I want to be able to control 12V as well as 24V LED strips that will be used in a video recording environment (so high switching frequency). In a few bullet points I will explain the planned circuit:
- Power supply will be either 12V or 24V
- LED strip will be controlled with a MOSFET ('logic-level' IRLR7843 for example)
- MCU controls the MOSFET with a 3.3V PWM signal
- To ensure that 3.3v is available to the MCU regardless of the input voltage LM2596 is used
So the question is how to drive the MOSFET? My first thought was to drive the MOSFET directly form the MCU but the problem with that is that the switching frequency would be limited due to the gate capacitance. So I have to use a MOSFET driver. Since I have only 24V/12V and 3.3V available on the board I would have to do one of the following:
- Use a driver that has a minimum supply voltage of at least 3.3V to drive the MOSFET (not easy to find, on ebay or aliexpress at least)
- Use a secondary Step-Down Voltage Regulator that steps down 24V/12V to a more usable voltage (like 10V or something) that a more readily available drivers support.
- Use a different MOSFET that allows for a larger Gate-to-Source Voltage that I can drive with 24V/12V. And find a driver that supports 24V supply voltage.
Any other option?