pwm controller chip

[onceinalifetim]

currently am doing a project on switching on and off on IGBT.. need to design the control circuit to send the pulse to IGBT..
i will be using PWM controller chip, requirement for the chip, the supply voltage will be 15v. frequency 20khz and duty cycle will be 50%.
my problem is, how to reduce the rise time and fall time but the output voltage is 15v??
i went to search all the pwm controller chip, it doesn't tell me about the rise time timing etc etc.. any pwm controller chip to intro me??? pls

 

[(*steve*)]

Why would you want to reduce the rise and fall time of the signal? Generally the goal is to increase the switching speed, not reduce it.

In general, limiting the current to the gate of the IGBT will result in slower switching.

 

[Gryd3]

Why would you want to reduce the rise and fall time of the signal? Generally the goal is to increase the switching speed, not reduce it.

In general, limiting the current to the gate of the IGBT will result in slower switching.

I think perhaps the op was referring to the slew rate of the controllers. Although I think that without having a scope, and some working experience with it, the op may end up with a sub-optimal slew rate from stray capacitance and inductance in the remainder of the circuit and leads that will be used.

@onceinalifetim , can you please confirm what you may have for a 'goal' for your device?
I'm sure a solution can be found, but it will be much more expensive than you thought if one is found with the best ever possible parameters.
Finding one that fits your application will fit in your possible budget much nicer.

 

[BobK]

The rise time and fall time will depend on the gate capacitance of the IGBT and the current capability of the gate driver. Are you using a gate driver chip? If not, you probably should be.

Bob