Unruh wrote: [] > OK, I will believe you. However since the driving voltage of the > garmin 18 is usually taken from the USB and is 5 V, the output PPS > voltage will be less than 5V. ( maybe 4.5) Does that make a > difference?
In my experience, no. Anything above about 3V should be OK. Taking an example at random, the LT1780/LT1871 http://www.linear.com/pc/productDetail.jsp?navId=H0,C1,C1007,C1016,P1654 http://www.linear.com/pc/downloadDocument.do?navId=H0,C1,C1007,C1016,P1654,D2520 the thresholds are given as: Low: 0.8V (minimum) 1.3V (typical) High: 1.7V (typ), 2.4V (maximum) Hysteresis: 0.1V (min), 0.4V (typ), 1.0V (max) Cheers, David _______________________________________________ questions mailing list [email protected] https://lists.ntp.org/mailman/listinfo/questions
