiers and high-power high-frequency MOS transistors are expensive and not easy to purchase. Therefore, directly implementing high-frequency modulation of the constant current source through high-speed operational amplifiers and high-frequency MOS transistors is expensive and the device selection range is very narrow. Currently, high-frequency switching control of semiconductor lasers mainly uses integrated chips of mirror current sources, and the controlled current is generally about several hundred milliamperes, which cannot meet the requirements of application fields such as high-power semiconductor laser control. Summary of the Invention

[0006] Aiming at the defects of the prior art, the first object of the present invention is to provide a high-frequency controlled constant current source control circuit provided with a voltage input unit, a voltage negative feedback control unit, an analog load unit, and a high-frequency signal modulation unit. When working, the analog load unit is connected in parallel with the actual working load, and the working states are mutually exclusive, and the working state of the load is modulated through the high-frequency signal modulation unit, so that the working current is stable, the voltage drop generated by the wire is stable, and the current output by the power supply is stable, thereby minimizing the influence on the load during high-frequency switching and ensuring the working effect of the circuit.

[0007] The second object of the present invention is to provide a control circuit for a high-frequency controlled constant current source that can be applied to many fields, especially in occasions where multiple lasers need to be used simultaneously and the working current is relatively large; it can perform high-frequency switching control on semiconductor lasers, with a control frequency that can reach several megahertz or even more than a dozen megahertz, and the present invention can effectively avoid the impact of large power supplies, thereby effectively improving the sampling accuracy of the current source negative feedback, making the laser power output stable and reliable.

[0008] The third object of the present invention is to provide a control circuit for a high-frequency controlled constant current source that uses ordinary components such as operational amplifiers, MOS transistors, drivers, and inverters, is easy to produce, has a very low manufacturing cost, a wide selection range, is not easily subject to foreign blockades, and can meet the requirements of application fields such as high-power semiconductor laser control at the same time.

[0009] The fourth object of the present invention is to provide a laser drive circuit that applies a high-frequency controlled constant current source control circuit, can make the voltage drop generated by the wire stable, and thus the current output by the power supply is stable, ensuring the working effect of the circuit and ensuring stable power output.

[0010] To achieve one of the above objects, the first technical solution of the present invention is as follows:

[0011] A control circuit for a high-frequency controlled constant current source,

[0012] including a voltage input unit, a voltage negative feedback control unit, an analog load unit, and a high-frequency signal modulation unit;

[0013] The voltage input unit is provided with operational amplifier U1A and operational amplifier U1B;

[0014] The operational amplifier U1A and the operational amplifier U1B are connected in parallel to control the working current of the constant current source;

[0015] The voltage negative feedback control unit is provided with operational amplifier U2B and triode Q1;

[0016] The operational amplifier U2B and the triode Q1 are connected in series for voltage feedback control;

[0017] The analog load unit is provided with an analog load for load simulation;

[0018] The high-frequency signal modulation unit is provided with inverter U2, MOS transistor driver U3, MOS transistor driver U4, MOS transistor M1, and MOS transistor M2 for high-frequency signal modulation;

[0019] The inverter U2, the MOS transistor driver U3, and the MOS transistor M1 are connected in series;

[0020] The MOS transistor driver U4 and the MOS transistor M2 are connected in series.

[0021] Through continuous exploration and experimentation, the present invention is provided with a voltage input unit, a voltage negative feedback control unit, an analog load unit, and a high-frequency signal modulation unit. During operation, the analog load unit is connected in parallel with the actual working load, and their working states are mutually exclusive. The working state of the load is modulated by the high-frequency signal modulation unit, which can stabilize the working current, the voltage drop generated by the wire, and the current output by the power supply, thereby minimizing the impact on the load during high-frequency switching and ensuring the working effect of the circuit.

[0022] Furthermore, the present invention is applicable to many fields, especially in the occasions where multiple lasers need to be used simultaneously and the working current is relatively large. The present invention can perform high-frequency switching control on semiconductor lasers, with a control frequency that can reach several megahertz or even more than a dozen megahertz. Moreover, the present invention can effectively avoid the impact of large currents, stabilize the voltage drop on the wire, and then effectively improve the sampling accuracy of the current source negative feedback, making the laser power output stable and reliable.

[0023] Even further, the circuit units of the present invention adopt ordinary components such as operational amplifiers, MOS transistors, drivers, and inverters, which are easy to manufacture, have a very low manufacturing cost, a wide selection range, and are not easily restricted by foreign blockades. At the same time, the control current of the present invention can meet the requirements of application fields such as high-power semiconductor laser control.

[0024] As a preferred technical measure:

[0025] A capacitor C1 and a resistor R2 are connected in parallel with the operational amplifier U1A, and a resistor R7 is connected in series.

[0026] The positive input terminal of the operational amplifier U1A is electrically connected to a resistor R6 and a capacitor C5 in sequence, and its negative input terminal is electrically connected to a resistor R5.

[0027] A capacitor C9 and a resistor R10 are connected in parallel with the operational amplifier U1B, and a resistor R13 is connected in series.

[0028] The positive input terminal of the operational amplifier U1B is electrically connected to a resistor R14, and its negative input terminal is electrically connected to a resistor R18.

[0029] As a preferred technical measure:

[0030] The positive input terminal of the operational amplifier U2B is electrically connected to R7 of the voltage input unit, its negative input terminal is electrically connected to the analog load, and its output terminal is connected in series with a resistor R1.

[0031] One branch of the resistor R1 is electrically connected to the capacitor C2, and the other branch is connected to the base of the triode Q1.

[0032] One branch of the emitter of the triode Q1 is connected to the load, and the other branch is connected to the first group of polarized capacitors;

[0033] One branch of the collector of the triode Q1 is connected to the load voltage, and the other branch is connected to the second group of polarized capacitors.

[0034] As a preferred technical measure:

[0035] The first group of polarized capacitors includes the polarized capacitor C6 and the capacitor C7;

[0036] The polarized capacitor C6 and the capacitor C7 are connected in parallel and grounded;

[0037] The second group of polarized capacitors includes the polarized capacitor C4 and the capacitor C3;

[0038] The polarized capacitor C4 and the capacitor C3 are connected in parallel and grounded.

[0039] As a preferred technical measure:

[0040] The analog load is a resistor or / and a diode group;

[0041] The diode group includes the diode D2 or / and the diode D3 or / and the diode D4.

[0042] As a preferred technical measure:

[0043] A first filtering unit is connected in parallel to the MOS transistor M1;

[0044] The first filtering unit includes the capacitor C13 and the resistor R26;

[0045] The capacitor C13 and the resistor R26 are connected in parallel;

[0046] A second filtering unit is connected in parallel to the MOS transistor M2;

[0047] The second filtering unit includes the capacitor C14 and the resistor R27;

[0048] The capacitor C14 and the resistor R27 are connected in parallel.

[0049] As a preferred technical measure:

[0050] A current sampling and detection unit is provided between the voltage negative feedback control unit and the high-frequency signal modulation unit;

[0051] The current sampling and detection unit is provided with the operational amplifier U3A, the operational amplifier U3B, and the resistor R16;

[0052] The operational amplifier U3A, the operational amplifier U3B, and the resistor R16 are connected in series for current sampling and detection;

[0053] A threshold current setting unit is provided between the current sampling and detection unit and the high-frequency signal modulation unit;

[0054] The threshold current setting unit is provided with a zener diode D5, a triode Q2, an inverter U2A, and a constant current source BVIN;

[0055] One end of the zener diode D5 is connected to the positive input terminal of the inverter U2A, and the other end is grounded;

[0056] The triode Q2, the inverter U2A, and the constant current source BVIN are connected in series in sequence for threshold current control.

[0057] As a preferred technical measure:

[0058] The operational amplifier U3A is connected in parallel with a capacitor C8 and a resistor R8, and is connected in series with a resistor R12;

[0059] The positive input terminal of the operational amplifier U3A is electrically connected to a resistor R17, and its negative input terminal is electrically connected to a resistor R11;

[0060] The operational amplifier U3B is connected in parallel with a capacitor C11 and a resistor R19;

[0061] One branch of the positive input terminal of the operational amplifier U3B is electrically connected to a resistor R9 and a capacitor C10, and the other branch is connected to a resistor R15;

[0062] The negative input terminal of the operational amplifier U3B is electrically connected to a resistor R20.

[0063] As a preferred technical measure:

[0064] The emitter of the triode Q2 is connected to the resistor R29, its collector is connected in series with a resistor R21 and an inductor L1, and its base is electrically connected to the resistor R24;

[0065] A resistor R22, a resistor R23, a resistor R25, and a capacitor C12 are provided between the inverter U2A and the constant current source BVIN.

[0066] To achieve one of the above purposes, the second technical solution of the present invention is:

[0067] A high-frequency controlled constant current source control circuit,

[0068] including a voltage input unit, a voltage negative feedback control unit, an analog load unit, a current sampling and detection unit, a threshold current setting unit, and a high-frequency signal modulation unit;

[0069] The voltage input unit is provided with an operational amplifier U1B and an operational amplifier U1A;

[0070] The operational amplifier U1B and the operational amplifier U1A are connected in parallel to control the working current of the constant current source;

[0071] The voltage negative feedback control unit is provided with an operational amplifier U1 and a triode Q1;

[0072] The operational amplifier U1 and the triode Q1 are connected in series;

[0073] The analog load unit is provided with an analog load;

[0074] The current sampling and detection unit is provided with an operational amplifier U3A, an operational amplifier U3B, and a resistor R16;

[0075] The operational amplifier U3A, the operational amplifier U3B, and the resistor R16 are connected in series for current sampling and detection;

[0076] The threshold current setting unit is provided with a zener diode D5, a triode Q2, an inverter U2A, and a constant current source BVIN;

[0077] One end of the zener diode D5 is connected to the positive input terminal of the inverter U2A, and the other end is grounded;

[0078] The triode Q2, the inverter U2A, and the constant current source BVIN are connected in series in sequence for threshold current control;

[0079] The high-frequency signal modulation unit is provided with an inverter U2, a MOS transistor driver U3, a MOS transistor driver U4, a MOS transistor M1, and a MOS transistor M2 for high-frequency signal modulation;

[0080] The inverter U2, the MOS transistor driver U3, and the MOS transistor M1 are connected in series;

[0081] The MOS transistor driver U4 and the MOS transistor M2 are connected in series.

[0082] To achieve one of the above purposes, the third technical solution of the present invention is:

[0083] A laser driving circuit applies the above-mentioned high-frequency controlled constant current source control circuit.

[0084] By applying the above-mentioned high-frequency controlled constant current source control circuit, the present invention can make the voltage drop generated by the wire stable, and then the current output by the power supply stable, ensuring the working effect of the circuit and the stable output of the laser power.

[0085] Compared with the prior art, the present invention has the following beneficial effects:

[0086] Through continuous exploration and experimentation, the present invention is provided with a voltage input unit, a voltage negative feedback control unit, an analog load unit, and a high-frequency signal modulation unit. During operation, the analog load unit is connected in parallel with the actually operating load, and their operating states are mutually exclusive. The high-frequency signal modulation unit modulates the operating state of the load, enabling the working current to be stable, the voltage drop generated by the wire to be stable, and the current output by the power supply to be stable. As a result, the impact on the load during high-frequency switching is extremely small, ensuring the working effect of the circuit.

[0087] Furthermore, the present invention can be applied to many fields, especially in situations where multiple lasers need to be used simultaneously and the working current is relatively large. The present invention can perform high-frequency switching control on semiconductor lasers, with a control frequency that can reach several megahertz or even more than ten megahertz. Moreover, the present invention can effectively avoid the impact of large power supplies, making the voltage drop on the wire stable. Furthermore, it can effectively improve the sampling accuracy of the current source negative feedback, ensuring stable and reliable power output of the laser.

[0088] Even further, the circuit units of the present invention adopt ordinary components such as operational amplifiers, MOS transistors, drivers, and inverters, which are easy to produce, have very low manufacturing costs, a wide selection range, and are not easily subject to foreign blockades. At the same time, the control current of the present invention can meet the requirements of application fields such as high-power semiconductor laser control. BRIEF DESCRIPTION OF THE DRAWINGS

[0089] Figure 1 is the first structural diagram of the control circuit of the present invention;

[0090] Figure 2 is the second structural diagram of the control circuit of the present invention.

[0091] DESCRIPTION OF THE REFERENCE NUMERALS:

[0092] Vin is the working current of the current source, which is set by the voltage input unit;

[0093] PULSE is the pulse modulation signal;

[0094] U2B is an operational amplifier, which is an important part of the voltage negative feedback;

[0095] Q1 is a high-power triode, which can control the output of the current source;

[0096] DR2 is the analog load;

[0097] LD is the load, and its typical load is a semiconductor laser;

[0098] U2 is an inverter, which reverses the pulse modulation signal;

[0099] U3 and U4 are MOS transistor drivers;

[0100] M1 and M2 are MOS transistors;

[0101] VLD is the voltage across the load LD. Specific embodiments

[0102] In order to make the objectives, technical solutions and advantages of the present invention more clear and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0103] On the contrary, the present invention covers any alternatives, modifications, equivalent methods and solutions made within the spirit and scope of the present invention defined by the claims. Further, in order to enable the public to have a better understanding of the present invention, some specific details are described in detail in the following detailed description of the present invention. Those skilled in the art can fully understand the present invention without the description of these details.

[0104] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the technical field to which the present invention belongs. The terms used herein are only for the purpose of describing specific embodiments and are not intended to limit the present invention. The term "or / and" used herein includes any and all combinations of one or more of the related listed items.

[0105] Figure 1 As shown, the first specific embodiment of the high-frequency controlled constant current source control circuit of the present invention:

[0106] A high-frequency controlled constant current source control circuit includes a voltage input unit, a voltage negative feedback control unit, an analog load unit, and a high-frequency signal modulation unit.

[0107] The voltage input unit is provided with an operational amplifier U1A and an operational amplifier U1B;

[0108] The operational amplifier U1A and the operational amplifier U1B are connected in parallel to control the working current of the constant current source;

[0109] The voltage negative feedback control unit is provided with an operational amplifier U2B and a triode Q1;

[0110] The operational amplifier U2B and the triode Q1 are connected in series for voltage feedback control;

[0111] The analog load unit is provided with an analog load for load simulation;

[0112] The high-frequency signal modulation unit is provided with an inverter U2, MOS transistor drivers U3, U4, MOS transistors M1, and M2 for high-frequency signal modulation;

[0113] The inverter U2, the MOS transistor driver U3, and the MOS transistor M1 are connected in series.

[0114] The MOS transistor driver U4 and the MOS transistor M2 are connected in series.

[0115] The second specific embodiment of the high-frequency controlled constant current source control circuit of the present invention:

[0116] A high-frequency controlled constant current source control circuit includes a voltage input unit, a voltage negative feedback control unit, an analog load unit, and a high-frequency signal modulation unit.

[0117] The voltage generated by the voltage input unit is input to the 5th pin of the operational amplifier, and then through the voltage feedback circuit, the voltages applied to the two input terminals of the operational amplifier are made equal, that is, the voltage at the 3rd pin of Q3 is equal to Vin. The current IR2 flowing through the analog load DR2 = (Vin - VMOSM1) / analog load DR2. Since the on-voltage of the MOS transistor M1 is very small, it can be ignored. Then IDR2 = Vin / analog load DR2. By the same token, ILD = Vin / RLD. When the load is determined, the current flowing through the load is also correspondingly determined. Therefore, the working current of the load of this circuit is completely controlled by Vin. Then, the high-frequency modulation unit composed of the MOS transistor M1, the MOS transistor M2, and the pulse modulation signal controls the high-frequency switching of the current of the load. Because an inverter is added in front of the MOS transistor M1, the working states of the MOS transistor M1 and the MOS transistor M2 are opposite. When the MOS transistor M1 is on, the MOS transistor M2 is off; when the MOS transistor M1 is off, the MOS transistor M2 is on. Therefore, the purpose of controlling the switching of the load LD through the PULSE pulse modulation signal is achieved.

[0118] Since the output current of the triode Q1 is stable and does not require high-frequency switching, the operational amplifier U1 does not need a high-speed operational amplifier, and the triode Q1 does not need a high-frequency transistor. The MOS transistor M1 and the MOS transistor M1 work in a saturated switching state, and the voltage drop is very small, so the power is also very small. It is easy to select components and the price is cheap. During high-frequency modulation, the current switches back and forth between the load and the analog load, the working current of the current source is stable, and the voltage drop of the wire is also stable. No matter how many semiconductor lasers work simultaneously and randomly switch at high frequency, it cannot affect the change of the output current of the current source, which is very stable.

[0119] Of course, in actual applications, this circuit also needs to be refined to make the designed product easier to produce and debug.

[0120] The present invention provides a control method for a high-frequency controlled current source that does not require expensive high-frequency operational amplifiers and high-frequency MOS transistors. Instead, ordinary devices can be used to achieve the control of a high-frequency controlled current source. Moreover, it can stably output current, and this current can be switched at high frequency, improving the output current adjustment range of the current source. At the same time, it is also very convenient to be applied to various actual situations. Especially in the case where multiple current devices are used in parallel and random high-frequency switching is required, it avoids the interference of wire voltage drop caused by large currents. The present invention is particularly suitable for the control and modulation of high-power semiconductor lasers.

[0121] As Figure 2 shown, the third specific embodiment of the high-frequency controlled constant current source control circuit of the present invention:

[0122] A high-frequency controlled constant current source control circuit includes a voltage input unit, a voltage negative feedback control unit, a load, an analog load, a current sampling and detection unit, a threshold current setting unit, and a high-frequency signal modulation unit.

[0123] First, in the voltage input unit, VREF is the reference set voltage, which is set to 2.5V in this embodiment. Because the basic principle of an operational amplifier is to make the voltages applied to the two input terminals of the comparison amplifier equal through negative feedback, so VREF / R14 = (VIN1 - VREF) / R10, that is, VIN1 / VREF = (R14 + R10) / R14.

[0124] Since R14 = R10, it is known that the amplification factor of operational amplifier U1B is 2. Therefore, VREF is amplified by 2 times by operational amplifier U1B, and VIN1 = 5V. VSET is the working voltage set by the MCU. In this embodiment, the set voltage range is 0V < VSET < 2.5V. Similarly, since the resistance of the analog load DR2 = R5 * 2.2, it is known that the amplification factor of operational amplifier U1A is 3.2. Therefore, VSET is amplified by 3.2 times by operational amplifier U1A, and the voltage range of VIN2 is 0V < VIN2 < 8V. Since R7 = R13, according to the principle of voltage division, the voltage range of VIN is 2.5V < VIN < 6.5V. D1 plays a protective role here to prevent the voltage from being too high in case of circuit failure, thereby limiting the load current and protecting the load from being burned by the current.

[0125] A specific embodiment of the voltage negative feedback control unit of the present invention:

[0126] In the voltage negative feedback control unit, according to the characteristics of the operational amplifier, the voltage at pin 5 of the inverter U2B is equal to the voltage at pin 6. Therefore, the inverter U2B outputs a voltage to control the conduction of the high-power triode Q1, making VOUT = VIN. In the voltage input unit, by setting the voltage of VSET, the voltage range of VIN is 2.5V < VIN < 6.5V. Therefore, the voltage range of VOUT is also 2.5V < VOUT < 6.5V.

[0127] A specific embodiment of the current sampling and detection unit of the present invention:

[0128] In the current sampling and detection unit, the voltage across the sampling resistor R16 is amplified by two stages to obtain VMNT.

[0129] In the first-stage amplifier circuit of this embodiment, from Va / R9 = (Vf - Va) / R15 and R9 = 10*R15, we get Va = 10*Vf / 11. From (Vc - vb) / R19 = (Vb - Vg) / simulated load R20 and R19 = 10*simulated load R20, we get Vg = (11*Vb - Vc) / 10 = (10Vf - Vc) / 10, that is, Vc = 10(Vf - Vg). The first-stage operational amplifier amplifies the voltage across the sampling resistor R16 by 10 times.

[0130] In the second-stage amplifier circuit, similarly, we can calculate that Ve = VMNT = 2*Vc = 20*(Vf - Vg). The total current I flowing through the load is I = VMNT / 0.1. By the AD detection of the MCU, VMNT can be obtained, and thus the current value of the load can be obtained. How much the working current of the load is expected to be can be set by the current detection feedback of VMNT to the set VSET voltage.

[0131] A specific embodiment of the threshold current setting unit of the present invention:

[0132] In the threshold current setting unit, a small constant current source is designed, and the current is set by BVIN. Similarly, according to the calculation formula of the operational amplifier amplification factor, we get Vh = 1 / 2BVIN. D5 also plays a protection role here to prevent the threshold current from being too large. In the voltage negative feedback circuit composed of Q2 and the inverter U2A, we know that Ib = BVIN / simulated load R29.

[0133] Since semiconductor lasers have a threshold current, and the threshold currents of different models of lasers vary greatly, generally ranging from a dozen milliamperes to several hundred milliamperes, a threshold current setting unit needs to be set. For example, a laser needs 100mA to start emitting light. In order to enable the laser to have a better high-frequency modulation characteristic, the threshold current can be set to 100mA.

[0134] A specific embodiment of the high-frequency signal modulation unit of the present invention:

[0135] In the high-frequency signal modulation unit, a resistor analog load R26 and an analog load R27 are connected in parallel to the MOS transistor M1. The purpose is to provide a bias current for the MOS transistor, so that the high-frequency switching characteristics of the MOS transistors M1 and M2 are better. U5 and U6 are two MOS transistor drivers, which can control the switching of MOS at high speed. The MOS transistor driver U4 is an inverter, so that only one of the MOS transistors M1 and M2 is conducting at the same time. This ensures that the operation of the load and the analog load are mutually exclusive.

[0136] A specific embodiment of adding an analog load in the present invention:

[0137] Since semiconductor lasers are used in parallel in multiple paths in actual applications, an additional path of analog load is required. Taking this embodiment as an example, the working voltage drop of the load semiconductor laser is about 2V. Then the maximum load current I = (6.5 - 2 - 0.3) / (3 + 0.1) + Ib = 1.35A + Ib (0.3 is the on-voltage drop of the MOS transistor).

[0138] If 100 such semiconductor lasers work simultaneously and the modulation signals are not synchronized, then the total working current of the circuit is very large, and the voltage drop of the wire cannot be ignored. Therefore, the voltage drop of the wire will affect the accuracy of the sampled voltage. Moreover, such a large current high-frequency switch also poses a huge challenge to the impact resistance, tolerance and performance of the power supply.

[0139] The use of an analog load in the present invention solves this problem well. The working current switches back and forth between the load and the analog load, ensuring the stability of the overall working circuit current. Although the voltage drop of the wire cannot be eliminated, once the working current is set, the voltage drop is constant, so the voltage of the sampling circuit will also be stable and will not affect the balance of each load current. There will also be no large impact on the power supply.

[0140] The current source control circuit designed by the present invention, especially in the field of semiconductor laser plate-making, reduces the manufacturing cost and difficulty, and well stabilizes the control of the output light intensity energy of the laser. Semiconductor laser plate-making requires multiple high-power lasers to work simultaneously, and be able to randomly control high-frequency switching, while also ensuring the balance and stability of the output laser energy.

[0141] The present invention provides a method to control a high-frequency controlled current source without expensive high-frequency operational amplifiers and high-frequency MOS transistors. Using ordinary devices can achieve the control of a high-frequency controlled current source, and can stably output current, and this current can be high-frequency switched, improving the output current adjustment range of the current source, and at the same time being very convenient to apply to various actual situations.

[0142] Especially in the case where multiple current devices are used in parallel and random high-frequency switching is required, it avoids the interference of wire voltage drop caused by large current. The present invention is particularly applicable to the control and modulation of high-power semiconductor lasers.

[0143] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. Although the present invention has been described in detail with reference to the above embodiments, those of ordinary skill in the art should understand that: modifications or equivalent substitutions can still be made to the specific implementation manners of the present invention, and any modification or equivalent substitution that does not depart from the spirit and scope of the present invention should be covered within the protection scope of the claims of the present invention.

Claims

1. A high-frequency controlled constant current source control circuit, characterized in that it includes a voltage input unit, a voltage negative feedback control unit, an analog load unit, and a high-frequency signal modulation unit; The voltage input unit is provided with an operational amplifier U1A and an operational amplifier U1B; The operational amplifier U1A and the operational amplifier U1B are connected in parallel to control the working current of the constant current source; The voltage negative feedback control unit is provided with an operational amplifier U2B and a triode Q1; The operational amplifier U2B and the triode Q1 are connected in series for voltage feedback control; The analog load unit is provided with an analog load for load simulation; The high-frequency signal modulation unit is provided with an inverter U2, a MOS transistor driver U3, a MOS transistor driver U4, a MOS transistor M1, and a MOS transistor M2 for high-frequency signal modulation; The inverter U2, the MOS transistor driver U3, and the MOS transistor M1 are connected in series; The MOS transistor driver U4 and the MOS transistor M2 are connected in series; During operation, the analog load unit is connected in parallel with the actually working load, and the working states are mutually exclusive, and the working state of the load is modulated by the high-frequency signal modulation unit. During high-frequency modulation, the current switches back and forth between the load and the analog load.

2. The high-frequency controlled constant current source control circuit according to claim 1, characterized in that A capacitor C1 and a resistor R2 are connected in parallel to the operational amplifier U1B, and a resistor R7 is connected in series; The positive input terminal of the operational amplifier U1B is sequentially electrically connected to a resistor R6 and a capacitor C5, and its negative input terminal is electrically connected to a resistor R5; A capacitor C9 and a resistor R10 are connected in parallel to the operational amplifier U1B, and a resistor R13 is connected in series; The positive input terminal of the operational amplifier U1B is electrically connected to a resistor R14, and its negative input terminal is electrically connected to a resistor R18.

3. The high-frequency controlled constant current source control circuit according to claim 1, characterized in that The positive input terminal of the operational amplifier U2B is electrically connected to R7 of the voltage input unit, its negative input terminal is electrically connected to the analog load, and its output terminal is connected in series with a resistor R1; One branch of the resistor R1 is electrically connected to a capacitor C2, and the other branch is connected to the base of the triode Q1; One branch of the emitter of the triode Q1 is connected to the load, and the other branch is connected to a first group of polarized capacitors; One branch of the collector of the triode Q1 is connected to the load voltage, and the other branch is connected to a second group of polarized capacitors.

4. The high-frequency controlled constant current source control circuit according to claim 1, characterized in that The first group of polarized capacitors includes a polarized capacitor C6 and a capacitor C7; The polarized capacitor C6 and the capacitor C7 are connected in parallel and grounded; The second group of polarized capacitors includes a polarized capacitor C4 and a capacitor C3; The polarized capacitor C4 and the capacitor C3 are connected in parallel and grounded.

5. The high-frequency controlled constant current source control circuit according to claim 1, characterized in that The analog load is a resistor or / and a diode group; The diode group includes a diode D2 or / and a diode D3 or / and a diode D4.

6. The high-frequency controlled constant current source control circuit according to claim 1, characterized in that The MOS transistor M1 is connected in parallel with a first filtering unit; The first filtering unit includes a capacitor C13 and a resistor R26; The capacitor C13 and the resistor R26 are in parallel; The MOS transistor M2 is in parallel with a second filtering unit; The second filtering unit includes a capacitor C14 and a resistor R27; The capacitor C14 and the resistor R27 are in parallel.

7. A high-frequency controlled constant current source control circuit according to any one of claims 1-6, characterized in that A current sampling and detection unit is provided between the voltage negative feedback control unit and the high-frequency signal modulation unit; The current sampling and detection unit is provided with an operational amplifier U3A, an operational amplifier U3B, and a resistor R16; The operational amplifier U3A, the operational amplifier U3B, and the resistor R16 are connected in series for current sampling and detection; A threshold current setting unit is provided between the current sampling and detection unit and the high-frequency signal modulation unit; The threshold current setting unit is provided with a zener diode D5, a triode Q2, an inverter U2A, and a constant current source BVIN; One end of the zener diode D5 is connected to the positive input terminal of the inverter U2A, and the other end is grounded; The triode Q2, the inverter U2A, and the constant current source BVIN are connected in series in sequence for threshold current control.

8. A high-frequency controlled constant current source control circuit according to claim 7, characterized in that The operational amplifier U3A is in parallel with a capacitor C8 and a resistor R8, and is in series with a resistor R12; The positive input terminal of the operational amplifier U3A is electrically connected to a resistor R17, and its negative input terminal is electrically connected to a resistor R11; The operational amplifier U3B is in parallel with a capacitor C11 and a resistor R19; One branch of the positive input terminal of the operational amplifier U3B is electrically connected to a resistor R9 and a capacitor C10, and the other branch is connected to a resistor R15; The negative input terminal of the operational amplifier U3B is electrically connected to a resistor R20; The emitter of the triode Q2 is connected to the resistor R29, its collector is in series with a resistor R21 and an inductor L1, and its base is electrically connected to the resistor R24; Resistors R22, R23, R25, and a capacitor C12 are provided between the inverter U2A and the constant current source BVIN.

9. A high-frequency controlled constant current source control circuit, characterized in that It includes a voltage input unit, a voltage negative feedback control unit, an analog load unit, a current sampling and detection unit, a threshold current setting unit, and a high-frequency signal modulation unit; The voltage input unit is provided with an operational amplifier U1B and an operational amplifier U1A; The operational amplifier U1B and the operational amplifier U1A are in parallel for controlling the working current of the constant current source; The voltage negative feedback control unit is provided with an operational amplifier U1 and a triode Q1; The operational amplifier U1 and the triode Q1 are connected in series; The analog load unit is provided with an analog load; The current sampling and detection unit is provided with an operational amplifier U3A, an operational amplifier U3B, and a resistor R16; The operational amplifier U3A, the operational amplifier U3B, and the resistor R16 are connected in series for current sampling and detection; The threshold current setting unit is provided with a zener diode D5, a triode Q2, an inverter U2A, and a constant current source BVIN; One end of the zener diode D5 is connected to the positive input terminal of the inverter U2A, and the other end is grounded; The triode Q2, the inverter U2A, and the constant current source BVIN are connected in series in turn for threshold current control; The high-frequency signal modulation unit is provided with an inverter U2, a MOS transistor driver U3, a MOS transistor driver U4, a MOS transistor M1, and a MOS transistor M2 for high-frequency signal modulation; The inverter U2, the MOS transistor driver U3, and the MOS transistor M1 are connected in series; The MOS transistor driver U4 and the MOS transistor M2 are connected in series; During operation, the analog load unit is connected in parallel with the actually operating load, and the operating states are mutually exclusive. The high-frequency signal modulation unit modulates the operating state of the load, and the current switches back and forth between the load and the analog load during high-frequency modulation.

10. A laser driving circuit, characterized in that An high-frequency controlled constant current source control circuit as described in any one of claims 1-9 is applied.

Images