Hi everyone!
The ADCMP600 is a fast comparator with TTL/CMOS compatible outputs (high = Vcc-0.4V, low = 0.4V). The output of this comparator needs to be conveyed over several meters (~3) of coax cable to a 50-ohm terminated NIM crate input. However, the NIM standard sets logic "0" at 0mA, and logic "1" at -16mA.
The million dollar question is: What is the best way of converting the voltage-mode TTL logic to the current-mode NIM logic? And how can I best ensure that the signal is transferred with its fast leading edge intact? The NIM crate in question is a fast timetagger, and so propagation delay jitter in the logic level converter/line driver/coax cable is of importance and must be less than 1ns. The total propagation delay does not matter, only jitter does.
I look forward to your suggestions!
The ADCMP600 is a fast comparator with TTL/CMOS compatible outputs (high = Vcc-0.4V, low = 0.4V). The output of this comparator needs to be conveyed over several meters (~3) of coax cable to a 50-ohm terminated NIM crate input. However, the NIM standard sets logic "0" at 0mA, and logic "1" at -16mA.
The million dollar question is: What is the best way of converting the voltage-mode TTL logic to the current-mode NIM logic? And how can I best ensure that the signal is transferred with its fast leading edge intact? The NIM crate in question is a fast timetagger, and so propagation delay jitter in the logic level converter/line driver/coax cable is of importance and must be less than 1ns. The total propagation delay does not matter, only jitter does.
I look forward to your suggestions!