Power supply adaptive control circuit

Abstract

The utility model discloses a power supply adaptive control circuit which comprises an operational amplifier, the output end of the operational amplifier is connected with the G pole of an MOS tube, the D pole of the MOS tube is connected with one end of a laser diode LD, and the other end of the laser diode LD is connected with the VOUT end of a DCDC chip. The power supply self-adaption increases the universality of the design to the laser, fundamentally reduces the heating problem of the system, improves the use stability of the laser, reduces the heating problem of the system, and reduces the aging and damage speed of the device.

Description

Technical Field

[0001] This utility model relates to the field of laser technology, specifically to a power supply adaptive control circuit. Background Technology

[0002] In the study of laser driver circuits, a constant current source is used to provide a constant driving current to the laser, enabling it to output stable optical power. For the laser driver circuit, the laser is equivalent to a load. The equivalent resistance of each laser is different, and the power supply voltage required for normal operation is also different. Furthermore, in the driver circuit of a high-power laser, the range of the required driving current increases accordingly, and the larger the range, the greater the required power supply voltage.

[0003] To ensure the stability of the laser's output power, the laser driver board needs to provide a stable drive current. For common operational amplifier and MOSFET-based constant current sources, the power supply voltage required in the drive circuit must meet the supply voltage required when the drive current is at its maximum. However, when the drive current is small, the voltage drop across the MOSFET will continuously increase, and its power loss will be converted into heat, greatly increasing the heat of the entire drive circuit. Since this drive circuit is designed to be compatible with the laser, which is a temperature-sensitive device, temperature has a significant impact on the stability of the output power and the shift in the center wavelength. As for the MOSFET itself, long-term operation in a high-temperature environment will accelerate its aging and damage, further exacerbating its performance degradation.

[0004] To address this, a power supply adaptive control circuit is proposed. Summary of the Invention

[0005] The purpose of this invention is to provide a power supply adaptive control circuit to solve the problems mentioned in the background art.

[0006] To achieve the above objectives, this utility model provides the following technical solution: a power adaptive control circuit, including an operational amplifier, the output terminal of which is connected to the gate of a MOSFET, the drain of the MOSFET is connected to one end of a laser diode LD, and the other end of the laser diode LD is connected to the VOUT terminal of a DC-DC chip;

[0007] An MCU controller is also connected to the drain (D) terminal of the MOSFET, and the FB terminal of the MCU controller is connected to the DC-DC chip.

[0008] Preferably, a sampling resistor is connected to the source (S) terminal of the diode.

[0009] Preferably, the negative input terminal of the operational amplifier is connected to the source terminal (S) of the MOSFET.

[0010] Preferably, the positive input terminal of the operational amplifier is connected to VSET.

[0011] Preferably: the D pole of the MOS tube is further connected with a resistance for voltage division between the MCU controller.

[0012] Compared with the prior art, the utility model has the beneficial effects that:

[0013] 1, power self-adaption increases the universality of the design to the laser.

[0014] 2, fundamentally reduce the heat problem of the system, improve the stability of the use of laser.

[0015] 3, reduce the system heat problem, reduce the speed of device aging and damage. BRIEF DESCRIPTION OF DRAWINGS

[0016] Figure 1 It is the circuit schematic diagram of the utility model. DETAILED DESCRIPTION

[0017] The technical scheme in the embodiments of the utility model will be described clearly and completely in combination with the drawings in the embodiments of the utility model.

[0018] Please refer to Figure 1 The utility model provides a kind of technical scheme: a power self-adaptive control circuit, including operational amplifier, the output of the operational amplifier is connected with the G pole of MOS tube, one end of laser diode LD is connected on the D pole of the MOS tube, the VOUT end of DCDC chip is connected on the other end of the laser diode LD;MCU controller is further connected on the D pole of the MOS tube, the FB end of the MCU controller is connected on DCDC chip.

[0019] As Figure 1 Shown: the S pole of the diode is connected with sampling resistance, and the input negative pole of the operational amplifier is connected to the S pole of the MOS tube.

[0020] As Figure 1 Shown: the input positive pole of the operational amplifier is connected with VSET;Through the above setting, the voltage is set by VSET to make LD output the drive current value that LD wants to work.

[0021] As Figure 1 Shown: the D pole of the MOS tube and MCU controller are further connected with resistance for voltage division;Through the above setting, the voltage of the D pole of the MOS tube is input into MCU controller by resistance voltage division.

[0022] Working principle: the voltage is set through VSET to make the laser diode LD output the driving current value that the laser diode LD wants to work. At this time, the MOS tube works in the linear region, and the resistance value between the D pole and the S pole will change according to the driving current. The voltage at the D pole is divided through the resistance and input into the MCU controller, and the MCU controller adjusts the FB pin of the DCDC chip according to the characteristics of the MOS tube and the voltage drop required by the driving current of the MOS tube, so as to change the output voltage of VOUT, so that the DCDC output is at the minimum driving voltage of the current driving current. Improve the utilization rate of power supply voltage, and reduce the heating problem of MOS, and the resistance value between D and S changes corresponding to different temperatures, that is, the voltage changes.

[0023] Although the embodiments of the utility model have been shown and described, it can be understood by those skilled in the art that various changes, modifications, replacements and variations can be made to these embodiments without departing from the principles and spirits of the utility model, and the scope of the utility model is defined by the appended claims and their equivalents.

Claims

1. A power supply adaptive control circuit comprising an operational amplifier, characterized by: The output end of the operational amplifier is connected with the G pole of a MOS tube, one end of a laser diode LD is connected on the D pole of the MOS tube, and the VOUT end of a DCDC chip is connected on the other end of the laser diode LD. The D pole of the MOS tube is also connected with an MCU controller, and the FB end of the MCU controller is connected on the DCDC chip.

2. A power supply adaptive control circuit according to claim 1, wherein: The S pole of the diode is connected with a sampling resistor.

3. The power supply adaptive control circuit of claim 1, wherein: The input negative pole of the operational amplifier is connected with the S pole of the MOS tube.

4. The power supply adaptive control circuit of claim 1, wherein: The input positive pole of the operational amplifier is connected with VSET.

5. The power supply adaptive control circuit of claim 1, wherein: The D pole of the MOS tube and the MCU controller are also connected with a resistor for voltage division.

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