I'm playing around with some switching mode power supply things. For this reason, I'd like to switch the input voltage with a microcontroller, from the PWM output or other output pins.
- Input voltage: 4V - 60V
- Switching input signal: 3.3V (LVTTL)
- Maximum switching speed: 50kHz - 1MHz (as high as I can easily get it)
- Required current tolerance: 1.5A or 15W
There is no supply voltage besides the 3.3V signal.
I am looking for suitable components to do this as simply as possible. For me, simple means as few components as possible, and as few requirements on both the inputs and outputs of the components - I do not wish to impose any driving requirements to the microcontroller, or restrictions on how the switch can be used, or similar things. But I'd want the components to be suitable for a high efficiency switching mode power supply.
I know it can be done with a combination of n-MOSFET and a p-MOSFET and a couple resistors. I know it can also be done with a gate driver IC and a n-MOSFET, although I have been unable to locate one that would only require 3.3V supply voltage (and a boost pin?). I know I do not want a solution that would force some minimum off-time rate on the MOSFET to charge a capacitor, but I might be convinced otherwise. In theory, the most direct solution would be a 3.3V compatible solid state relay or analog switch, but the actual solid state relays available do not seem very suitable.
But, primarily I am just interested in learning more about the problem space here and the possible solutions.
Clarifying schematic stolen from another question:
- Vin = 4V - 60V
- Controller = 3.3V signal, toggling at, for example, 250 kHz
- Q1 = the component, or the set of components I wish to find
So, strictly, the question is simply: what do I need in place of Q1?
(Note that this is just an example schematic, not exactly the sort of circuit that I wish to build.)