HALF-BRIDGE MOSFET SWITCH FOR LASER DIODES

Purpose

Creating a PWM key to control a semiconductor laser with consumption currents up to 8 amperes.

Specifications

• Power supply 10-20 V
• Logic zero level <0.3 V
• Level of logical unit> 3 V
• Log in consumption <10 μA
• Output current (depends on the type of power source) 8 A

Description

The scheme is based on the common half-bridge IR2104 driver. The chip control can be carried out by CMOS or TTL levels and can control n-channel MOSFET or IGBT transistors.
The microcircuit is turned on according to the scheme recommended by the manufacturer.

It should be noted that the circuit should not be controlled by pulses with 100% filling, or by continuous supply of a high logic level to the control input, otherwise the bootstrap capacitor will not be able to charge through the low-side transistor while the upper-side transistor is closed, which will lead to incomplete opening of transistors, significant overheating and voltage drop across the load.

The approximate layout on the PCB.