Constant current source power supplying circuit of laser

Abstract

The invention discloses a constant current source power supplying circuit of a laser, which is mainly used in the field of tunable laser and is capable of providing a highly stable power supplying current of a laser. The constant current source power supplying circuit comprises a voltage controlled input end, a voltage controlled constant current source circuit, a current output end, and a positive feedback circuit, wherein the positive feedback circuit includes a voltage follower, an input end of the voltage follower is connected with the current output end, an output end of the voltage follower is connected with a non-inverting input end of a first operational amplifier. A control voltage is inputted from the voltage controlled input end, the magnitude of the power supplying current of the laser outputted by the current output end is controlled through the voltage controlled constant current source circuit, when the control voltage jumps, the voltage of the non-inverting input end of the first operational amplifier is controlled by the power supplying current through the positive feedback circuit for a smooth transition in the direction of the control voltage. Under the action that a negative feedback speed of the voltage controlled constant current source circuit is faster than a positive feedback speed of the same, the power supplying current changes to a current value setby the control voltage smoothly.

Description

technical field [0001] The invention relates to a power supply circuit, in particular to a constant current source power supply circuit of a laser. Background technique [0002] In the field of adjustable lasers, it is necessary to provide a stable and high-precision current source for the laser. The output of the current source cannot have a large current impact, and it must be able to monitor the abnormality of the current source and collect the current calibration data of the current source. [0003] In the prior art, such as figure 1 The circuit shown provides an adjustable constant current for the laser. The laser constant current source circuit includes a voltage-controlled constant-current source circuit 1, a charge-discharge circuit 2, and a monitoring circuit 3; the voltage-controlled constant-current source circuit 1 is mainly composed of an operational amplifier U1- A and MOS tube U4 form a commonly used voltage-controlled constant current source circuit, from th...

AI Technical Summary

Problems solved by technology

[0004] figure 1 The laser constant current source circuit shown has the following defects: when the control voltage input by the voltage control input terminal VSET jumps, the capacitor C1 is charged or discharged too quickly because of the large voltage value change, thereby forming a large current, which is affected by It controls the power supply current output by the laser constant current source circuit. There will be an overshoot and callback process. The laser as a load will be impacted by a large current, which will affect the performance of the laser.

Images