MMR Multichannel Readout

32 to many 1000 channels
detector readout system(Data sheet V1.0)

MMR Multiplexed Readout is a platform for multiplexed readout of large arrays of silicon detectors MWPCs or other charge generating particle detectors. It consist of a masterboard, which performs time multiplexing, analogue to digital conversion, data storage andtriggered data transmission via optical link to a central data collector module. The board
provides a local clock, which is synchronised by the VME master to a central time.
Timestamp resolution is 1ns (starting from 2021).
Hardware features:• Modular Setup• miniaturised detector front ends optical Link
• Up to 128 channels per front end• Large data buffer on front end• Amplifier, filter and digitization on front end• Self triggering• Possible ranges:◦ 500 keV to some GeV (1 GeV = 45 pC)◦ Noise < 3 keV FWHM for 0 pF input cap.
• Front end synchronisation to a central clock• time stamping in front end, 1nsresolution• absolute time stamping allows to buffer thedata at the front end without loss of timing
information• Easy to handle Optical POF fiber bus• Only standard lab tools required to assemble
the fibers• Inexpensive twin fibers available• Fast 200 Mbit front end bus• Up to 50 m with POF fibers• Works with a single +6.0 V to +8.0 V supply

Stacked boards for 128 channels
60 x140 x20mm3

Easy galvanic separation of front end

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

MMR Multichannel Readout32 to many 1000 channels
detector readout system

Overview: MMR – Systemmesytec 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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MMR Multichannel Readout

32 to many 1000 channels
detector readout system

MMR Detector Front end module
Analogue part:••••

Bias supply, pulser coupling
low noise charge integrating pre-amplifier
shaper stretcher stage
timing filter with discriminator

32 channels
each layer
ShaperIntegratorStretcher

TF-Integrator

Discriminator

Differentiation,
Pole Zerobias
pulser

Detector AC Coupling
BiasPulser

ChargePreampAmplitude

TriggerThresholdAt the input, the signals are AC coupled and biased via resistor to a defined detector voltage up to 250 V orground. This eliminates effects of high detector leakage currents on the charge sensitive preamplifier,and allows to bias, for example Si strip detectors or Si PMTs.
A pulser coupling allows do apply a pulser and provides a full check of electronics from input to dataacquisition. The charge sensitive preamplifier can be configured in a wide sensitivity range and delivers a tailpulse with up to 10 ns rises time. It has a high open loop gain and allows to integrate input load capacities ofup to 1 nF.
The following differentiation stage also includes the PZ compensation and works as part of the shaping filter.
The signals are now split to an amplitude path starting with a second order integrator and a stretcher. Afterthe stretcher, a static amplitude is available for further multiplexing.
The timing path starts with a fast integrator followed by a discriminator. All discriminator signals of one
bank are "Ored" and sent to the digitization.

Digital part:••••••

Digitisation: MMR-128 in 1.4 us,MMR-64 in 0.7 us.
Synchronised clock
Time stamping
Zero suppression
Buffering
Generates pulser 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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MMR Multichannel Readout

32 to many 1000 channels
detector readout system

To / From Analog Frontends

max 4 x 50 MHz
12 bit ADCs
ADC
128Channels

ADC

MUX

ADC
ADC

Opt.
Transceiver

FPGAtime stamping
zero suppression● buffering

Optical Link●●ClockRegeneration

4 Triggers
Pulser4 Threshold
DACs

DCDC
Converters

power+6 to +8V

Up to 128 amplitudes are multiplexed to 4 ADCs running with 50 MHz. This allows to convert 128 channels
in 640 ns. The four input triggers from four banks start the readout and multiplexing sequence. The triggers
are ored, and get a time stamp with a precision of 5 ns / 300 ps / 30 ps
depending on firmware and detector requirements.
The trigger with time stamp is immediately sent via optical bus to the data collector module.
Converted amplitude pass a threshold filter to suppress non responding channels and reduce data.
The remaining channels are grouped to an event data structure and stored in a buffer.
The dead time is about the sum of shaping time + conversion time.
The event data are stored in the buffer until they are requested by the central data collector or a skip command is sent.
A fast 200 Mbit optical link, which is realised with optical POF (Plastic optical fibers) twin fibers transfers
triggers, data and front end configuration data.

Input (detector) side of an MMR 128 channel pack.
2 x high density 68 pin connector with 1.27 mm
pitch. Each connector 4 x ground + 64 channels.

Example:Detector board with 3 x MMR-128
for MWPC readout.

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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MMR Multichannel Readout

32 to many 1000 channelsdetector readout system

VMMR, the VME receiver module
The VME receiver module VMMR-8 / VMMR-16 has 8 or 16 optical buses.
With 16 buses, 8 of them are back on the motherboard.
The module synchronises the front end clocks, receives triggers on the buses
and accepts external gates.
••

Live insertion (can be inserted in a running crate)
Power consumption: 6.5 W+ 5 V, 1.2 A- 12 V, 50 mA.

MMR MMR MMR
Trigger path:● receive trigger,● send data request orskip

Data path

Ext trig. inTrigger
Triggerhandling:
handling:● find synchronous triggers● find synchronous triggers
Trig out ●● request or skip frontend event
request or skip frontend event
MMR to trigger out:
750 nsData
Databuffer
buffer

VME-busExternal trigger can be used to:● Get chopper time stamp● Synchronise events over several VMMR modules

Detailed functional description:
The VMMR data collector module receives triggers from up to 16 MMR detector front ends. A trigger handling unit allows to define a trigger, groups of triggers and two external trigger input as source for an event
generation. When an event is detected, the trigger time stamps are searched within a specified time (backward and forward in time) for coincident triggers. For coincident triggers the data from front end are requested, for non coincident a skip command is sent to the front end. All data which are now sent are formatted
into an event structure and sent to a large buffer.
They are now ready for readout by the VME-bus.
The data structure format is 1) a header 2) a time stamp for each front end with valid data, amplitudes withchannel address (front end address + channel address) for each responding channel. The end is marked by
EOE marker including a global event data time stamp.
The data format is compatible to all other mesytec digitizer modules.

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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32 to many 1000 channels
detector readout system

MMR Multichannel Readout

Optical Bus

Used in industrial networks, car networks, consumer electronics.
1 mm diameter multi-mode fiber with step refraction index.
Wave length 650 nm (red) -> inexpensive LEDs for transmitters.
Facts:Core 980 um: PMMA (acrylic) refractive index 1.49
Cladding: 10 um silicone resin (refractive index 1.46)
Jacket 2.2 mm diameter.
Damping 0.2 dB/m (after 50m: 10% of light )Up to 50 m of length with 200 Mbit/s (limited by dispersion)
Robustness under bending and stretching.
Low power and compact Transceivers available
Easy to handle
Inexpensive (twin fiber: 2 Euro/m)

JacketCladdingCoremesytec 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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MMR Multichannel Readout

32 to many 1000 channels
detector readout system

Possible front end configurations (by population of the boards)
Gain: Full range: 50 fC to 100 pC• Polarity:
pos / neg
• Shaping time:
150 ns to 5 us
• TF-time:
20 ns … 1 us
• Channels
32 to 128 per front end package• Mix of polarity and sensitivity on one front end module is possibleRealised Configurations:
TypePolarity

Sensitivity

TF time

Shaping time

Si Strip detector,
Beta detection

positive and negative

50 fC full range

200 ns

1.5 us

H8500-PMT +Scintillator readout

negative

100 pC

20 ns

100 ns

H8500-PMT +Scintillator readout

negative

10 pC

20 ns

250 ns

MWPC-readout

negative / positive

1 pC

200 ns

0.5 usScatterer:• Energy in silicon typ. 140 keV (6.4 fC)• Self triggering, threshold 15 keV• MMR energy range 600 keV• Noise 3 keV @ 0 pF (6 keV with detector)• Readout: 24 x MMR-64 = 1536 Channels• 24 optical buses → 2 x VMMR-16

Scatterer:
6 x 128 x 128 Silicon
Strip DetectorsTargetpAbsorber:• 8 x 8 multi anode PMT (H8500)• Readout: MMR-64

Position sensitive Absorber
Scintillator + PMT

Readout of Silicon Strip Detectors and PMTs in coincidence:

1 MHz Gamma rate from Target:• Scatterer: 15 kHz• Absorber: 150 kHz• Coincidences 15 kHz

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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MMR Multichannel Readout

32 to many 1000 channels
detector readout system

Data for this most sensitive configuration:
Measurements with pulser at a 32 channel board,configured for• 600 keV maximum range• 4k ADC conversion• Shaping time 1.5 us• TF-time 0.2 usLinearity:
The linearity is good, the channels are very homogeneous.
Pulse r Amplitude v s Output Amplitude
3000

Output [channels]

2500
2000

1500
1000
500
001000

2000

3000

4000

5000

6000

Pulser Input a.u.

Noise:
Input Capacity vs Noise
7

Noise [keV] FWHM

6543210020

406080100

Input Capcity [pF]

Noise at 0 pF = 350 ENC

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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MMR Multichannel Readout

32 to many 1000 channels
detector readout system

Readout: LYSO 10 x 10 Scintillator with H8500 PMT
H8500 readout, 64 channels (8 x 8 Anodes)(also Si PMTs are equally suited)•TF-time 20 ns, Shaping time 100 ns•

Polarity: negative•

dead time: → 700 ns•

Peak rate per 64 channel Front end:
0.4 MHz @ 75 % live time•

4 x 4 system, average rate 6.5 MHz•

Sensitivity 100 pC maximum

For test:• LYSO 10 x 10 crystals• pitch 4 x 4 mm
• 22 Na Source, (511 keV Gammas)

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

9/13MMR Multichannel Readout

32 to many 1000 channels
detector readout system

How to connect fibers,* How the optical bus is connected:
Connect the Fibers to VMMR module. Make a power cycle to let all optical transceivers get active.
At the other end of the fiber pairs you can now see light at one fiber.

Open the locker at MMR transceiver

MMR modulee with opened and closed locker
The fiber with red light has to be at the marked input (input arrow).
Insert the fiber pair into the transceiver (23 mm !!) until it hast contact to the internal optical units.
Some times with new cables it clamps somewhere inside with its jacket. So check carefully if it canbe inserted 23mm.
Close the locker to fix the fiber.
When the link is established, the red LED on the VMMR-bus should go off.

cutting, polishing of fibers

Handling of thresholds,* Why there are two thresholds ?
If any channel of one MMR gets an amplitude above the trigger threshold, all channels are converted.
Then the data threshold can be used to cut off noise (zeros) to reduce the amount of transmitted data.
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

10/13MMR Multichannel Readout

32 to many 1000 channels
detector readout system* How to adjust the thresholds.
Usually adjust the threshold up until there are very few triggers.
* The triggers can be seen at the green LEDs of the VMMR buses.
If the trigger rate has to be higher than can be checked by LED:* set the trigger output to one bus and check with oscilloscope* or check the rate of buses in the data acquisition.
For applications which require lowest threshold, some kHz of rate could be acceptable when a coincidence with thewindow of interest, triggered by an external low rate detector, can be established, or a very fast data acquisition allows
readout of the large amount of data.

Power Supply
MMR works from a single power supply of 6V to 8V
MMR-64 typical 400 to 500mA, MMR-128 typical 900mA
The crimp contacts are TE 927995-1 the crimp tool TE 726824-1
The connector shell: TE 928205-3

mesytec GmbH & Co. KGWernher-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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MMR Multichannel Readout

32 to many 1000 channels
detector readout system

Dimensions, MMR-64

Close view: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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MMR Multichannel Readout

32 to many 1000 channels
detector readout systemSignal path, ground connection

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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