Victor 884 output decoding / General question

[theshadow27]

I have a pretty basic understanding of PWM h-bridges like the 884, that there are P and N MOSFETs that control the flow of current forward and backward through the motor. In terms of operation, the proper P channel FET is switched on, letting Vbatt get to the motor. Then, a PWM signal is applied to the faster N channel FET, who's source gate is connected to Vss. By varying the pulse width of the signal, you can control the motors speed, from 0%/100% which is coast to 100%/0% which is full. Additionally, if both P or both N FETs are turned on at the same time, the motor's coils are shorted and the motor slows down rapidly (brake).

Now my question is: How would you go about decoding the output of an existing H-Bridge (with out modifying it) to drive an additional, discrete (possibly larger ) MOSFET H-Bridge on a shared ground plane?

(note: NOT for our FRC robot)

Well here is where I am so far... My gut reaction was to slap an 8 bit PIC in with some diodes, run a timer to decode the PWM and spit it out on another pin. Stumbling around on the internet, I found a very interesting example of using 2 AND gates (74 series logic) to prevent accidental shorting of the shared terminal FETs together (here). From this circuit I was able to eliminate the need for the PIC, however I was left with a bulky and awkward network of bipolars, pull-ups, and diodes before the gates. The chip I have been working with is a 74AC11008 quad AND gate from TI.

So, does any one have any "Duh" ideas that I have totally missed because I have been staring at this for the last 36 hours? I also tend to over-complicate things, and I am sure there is a very simple solution...

Thanks all!

JD