> > What is the minimum voltage I should have on the GPIO input so it is read > as 1 logic? > > > For most CMOS the minimum input voltage guaranteed to be read as a one is 0.7 times Vcc.
But not always. Read the spec sheet for the part in use. For instance, the transmission gate you found was rated for Vcc of 5 V , but said that the gate control was compatible with both 5V and 3.3V systems, which tells me the Voltages are offset from standard. > > I guess that I have to take the maximum current sink a GPIO can handle? I > cant find these values - only current source (4mA). Can I find the same > value for current sink? > > Normally CMOS can sink more current than it can source, typically by a factor of about three, if the device designer used the same geometries for the pull up and pull down transistors. But not always. They could have used a smaller geometry for the sinks. As usual, read the data sheet. If you can't find the sink current, then I think you must assume it is the same, in this case 4 mA. --- Graham == -- 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 beagleboard+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.
