AVR-Chat

You can use the intrinsic diode in a MOSFET for a flyback diode, and 
many designs do.  However, depending upon what you are doing it will 
cause the MOSFET to heat up.  Most folks prefer to move that heating off 
the part and use an external flyback diode.  I've seen MOSFETs used in 
AC dimmer designs that count on that intrinsic diode, and there it is 
just a case of burn the energy as heat here or do it there.  Just make 
sure that you choose a MOSFET that is designed with a robust intrinsic 
diode - I'm not sure all of them are.

DLC

Ryan wrote:
> Wait a sec....
> 
> Looking at the datasheet for the IRL520, it shows a zener across the
> drain & source.  It says the diode forward voltage is 1.3 volts.  Does
> this mean anything more than that will be shorted to ground (in my
> schematic)?  If so, the polarity protection will work, and I don't
> need the extra diode (D2)....  Although it does say the D-S breakdown
> voltage is 100V, and I don't know that the solenoid won't create
> spikes above that...
> 
> Thanks in advance,
> 
> 
> --- In AVR-Chat@yahoogroups.com, "Ryan" <g_i_jim2000@...> wrote:
> Therefore, any spikes above 12V won't
> 
>>get shorted out.  Let me know if that makes sense, I can draw up a
>>quickie schematic addendum.
>>
>>Ryan
> 
> 
> 
> 
> 
> 
> 
> 
>  
> Yahoo! Groups Links
> 
> 
> 
>  
> 
> 
> 

-- 
-------------------------------------------------
Dennis Clark          TTT Enterprises
www.techtoystoday.com
-------------------------------------------------