PoyntExH
Mechanical
- Jan 14, 2013
- 14
Hi all. I am using a 1200v 400a igbt to drive a large pulsed soleniod with a single pulse with a pulse width of about 3 milliseconds. When in use, the solenoid is only pulsed once every few minutes. Current in the pulse is usually about 400A.
What I want is to make or use a simple driver with enough output current that can switch it on fast enough to minimize the switching losses that I know I must be having with the setup I'm using.
Here is the datasheet for my IGBT:
I do not know much about mosfet and IGBT gate driving, other than the basics. I know the driver needs to have enough available current in order to charge up the gate capacitance quickly enough to switch it on without significant losses. I know that this current is only needed for a few nano seconds or so, and I know that the current required is based on the drive voltage and the gate resistor. Since my gate resistor is 2.7 ohms, if I want to drive it with 15 volts I'll need around 5.5 amps to charge up the 26 nF gate.
Right now I am firing the gate with 17 volts from an lm7555 timer in one-shot configuration. (this is the improved cmos version of the classic lm555 timer) The problem with the 7555 is that it can only output 100mA of current, so I know that I am causing a much slower turn-on than what the igbt would normally like. (I can also see it on my oscilloscope) I was thinking of designing some sort of output buffer to put on the output of that 7555, maybe using a fast high current op-amp buffer, (if I can actually find one) though I know this is probably isn't a very good way to do this.
I know that there are a multitude of igbt gate drive IC's out there, but I know next to nothing about them and I've found no information on how to set up and use one for a one-shot firing of the igbt.
Thanks,
-Rob
What I want is to make or use a simple driver with enough output current that can switch it on fast enough to minimize the switching losses that I know I must be having with the setup I'm using.
Here is the datasheet for my IGBT:
I do not know much about mosfet and IGBT gate driving, other than the basics. I know the driver needs to have enough available current in order to charge up the gate capacitance quickly enough to switch it on without significant losses. I know that this current is only needed for a few nano seconds or so, and I know that the current required is based on the drive voltage and the gate resistor. Since my gate resistor is 2.7 ohms, if I want to drive it with 15 volts I'll need around 5.5 amps to charge up the 26 nF gate.
Right now I am firing the gate with 17 volts from an lm7555 timer in one-shot configuration. (this is the improved cmos version of the classic lm555 timer) The problem with the 7555 is that it can only output 100mA of current, so I know that I am causing a much slower turn-on than what the igbt would normally like. (I can also see it on my oscilloscope) I was thinking of designing some sort of output buffer to put on the output of that 7555, maybe using a fast high current op-amp buffer, (if I can actually find one) though I know this is probably isn't a very good way to do this.
I know that there are a multitude of igbt gate drive IC's out there, but I know next to nothing about them and I've found no information on how to set up and use one for a one-shot firing of the igbt.
Thanks,
-Rob