At 07:02 PM 8/29/01 +0200, you wrote:
>Hi All,
>
>I was wondering if some of you guys happen to know a simple circuit to
>create a 1us (approx.) delay for a 20kHz PWM signal coming out of a
>PIC. I need this to create a death-time in order to avoid current
>shoot through in an H-bridge.
>
>The circuit I have right now consists of a small RC to slow down the
>ramps of the pulse, followed by a comparator with significant
>hysteresis. The comparator hysteresis is set at 1/3 and 2/3 of vdd.
>This circuit seems to work ok, but I was wondering if there were other
>options too. Or is my current approach not so bad after all?
>


A logic gate should also work in place of the comparator. Actually
I am surprised that simply inserting the RC in line to the h-bridge
alone does not do the job. Guess it depends upon the exact ckt.

- dan
============

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