So, I've been playing around with PWM, and I would like to have one PWM channel drive a buck circuit and another channel drive a boost circuit.
The magnetics that I am looking to use would like to be driven in the 100-150khz range. Mosfets to drive this are not a dime a dozen, but perhaps $10/dozen. I've read other places that the PWMs can have a base frequency as high as 1.6Mhz? Currently I'm using P9_14 to drive the input of an oscilloscope which is 1Mohm-15pf and the wave form looks like slow capacitor charging. When I model the slope on spice it looks like the output impedance of P9_14 might be in the 50-70kOhm range? This means that I can't create a crisp pwm signal at any where near the frequency I'm hoping for. Also, this would mean that the maximum current out of a pin at 3.3v would be 0.06mA... and that has got to be wrong as I have seen too many warnings to limit source/sink current to 6mA or less??? Any ideas what I might be doing wrong that is limiting my pwm max frequency so badly? Thanks, Bill -- For more options, visit http://beagleboard.org/discuss --- You received this message because you are subscribed to the Google Groups "BeagleBoard" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. For more options, visit https://groups.google.com/d/optout.
