Hi,
Background: Trying to understand how a BLDC motor controller works. The system would comprise a microcontroller generating the PWM signals (6 of them, one for each MOSFET), which would be fed to three IR2110 MOSFET drivers using a synchronous rectification (active freewheeling) drive schema. (the microcontrolles handles the deadtime problem). It would be using high and low N-Channel MOSFET.
I have been struggling to understand how is it possible, for a MOSFET driver IC (IR2110 for instance) to effectively activate a low-side N-Channel MOSFET whenever it is handling the freewheeling current from the motor. As I understand, MOSFETs can conduct from Drain to Source as well as from Source to Drain provided the device is "on", ok, but... in this particular moment the source of the transistor would be higher than ground so, in order for the IR2110 to provide enough gate voltage, it would have to generate voltages greater that the Vcc (Low side supply), isn´t it?. I can´t see how can that happen, what am I missing?.
Background: Trying to understand how a BLDC motor controller works. The system would comprise a microcontroller generating the PWM signals (6 of them, one for each MOSFET), which would be fed to three IR2110 MOSFET drivers using a synchronous rectification (active freewheeling) drive schema. (the microcontrolles handles the deadtime problem). It would be using high and low N-Channel MOSFET.
I have been struggling to understand how is it possible, for a MOSFET driver IC (IR2110 for instance) to effectively activate a low-side N-Channel MOSFET whenever it is handling the freewheeling current from the motor. As I understand, MOSFETs can conduct from Drain to Source as well as from Source to Drain provided the device is "on", ok, but... in this particular moment the source of the transistor would be higher than ground so, in order for the IR2110 to provide enough gate voltage, it would have to generate voltages greater that the Vcc (Low side supply), isn´t it?. I can´t see how can that happen, what am I missing?.