tips to design a fast switching circuit

[EETT]

Hi,

I'm looking for some tips to design a fast switching circuit
My Input: 0V-15V Supply, 0-5V TTL Pulse Train of .5K to 25KHz
My Load: 0-15V, Max 15A
My Output: 0-15V Pulse Train of .5 to 25KHz

I've tried several designs my problems are
1. can't handle higher current than 3A,
2. too much heat generation
3. aren't fast enough

Please help

 

[melone]

I'm confused by your specs.... The input could be 0V and the output must be a 15V / 15A pulse train? What the heck is the final application?

 

[EETT]

Sorry,
1. for cross posting
2. vague spec

My output has to be a square wave 0 to Max(100%) = input V supply, frequency = frequency of input pulse train.
This application is to drive a pump at high V high C and
as quick as 25 KHz

 

[itsmoked]

Just use a low R_ds FET and a FET driver to make sure the FET doesn't hang around in 'linear land' for long. Some FET drivers can also provide overload protection. Your voltage considerations are mundane and covered by all FETS and drivers.

Keith Cress
Flamin Systems, Inc.-

http://www.flaminsystems.com

 

[DCLabs]

Use an IRFZ44 MOSFET (International Rectifier) and HIP2101 driver (Intersil). Heatsink the Mosfet as it will dissipate around 3 watts at 50% duty cycle. I assume the pressure is variable per the 0 to 100% duty cycle spec. I am little confused why you would vary the output voltage. Why not adjust the PW to vary pressure ?