input resistor for VB921
Posted: Tue Aug 08, 2006 10:55 am
In here http://megasquirt.sourceforge.net/extra ... wheel.html
I see two values shown for the input resistor on the VB921. Anyone know for sure if the right value is 330 or 680 Ohm, or even if it matters? It seems to work on the bench with either but I would rather not find out I got the wrong one on a rainy night in northern england. Looking at the data sheet for the chip I'm not convinced it needs a resistor at all as it is logic driven and "requires no external components" but I would be guided by anyone with some experience of this setup.
Jon
I see two values shown for the input resistor on the VB921. Anyone know for sure if the right value is 330 or 680 Ohm, or even if it matters? It seems to work on the bench with either but I would rather not find out I got the wrong one on a rainy night in northern england. Looking at the data sheet for the chip I'm not convinced it needs a resistor at all as it is logic driven and "requires no external components" but I would be guided by anyone with some experience of this setup.
Jon