Hardware
Description
ComTec GmbH
2-3
Stop inputs:
Two BNC connectors accept FAST NIM pulses (Stop signals) (input impedance = 50
Ω
) in TDC
mode. Is not used in PHA/SVA mode.
All FAST-NIM inputs have ECL differential receivers and input diodes as it is shown in Figure 2.3.
The diodes are used to prevent the inputs from positive and large negative pulses. The input
threshold of the receivers is fine tunable in a range of –1.0 V .. –0.1 V (referred to the input
signal) in steps of 1.22 mV.
2.2.2. MONITOR
outputs
Two BNC connectors.
-5V
-2V
GND
GND
-5V
50R
4
2
3
VBB
7
6
STOP In
GND
ECL STOP
TDC Threshold
Figure 2.3: FAST-NIM input schematic
Mode
Function
Output
Operation
PHA
SCA (Single Channel Analyzer) TTL out
SVA
Not used
TDC
TAC (Time proportional amplitude)
Adjustment
TDC Threshold
fast NIM threshold level
ADC Threshold
ADC threshold level
LLD
Lower level discriminator level
ULD
Upper level discriminator level
C/A SEL
Not used
Figure 2.4: MONITOR output signals
