Input stage clipping diode causing deterioration of pulse edges
The BAR66 diode in the input stage was causing severe degradation of the falling edge of the signal (with Tf > 300 ns) when the input was clamped due to too high amplitude of the pulses. This combined with analog noise in the trigger resulted in spurious events in the TDC FIFO.
Fix: replace the diode with a fast Schottky RF diode. Tested with HSMS-2802-TR1G.
To be included in EDA-02267-V4-1.