W
wolti_At
Hello,
I am looking for some advice for controlling an N-channel MOSFET
(IPD64CN10N). Right now for testing I was using an IR2112 driver which
I already had available and a small isolation transformer. I do not
like this because this is a) quite expensive and b) a not so elegant
solution. My application is special in the case that the source of the
MOSFET does not stay on a constant potential - instead its source
might change between -24V and 24V referenced to ground. This voltage
is constant with respect to the switching times of the MOSFET(100kHz).
The input voltage available is +24V. I have investigated the following
solutions:
a) Using a charge pump would allow me to generate a voltage above the
positive supply rail to control the MOSFET. The main problem I see is
that at the lower end of the operating point I would end up with a to
high gate-source voltage and would destroy the MOSFET. Adding a zener
in series to the gate would solve this problem but would add an extra
and high load to the charge pump.
b) Use a small DC/DC converter with proper isolation. In this case
driving the mosfet is simple but the costs are high.
c) I can not use the standard bootstrap methods provided for example
by the IR2112 driver because I have no way to charge the bootstrap
capacitor when the MOSFET is turned off.
Thanks for all possible input,
Christian
I am looking for some advice for controlling an N-channel MOSFET
(IPD64CN10N). Right now for testing I was using an IR2112 driver which
I already had available and a small isolation transformer. I do not
like this because this is a) quite expensive and b) a not so elegant
solution. My application is special in the case that the source of the
MOSFET does not stay on a constant potential - instead its source
might change between -24V and 24V referenced to ground. This voltage
is constant with respect to the switching times of the MOSFET(100kHz).
The input voltage available is +24V. I have investigated the following
solutions:
a) Using a charge pump would allow me to generate a voltage above the
positive supply rail to control the MOSFET. The main problem I see is
that at the lower end of the operating point I would end up with a to
high gate-source voltage and would destroy the MOSFET. Adding a zener
in series to the gate would solve this problem but would add an extra
and high load to the charge pump.
b) Use a small DC/DC converter with proper isolation. In this case
driving the mosfet is simple but the costs are high.
c) I can not use the standard bootstrap methods provided for example
by the IR2112 driver because I have no way to charge the bootstrap
capacitor when the MOSFET is turned off.
Thanks for all possible input,
Christian