Question
What is the best way to minimize electrical noise in the driver output current when using the WLD Laser Driver?
Answer
The WLD Series Laser Drivers are a 100% analog devices which do not do a great deal of filtering of the supply voltage, so it is necessary to use a voltage supply that offers the noise and ripple specifications that are appropriate to the application. Power supply selection is critical in minimization of the amount of noise and ripple achived in a laser driver system. There are two basic types of power supplies; linear and switching. A linear supply will generally provide a supply voltage that has less noise and ripple than a switching power supply. To achieve the lowest possible noise and ripple in the driver output current, your application may require a very “clean” linear power supply. For more information regarding power supplies, please see the Power Supply Basics page.
If using the heat sink mounted fan on the WLD for thermal protection, be sure to attach the supplied grounding strap wire to the heat sink in order to help minimize the motor noise from the cooling fan.
Wiring can also introduce noise into the diode current. Always attempt to keep wire runs as short as possible, and routed away from any strong EMF forces such as an AC line or motor wiring. Twisting the lead wires to the laser diode may also help minimize noise ingress.
An attention to standard low noise signal grounding procedures such as star grounding will also help minimize system noise being transferred to the laser diode current.