Rakesh Menon
Newbie level 4
Hello,
I'm currently trying to build a range finder using NIR pulsed laser diode to achieve 100-150meters range. I'm planning to use four OSRAM's SPL PL90_3 Laser diodes ( https://www.mouser.com/ds/2/311/SPL PL90_3-461392.pdf ) to get ranges from different directions. I'm planning to use FPGA as the control system and the lasers should get alternaly pulsed every 2nS with an off time of around 2uS. After a lot of googling I found that lMG1020 can drive the GaN mosfet
( https://www.ti.com/product/LMG1020/technicaldocuments?dcmp=dsproject&hqs=td&#doctype2) as it would add only 2.5 nanoseconds of propogation delay and support 60MHz operation and this GaN mosfet will provide the current required for the laser to operate.
As I'm very much new to this laser-based designs, I am unable to relate the average power output and the range. Why do we need peak output power when average output power is considered? Can I directly connect the output of this Driver IC to GaN Mosfet's gate? How much voltage and current should I supply at the GaN mosfet source so that I will get maximum range ( I dont understand relation between range and power output ). If some one can tell me any additional things that needs to be considered while making this design, I would really appreciate that.
I'm currently trying to build a range finder using NIR pulsed laser diode to achieve 100-150meters range. I'm planning to use four OSRAM's SPL PL90_3 Laser diodes ( https://www.mouser.com/ds/2/311/SPL PL90_3-461392.pdf ) to get ranges from different directions. I'm planning to use FPGA as the control system and the lasers should get alternaly pulsed every 2nS with an off time of around 2uS. After a lot of googling I found that lMG1020 can drive the GaN mosfet
( https://www.ti.com/product/LMG1020/technicaldocuments?dcmp=dsproject&hqs=td&#doctype2) as it would add only 2.5 nanoseconds of propogation delay and support 60MHz operation and this GaN mosfet will provide the current required for the laser to operate.
As I'm very much new to this laser-based designs, I am unable to relate the average power output and the range. Why do we need peak output power when average output power is considered? Can I directly connect the output of this Driver IC to GaN Mosfet's gate? How much voltage and current should I supply at the GaN mosfet source so that I will get maximum range ( I dont understand relation between range and power output ). If some one can tell me any additional things that needs to be considered while making this design, I would really appreciate that.