N1568B
Obsolete
16Ch Programmable Pulse Shape Amplifier &Dual 16Ch CFD (30%; 80%)
Features
- 16 channels in a one unit wide NIM module
- Positive or negative inputs accepted on each channel
- ±4 V input dynamics
- Completely programmable via RS485 interface
- Programmable (2 bit) shaping time per channel
- 2bit coarse gain and 7 bit fine gain for energy amplifier
- 2bit coarse gain for timing amplifier
- 8 bit pole zero adjustment
- Programmable stretcher threshold
- 16 channel stretched energy output
- Dual 16 channel CFD (30% and 80% constant fraction)
- 16 channel 30% CFD multiplexed output
- Energy multiplexed output
- OR and Sum output
- Libraries, Demos (C and LabView) and Software tools for Windows and Linux
Overview
The Mod. N1568B is a 16 channel Pulse Shape Amplifier and Dual 16 Channel Constant Fraction Discriminator (30% and 80% constant fraction) implemented in a single-width NIM module. Each channel is composed by two sections: Energy section (A) and Timing section (B). The input signal is sent to both sections simultaneously. Section A processes the input signal with a differential circuit, followed by the gain stages (coarse: 2 bit; fine: 7 bit), by the shaping circuit and finally by a stretcher with programmable threshold (20 mV minimum).
The stretcher gate is generated by means of the threshold of the timing section and the output width of the stretcher signal is fixed at 15μs circa.
The 16 Channel Stretched Outputs are provided to the (OUT) connector present on the Front Panel; if the stretcher is disabled a Gaussian output is provided. The Stretched Outputs shall be fed to a QDC suitable to negative pulses; Gaussian outputs must be used with negative polarity in order to adjust Pole zero, shaping, etc. Discriminators Out does not work as the stretcher is disabled.
Section B processes the signal with a low noise differential stage (500 ns) followed by a 2 bit programmable linear gain stage; the signal is then fed to two low walk and high resolution Constant Fraction Discriminator sections (30% and 80% constant fraction respectively).
The discriminators share a 8 bit common threshold; the discriminators delay is adjustable via PCB jumpers (6 steps from 15 to 150 ns).
The RS485 interface allows to handle most functional parameters such as Shaping Time, Coarse and Fine Gain, Input Polarity, CFD and Stretcher Thresholds, Pole Zero Adjustment etc.
Technical Specifications
- INPUT
Positive or negative pulses, max. amplitude of ±4V, 50 Ω impedance
- E OUT
stretched unipolar signal with a dynamic range of 0 ÷ – 8V max (on 1MΩ ), 50 Ω output impedance
- 30% CFD OUT
ECL output
- 80% CFD OUT
ECL output
- MUX E
on LEMO connector, 0 ÷ – 8V max (on 1MΩ), 50 Ω impedance; high impedance when disabled.
On double row connector, 8V. max., 50 Ω impedance, high impedance when disabled
- MUX CFD 30%
– 4mA current output (-200 mV on 50 Ω)
- "Σ"
Sum of OUT CFD 30%; – 1mA current output per hit, 50mV on 50 Ω
- ?OR?
on LEMO connector, standard NIM output; -16mA current output
on double row connector, -16mA current output
- INTEGRAL NON LINEARITY
±0.05% in 90% of the full scale @ Gain=Max and 4 µs shaping time (± 0.25% typ. for any shaping time).
- EQUIVALENT INPUT NOISE
< 100 µV (Gain=max; 4 µs shaping time)
- INTERCHANNEL CROSSTALK
-45 dB (at Gain =1 and 4 V input signal)
- COARSE GAIN RANGE
2bit adjustable (1, 2, 4, 8)
- FINE GAIN RANGE
7bit adjustable, from 1 to 2
- SHAPING TIME
selectable time constant of 0.5 µs, 1 µs, 2 µs and 4 µs by 2 bits
- THRESOLD OF STRETCHER SIGNAL OUTPUT
20 ÷ 700 mV (8 bit resolution)
- DELAY VALUE of the CFD
selectable by SMD zero Ω resistance on PCB between 15 to 150ns (6 steps)
- CFD 30% Jitter
≤100 psec FWHM ( 1V, 10nsec input )
- CFD 30% Walk
±250 psec from 50mV to 1V (20ns rise time, 15ns delay)
Compare
Compare with Amplifiers (Spectroscopy).
Loading...