jtexas said:
right, I don't need to drive a driver, just a driver to accept a PWM signal. Battery voltage will generally range from 12.65 to 12.25 but never less than 10.6 or more than 14.
your circuit looks like just the thing.
Just for clarity, are you saying a capacitor from Vbatt to ground...what about a resistor to discharge it when the motor is shut off?
If you wish, a 10Mohm resistor or something. But it's low voltage so I don't think it's needed (you aren't gonna die if you touch 12V).
My uncertainty is, in selecting components that won't crap out on me. Any recommendations there would be appreciated.
Thanks!
THese are the ones I will use on my motor driver of similar size:
Schottky Diode - Diodes Inc. - PDS1040
NMOS- International Rectifier - IRF1324S-7PPbF
NPN/PNP pair- Zetex - ZDT6718
Discrete NPN - Zetex - ZTX618 (thru hole), FMMT618 (surface mount)
Discrete PNP - Zetex - ZTX718 (thru hole), FMMT718 (surface mount)
NMOS Heatsink (if needed) - Aavid THermalloy - 7109D
Decoupling Cap For Gate Driver - .1uF-1uF-4.7uF? ceramic
Decoupling Cap For Motor Supply - Electrolytic 1000mF?
These components can tolerate up to 20V (limited by the BJTs and NMOS max gate voltage). But if you use a regulator to provide the "10-15V" to the NPN/PNPs, then the limit is 24V of the NMOS source-drain.
THe NMOS needs 10V or greater (gate can tolerate 20V max). So if the voltage range is as you state, then you can directly connect Vbatt to the gate "10-15V".