ADPD4100 driving laser diode instead of LEDs


Can I use laser Diode (LD) instead of LEDs with the ADPD4100?

If yes, please advise how and if you have an application note on that 


  • 0
    •  Analog Employees 
    on Nov 3, 2020 4:34 PM

    Hi Shimon,

    ADPD4100 LED driver is basically a current sink that is tunable between 0-200 mA with steps of ~1.6 mA through its registers, therefore ADPD4100 ensures the driver current that you set by registers to flow into the LED or whatever load you have (including a laser diode).

    1. As stated in the datasheet, you should ensure 3.6 V max LED driver pin voltage by providing enough voltage drop between the supply voltage and the pin. You could use overvoltage protection circuit with an NPN transistor described in the datasheet to ensure safe voltage on the ADPD4100 driver pin. 

    2. Some laser diodes have a minimum turn-on current. Please make sure to use a current that is greater than the minimum turn-on current.

    3. Obviously, ADPD4100 provides current pulses (square wave shape) on the order of us of time and tunable peak current from 0 mA up to 200 mA for a single driver with ~1.6 mA steps and 400 mA peak current for multiple drivers used in a timeslot, therefore, please make sure the laser diode you choose is suitable for the application.  

    We do not have an app note as this is very typical, but you can drive laser diode with ADPD4100 freely. Just make sure that you protect ADPD4100 driver pins from overvoltage.

    Best regards,