MSI-8(data sheet V2.0_04)

8 channel preamplifier+ shaper + timing filter amplifier

mesytec MSI-8 is a compact 8 channel preamplifier shaper box with integrated timing
filter amplifiers. Due to the modular setup, preamplifier and shaper module types can beselected individually for each channel. MSI-8 is the ideal solution for setups with a mix ofdifferent detectors requiring individual bias supply and energy ranges. It is also well suitedfor moderately segmented strip detectors or as an easy to use and flexible lab system.

Features:• Gain continuously adjustable by a factorof 50 (front adjustment factor 10,Jumper at preamp x5)• 8 channel compact standalone module• Preamplifier and shaper modules
individually selectable• Shaper with baseline restorer• Two shaping times, jumper selectable• Integrated timing filter amplifier• Individual and common timing output• Single and common detector bias
• All outputs can be terminated with 50 Ω
• Lemo connectors for in- and outputs• Discriminator gate output for peaksensing ADC
Schematics:

mesytec GmbH & Co. KG
Wernher-von-Braun-Str. 1, D-85640 Putzbrunn, Germany
phone: +49 - 89 / 456007-30 fax: +49 - 89 / 456007-39
info@mesytec.com - www.mesytec.com

MSI-8

8 channel pre-amplifier shaper box

System Design
MSI-8 has a very flexible modular design. Preamplifiers and shaper, timing filter amplifiers are pcb modules
mounted on a common main board. They can be chosen individually for each channel. This gives maximum
flexibility for multi channel setups with different detectors.

Rear Panel

Preamplifier inputs

Pulser input• Lemo connectors directly situated on thepreamplifier module• Tail pulse, or square pulse• Internally terminated with 50 Ω
• Typically 5 V for maximum output voltage
at minimum gain

Detector bias

• Lemo connectors directly situated on thepreamplifier module• Connect bias switches allow to select a channelgroup to be commonly biased. (Bias inputs ofthis group are connected). This allow easier cabling.

mesytec GmbH & Co. KG
Wernher-von-Braun-Str. 1, D-85640 Putzbrunn, Germany
phone: +49 - 89 / 456007-30 fax: +49 - 89 / 456007-39
info@mesytec.com - www.mesytec.com

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MSI-8

8 channel pre-amplifier shaper box

Front Panel

Shaper outputs

Power supply••••• SUB-D 9 female connector. (NIM convention)• Supply voltages(currents for box with 8 shapers and 8 preamps)

Lemo connector
Positive, Gaussian pulse
Max 10 V (8 V at 50 Ω)
Two jumper selectable shaping times(standard is 1 us FWHM and 2 us FWHM)• Gain adjustable by a factor of 10 via front
panel trim potentiometer.
Timing output+12 V
250 mA+6 V
50 mA–6 V–170 mA
total power: 4.3 W• Pin connections(numbers are noted on the connector):• Lemo connectors• Fast negative signal• Max –1 V

• scales with shaper gain setting

pinnamepinname

Common timing output

1Gnd

6

Not connected

2Gnd

7

Not connected

3+6 V

8

Not connected

4+12 V9

Not connected

5–6 V

is a sum of all individual timing outputs.
Differential preamp outputs• 20 pin standard connector• 8 differential preamp signals• Can be connected to a twisted pair cable andterminated with 100 Ω• Amplitude: ±1 V for maximum range
Gate output and gate threshold adjust• NIM signal output• Useful for gating an external peak sensing ADC
in lab tests. As long as one of the shaper outputs
exceeds the threshold voltage, the NIM-output
gets negative.

Box size

length = 170 mm
width = 105 mm
height = 67 mm

mesytec GmbH & Co. KG
Wernher-von-Braun-Str. 1, D-85640 Putzbrunn, Germany
phone: +49 - 89 / 456007-30 fax: +49 - 89 / 456007-39
info@mesytec.com - www.mesytec.com

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8 channel pre-amplifier shaper box

Preamp Module (MMPR-1)

Shaper Output
Input• The standard preamplifiers can handle a detector capacity of up to 1000 pF
Detector bias

• Maximum bias voltage: ±400 V• Bias filter 10 MΩ / 50 MΩ
(selectable by internal jumper)• Gain potentiometer factor of 10• Filtering: quasi Gaussian (CR(RC)5)• Shaping time (FWHM):
2 us: left jumper position
1 us: right jumper position

Attenuator switch by factor of 5

• Baseline shift with frequency:• A passive baseline restorer is integrated• For 1 us shaping time and a rate of 100 kHz,the baseline shifts less than 100 mV (1 %)• DC Offset at shaper output: U <10 mVPolarity

Pole zero adjust:Sensitivity

a double swich allows to select the input polarity. The two jumpers always have to be side byside. Left position negative input charge, rightposition positive input charge.

• Modules are adjusted to less than 20 mV of undershoot at the shaper output• You can readjust if necessary
Timing Output

Power consumption• Low power: typ 150 mW• cooling not necessary
For details see data sheet of MMPR-1Shaper Module (MMSH-1)
The module includes a shaper with passive baseline restorer, an output driver for 10 V (8 V @ 50Ω) and a timing filter stage with timing output.
The jumper allows to select one of the two
shaping times.

• Timing filter amplifier(is included on the shaper module)• integration: 7 ns
• differentiation: 200 ns• Noise:N = (70 + CDet) * 0.35
CDet = cable + detector capacity, in pF;
N = noise FWHM in keV;
Power consumption+12 V
10 mA–6 V
10 mA
total power = 180 mWConnector(left pin = 1)
pin

name

pin

name

1

gnd

6+12 V

2in+7gnd

3in–

8out shaper

mesytec GmbH & Co. KG
Wernher-von-Braun-Str. 1, D-85640 Putzbrunn, Germany
phone: +49 - 89 / 456007-30 fax: +49 - 89 / 456007-39
info@mesytec.com - www.mesytec.com

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MSI-8

8 channel pre-amplifier shaper box

4gnd

9out timing

5–6 V

10gnd

For details see data sheet MMSH-1

Timing considerations
Best timing• Use high bias voltage to get maximum charge
carrier velocity in the intrinsic zone of thedetectors• Implant particles with low range on the p-side(=strip side or guard ring side for 2 sideddetectors)!
Time resolution with external leading edge
discriminator• Use a low threshold to minimize walk
• If you have a wide range of input amplitudes,
use shaped signals for walk-correction• If the signal is much larger than the noise, thetiming resolution t can be estimated:

N = noise [MeV]
S= signal amplitude [MeV]With external constant fraction discriminator• fraction = 0.25, delay = 15 ns• timing is 25 % worse, but walk correction isintrinsic
Common timing output• For low energies (<10 MeV) about three times
worse than single channel timing (noise increased by √8)• For higher energies
Noise is not the limiting factor. If a coincidencewith responding energy channels is used insoftware, the 8 channels can be calibrated withindividual timing offset parameters.
If there is no coincidence, the timing information will not get better than 0.5 ns due to delay
tolerances for the 8 channels.

• For 100 pF detector + cable capacity and1 MeV signal this means a timing resolutionof t = 1 ns• Timing resolutions better than 100 ps are
difficult, even for large signals

mesytec GmbH & Co. KG
Wernher-von-Braun-Str. 1, D-85640 Putzbrunn, Germany
phone: +49 - 89 / 456007-30 fax: +49 - 89 / 456007-39
info@mesytec.com - www.mesytec.com

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