The "standard cheap" way to make a 1 PPS 50-ohm output is to use a 74ACT04 hex inverter chip powered by 5V. The chip is specified for 24 mA from each output pin. Connect 5 inputs together to your PPS signal. Run each of the 5 outputs through a 220 ohm series resistor, then tie them together as your PPS output. This will drive about 2.4 volts into a 50-ohm load, with crisp edges. It will easily trigger most instruments.
The chip is specified up to 6V supply voltage, so you can get an output pulse of almost 3V if you have a 6V rail in your design. You can use the sixth inverter as your PPS input, with two paralleled 100-ohm resistors as the load (and ESD guard) at its input pin. The switching point for the 'ACT version of the chip is around 1.4V, so the 2.4V output signal will easily drive it. This circuit may not be perfect, but it shows up in a lot of professional gear. Cheers! --Stu _______________________________________________ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.