I plan to build a LED driver that can pulse a high-power LED (3W) down to the 100s of nanoseconds pulse regime, yet also allows longer pulses (up to 100ms) should be possible. The LED should be driven off a TTL/GPIO signal.
I’m admittedly a bloody beginner in electronics but did some reading upfront. I came to the following conclusions so far, which also might be wrong:
- buck/boost driver are too slow
- timer or avalanche circuits have fixed pulse width
- single mosfet driver can introduce oscillations
- my best bet is a push-pull mosfet driver
- shunt drivers might also be an option
Sadly, I haven’t found a comprehensive tutorial on designing such a driver specifically for driving high-power LEDs. If there is one I have overlooked I would be happy if someone could push me in the right direction. If there really is none, I have the following questions:
- Which transistor pair would be good to drive a 3W LED in push-pull?
- How do I calculate the resistors specifically for the LED (3.5V, 700mA)?
- What type of power supply can I use to drive the circuit? Are voltage regulators interfering in such circuits?
Independently from this: what do I need to do to step such a circuit up to drive a 30W LED?
As mentioned above I would be happy to read a existing tutorial about this if this is a repost!