I designed a simple buck converter to meet the following specs (I have attached the schematic):
- Vin = 17.4V
- Vout = 12V
- D = 0.69
- Switching Frequency = 50kHz
- Inductor Ripple Current = 20% of Output Current
- Output Voltage Ripple = 2% of Vout
Background Info: All the parts and component values listed on the schematic are parts I'm implementing in the circuit. I know the inductor and capacitor values are not matched perfectly to the specs listed above, but they are the closest that I could find. The PWM signal is being generated by the Arduino Uno and I am using the TC4427 IC to drive the signal at the gate of my MOSFET.
Problem:My MOSFET is not turning on. I know for it to turn on Vgs > Vth. I am using the TC4427, because the max output voltage of the Arduino is only 5V. What I'm confused about is why my gate driver isn't supplying the necessary turn on voltage. I thought I understood how it works, but not apparently. The max output of the TC4427 is only as high as the supply voltage I feed into it (from measurements I've taken), which doesn't make sense to me. I've looked on the TC4427 datasheet, but it doesn't give me any information on the max voltage output coming from the gate driver. Does this mean I need to supply an input volts higher than V1 to the supply just to turn on my MOSFET? Or how exactly is a gate driver supposed to work?