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MTD Readout Electronics

J. Schambach

University of Texas

Hefei, March 2011

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TOF Electronics Overview

The same as TOF, mostly…

• THUB, TCPU, TDIG are identical– Each TCPU reads out 3 or 5 TDIG (1 backleg)

• MINO is a 4-NINO version of TINO– Each MTD tray gets 1 MINO & 1 TDIG

• MTRG – this is a new card; it combines the NINO trigger outputs logically and sends a signal to trigger: the earliest east-end and west-end signal for each backleg

• MFTB – a new un-powered board that “closes” the gas box (tray) and passes the MRPC signals to MINO

• There are 2 THUB, 28 TCPU, 118 TDIG, 118 MINO, and 28 MTRG boards in the MTD electronics

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MTD Electronics Overview

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Feed-through board “MFTB”

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Front-End Electronics “TINO”TINO

NINO C

NINO B

NINO A(8 ch Amp / Disc)

MRPC 4(6 ch)

MRPC 1(6 ch)

MRPC 3(6 ch)

MRPC 2(6 ch)

Multiplicity to TDIG PLD(1 bit LVDS)

Hits to HPDTC(8 LVDS)

Threshold(All Common from TDIG)

MR

PC

Inte

rfac

eM

RP

C In

terf

ace

MR

PC

Inte

rfac

eM

RP

C In

terf

ace

6

6

6

6

6

6

2

4

4

2

8

8

TD

IG Interface

TD

IG Interface

TD

IG Interface

MINO (“MTD TINO”)

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CERN/LAA NINO Chipdeveloped for ALICE

Parameter Value

Peaking time 1ns

Signal Range 100fC – 2pC

Noise (with detector) < 5000 e- rms

Front edge time jitter <25ps rms

Power consumption 30 mW/ch

Discriminator threshold 10fC to 100fC

Differential Input impedance 40Ω< Zin < 75Ω

Output interface LVDS

MINO

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Digitizer Board “TDIG”

TDIG

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HPTDC: Data driven TDC• Only stores data when hit detected• Variable latency over full (1/4) dynamic range

Compromise between hit rate and latency• Triggered / non triggered mode• Multiple overlapping triggers• Channel merging possible via derandomizers

Limits hit rates• Good double pulse resolution

But complicated dead time analysis• Buffer occupancies must be seriously analyzed• Buffer overflows must be handled carefully

– Hit may be lost if marked– Complete events must never be lost

• Wide latency buffer (covers full dynamic range)• More complicated architecture/implementation

Previous data driven TDC worked well in different applications– Logic complication handled by logic synthesis– Extended verifications at behavioral/register/gate

level• High flexibility

Large dynamic range

FIFO orDual port RAM

Hit

Triggertime tag

Compare time

OutputFIFO

Trigger

-

Latency

Derandomizer FIFO’s

Common FIFO

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HPTDC Time Measurement

Coarse time(bin width 25 ns, 11 bits)

PLL bits(bin width 3.125 ns)

DLL bits(bin width 98 ps)

MSB LSB

R-C bits(bin width 24.4 ps)

HPTDC is fed by a 40 MHz clock giving us a basic 25 ns period (coarse count).

A PLL (Phase Locked Loop) device inside the chip does clock multiplication by a factor 8 (3 bits) to 320 MHz (3.125 ns period) .

A DLL (Delay Locked Loop) done by 32 cells fed by the PLL clock acts as a 5 bit hit register for each PLL clock (98 ps width LSB = 3.125 ns/32).

4 R-C delay lines divide each DLL bin in 4 parts (R-C interpolation)

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HPTDC Buffering & Readout

Level-0 Trigger

BunchCrossing Hit Buffer

Level-0Buffering

8 channel @ 25ps

or

32 channels @ 100ps

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Tray Controller “TCPU”

TCPU

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MTRG

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DAQ/Trigger Interface THUB

National’s SerDes Chip

ALICE DDL Link

J. Schambach 19

Front-end electronicsFront-end electronics

DetectorData Link

DDL SIUDDL SIU

DDL DIUDDL DIU

RORCRORC

SourceInterfaceUnit

DestinationInterfaceUnit

ReadOutReceiver Card

PCPCData

Acquisition PC

Optical Fibre~200 meters

PCI

THUB

DOE Review Aug 10/11 2009

J. Schambach 20

Electronics Monitoring & Configuration Tool

J. Schambach 21

Global System Clock Distribution

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HPTDC Readout Paths

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