The schematic is
The wave form is as follows, yellow line is channel 1 which is gate voltage and blue line is channel 2 which is drain voltage.
The 148kHz PWM signal is totem pole output of UC3845, MOSFET is n-type (IRFZ44N) and 12.4V power.
The drain voltage drops fast when gate voltage is on, but it increase very slowly (about 2.5us) when gate voltage is off. If I replace the 1K resistor with lower value, the Vd increase faster. But this means more power consumption.
- Why Vd increase slowly?
- For the speed up of Vd increase, is there any other way than decreasing Vd resistor(1K)?