V812
16 Channel Constant Fraction Discriminator
Features
- Thresholds individually programmable via VME
- Constant fraction for precise discrimination timing
- ECL outputs with fan-out of two
- Programmable output width
- Global VETO and TEST inputs
- Mask register for individual channel enable/disable
- OR, CURRENT SUM and MAJORITY outputs
- Libraries (C and LabView) and Software tools for Windows and Linux
Overview
The CAEN Mod. V812 is a 1-unit wide VME module housing a 16 channel constant fraction discriminator. The module accepts 16 negative inputs and generates precise ECL pulses when the input signals exceeds a given threshold: constant fraction technique allows to precisely determine the timing of the discrimination. The pulse forming stage of the discriminator produces an output pulse whose width is adjustable in a range from 12 ns to 206 ns (typical values) via VME.
Moreover, in order to protect against multiple pulsing, it is possible to program via VME a dead time, from 118 ns to 1625 µs (typical values) , during which the discriminator is inhibited from retriggering. The discriminator thresholds are individually settable via VME in a range from -1 mV to -255 mV (1 mV step) through an 8-bit DAC. Each channel can be turned on or off via VME by using a mask register. A Current Sum output generates a current proportional to the input multiplicity, i. e. to the number of channels over threshold, at a rate of -1.0 mA per hit (-50 mV per hit into a 50 Ω load). The module can operate also with small (below 10 mV) input signals. A MAJORITY output provides a NIM signal if the number of input channels over threshold exceeds the MAJORITY programmed value. Several V812 boards can be connected in a daisy chain via the Current Sum output: in this case, by switching the majority logic to External, it is possible to obtain a Majority signal when the number of active channels in the chained modules exceeds a global Majority level. The logic OR of discriminator outputs is available on a front panel NIM signal.
Technical Specifications
- Packaging
6U-high, 1U-wide VME unit
- Inputs
16 inputs (negative polarity, 50 Ω impedance)
- Max input voltage
-5 V
- Min detectable signal
-5 mV
- Threshold range
-1 mV to -255 mV (1 mV step)
- Constant fraction
20%
- Delay
20ns full scale with 4 ns steps (8 ÷ 20 ns operating range)
Optional:- 5ns full scale with 1ns steps (4 ÷ 5 ns operating range)
- 50ns full scale with 10ns steps (10 ÷ 50 ns operating range)
- 100ns full scale with 20ns steps (20 ÷ 100 ns operating range)
- Outputs
16 ECL outputs with a fan-out of two
- Input/output delay
Set delay + 4.5 ns ± 2 ns
- Output width
Programmable from 12 ns to 206 ns (typical value)
- Dead Time
Programmable from 118 ns to 1625 ns (typical value)
- Max outputs time walk
±400 ps for input signals in the range from -50 mV to – 5 V with 25 ns rise time
- Autowalk
Automatic adjustment of input offset and low frequency input noise of ±40 mV
- Control inputs
NIM logic signals, high impedance: VETO: allows to veto all channels simultaneously TEST: triggers all the enabled channels at once
- Control outputs
- VETO IN: NIM signal, high impedance, allows vetoing of all channels simultaneously
- TEST IN: triggers all the enabled channels at once
- OR OUT: standard NIM signal, 50 Ohm impedance, logic OR of outputs;
- SUM OUT: current proportional to input multiplicity (-1 mA ±20% per hit), high impedance
Compare
Compare with Discriminators.
Loading...
Ordering Options
Code | Description |
---|---|
WPERS0081201 | V812 Customization - Delay 100ns RoHS |
WPERS0081202 | V812 Customization - MSU Delay 5ns RoHS |
WPERS0081203 | V812 Customization - Delay 50ns RoHS |
WV812XBAAAAA | V812B - 16 Channel Constant Frac. Discriminator (No JAUX) RoHS |