We're using some fast (150 kHz) piezo pressure sensors mounted in line along a tube to measure the velocity of a pressure wave. The amplifier for these sensors has fixed gain and the output only jumps from 0 to 5 millivolts when the pressure wave passes. The timer-counters we're using require TTL-level inputs. I need to build an analog circuit that can trigger off the 5mV signal and deliver a high TTL output, somewhere between 2.7 and 5V. What would be a decent approach here?