1HEP2005, Lisboa 21-27 July 05 Roberto Campagnolo - CERN

HEP2005 International Europhysics Conference on High Energy PhysicsHEP2005 International Europhysics Conference on High Energy Physics

( Lisboa-Portugal, 21-27 July 2005 )( Lisboa-Portugal, 21-27 July 2005 )

Readout Electronics for the ALICE Time Projection ChamberReadout Electronics for the ALICE Time Projection Chamber

Roberto Campagnolo – CERN PH-ED

Outline:Outline:

• The ALICE TPC FEE Design Requirements

• Overview of the main Components

• Measurements

• Conclusions

2HEP2005, Lisboa 21-27 July 05 Roberto Campagnolo - CERN

510 cm

EE

88μs

400 V / cm

The ALICE Time Projection Chamber layout

GAS VOLUME: 88 m3

90% Ne - 10%CO2

114556 cm

LARGE DATA VOLUME :

• 570 132 (pads) x 1000 (time bins)

• 712 Mbytes / event

• Pb – Pb (@200 Hz) 142 Gbyte / s

• p-p (@1KHz) 712 GByte / s

READOUT PLANE SEGMENTATION :

18 trapezoidal sectors per side

each covering 20 degrees in azimuth

3HEP2005, Lisboa 21-27 July 05 Roberto Campagnolo - CERN

ALICE TPC FEE – Design Requirements

No. of channels : 570 132 ( 1 MIP = 4.8fC , S/N = 30:1 , Dynamic = 30 MIP )

Dynamic range : 10 bits

Sampling rate (shaping time ~ 190ns) : 10 MHz No. samples / channel (drift time ~88 µs): 1000

Zero suppr. data (<occ.> = 15%) : 108 MByte / event L1 (start digitization) rate: ~ 200 Hz

Tail cancellation within 1 s (minimize pile-up) : ~ 1‰

Power consumption (detector ΔT =± 0.1 ºC ) : < 100 mW / channel

Tolerance to Radiation Single Event Effects

4HEP2005, Lisboa 21-27 July 05 Roberto Campagnolo - CERN

ALICE TPC Readout organization and components

Inner chamberInner chamber

Outer chamberOuter chamber

FEC

P1 : 18 FECs

P6 : 20 FECs

P4 : 20 FECs

P3 : 18 FECs

P2 : 25 FECs

P5 : 20 FECs

36 Sectors, 6 Partition each

5HEP2005, Lisboa 21-27 July 05 Roberto Campagnolo - CERN

ALICE TPC Readout organization and components

36 Sectors, 6 Partition each

Example of Partition equipped withFECs, Readout Backplane and RCU

RCU

Ethernet( 1 MB/s )

Detector Data Link( 200 MB / s )

COUNTING ROOM

ALTRO bus (2 x 200 MB/s)

Local Slow-Control (2 x 2Mb/s)

ON DETECTOR

1

13

2

14

12

Up-to 25

DCS int.

SIU int.(DDL-SIU)

Trigger int.(TTC-RX)

PASA – ADC – DIG.

DE

TE

CT

OR

TTC optical Link(Clock, L1 and L2 )

ALTROBus

Interface

Dataassembler

Data Acquisition RORC

Detector Control System

Timing, Trigger and Control

Partition Architecture :128 ch-FEC

128 ch-FEC

128 ch-FEC

128 ch-FEC

128 ch-FEC

128 ch-FEC

Slow Control

Interface

Inner chamberInner chamber

Outer chamberOuter chamber

FEC

P1 : 18 FECs

P6 : 20 FECs

P4 : 20 FECs

P3 : 18 FECs

P2 : 25 FECs

P5 : 20 FECs

6HEP2005, Lisboa 21-27 July 05 Roberto Campagnolo - CERN

The ALICE TPC Front End Card (4356 units in total)

17 cm

19 c

m

Pre-AmpliShaper

10Ms/s10bitADC

DigitalCircuit

8 PASA CHIPS( 16 CH / CHIP )

8 ALTRO CHIPS( 16 CH / CHIP )

128

Ch

ann

els

anode wire

Pa

d p

lan

e

drift region88s

DETECTORDETECTOR

570132 PADS

gat

ing

gri

d

Multieventbuffer

Baseline correction, Tail Cancellation,

Zero supression

GT

L b

us

-tra

ns

ce

ive

rs

Board SupplyAnd

Monitoring

Board

Controller

(FPGA)

CUSTOM IC

(CMOS 0.35m)

CUSTOM IC

(CMOS 0.25

m )

7HEP2005, Lisboa 21-27 July 05 Roberto Campagnolo - CERN

The Pre Amplifier – Shaper Amplifier

AMS 0.35 m – Die area : 18 mm2

Gain : 12mV / fC

FWHM : 190ns

Noise : 566e ( @ 12pF )

INL : < 0.3 %

Crosstalk : ≤ 0.1 %

Power : 11 mW / channel

Produced 49350 chips, Yield 83%

CfRf

(RC)4

+-

Q/Cf

Q

OPA OPA OPA

Cf//Rf

CSA SHA OA

16 CH – PASA MAIN CHARACTERISTICS

PASA RESPONSE FUNCTION

FWHM = 190 ns

Q = 149 fC

A(t / )4e-4(t/)

[ns]IN

OUT

[ADC]

8HEP2005, Lisboa 21-27 July 05 Roberto Campagnolo - CERN

The ALiceTpcReadOut chip

010011010001011101010011010001011110010011010001011010

01001101000110111010110011000111001010011010 010011010001101110010 010011010001101110010 010011010001101110010

BaselineCorrection

I

+

–

TailCancellation

BaselineCorrection

II

ZeroSuppression

010011010001101110010010011010001101110010010011010001101110010

DataFormat

Memory+

Multi-EventBuffer

010011010001011101010011010001011110010011010001011010

01001101000110111010110011000111001010011010 010011010001101110010 010011010001101110010 010011010001101110010

BaselineCorrection

I

+

–

TailCancellation

BaselineCorrection

II

ZeroSuppression

010011010001101110010010011010001101110010010011010001101110010

DataFormat

Memory+

Multi-EventBuffer

MAX SAMPLING CLOCK 25 MHz MAX READOUT CLOCK 60 MHz

Process: ST 0.25 µm HCMOS7 ( 6M transistor )

Online baseline correction / tail cancellation

800 k-bits internal memory

Single Event Upset-proof redundant control

area: 64 mm2

power: 16 mW / ch

Resolution: 9.7 ENOB

Readout BW: 300 MB/s

49 000 pieces produced - Yield 84 %

16-CH Signal Digitizer and Processor

9HEP2005, Lisboa 21-27 July 05 Roberto Campagnolo - CERN

ALICE TPC Readout Control Unit (216 units in total)

23 cm

SIU

DCS Interface

Ethernet

Detector Data Link

TTC optical Link

(Data Acquisition)

(Detector Control System)

(Timing, Trigger and Control )

13.5

cm

( 200 MB / s )

( 1 MB / s )

RCU Functions: Readout related: Slow Control related:

• Configuration of the ALTROs Supervision and monitoring :

(via the DDL or the DCS) - Configure the power state of the FECs

• Distribution of the trigger and clock signals - Temperature, Current and Voltage variations

(from the TTCrx) - Read status parameters (L1 and L2 counters…)

• FEC data readout and transfer to the DAQ - Interrupt and error handling

via the DDL

by the ALTRO bus (VME-like custom bus) by the Local Slow Control bus (I2C-like custom bus)

10HEP2005, Lisboa 21-27 July 05 Roberto Campagnolo - CERN

ALICE TPC Readout Electronics - Measurements

Average Noise:~ 0.68 ADC counts (r.m.s.) ≈ 730 e- [TDR: <1000e-]

Time bin

AD

C C

ount

s System Noise

Tail Cancellation Filter and Moving Average Filter effects

High Multiplicity Event in Field Cage Prototype( 5500 FEE channels )

Typical Pulse shape

11HEP2005, Lisboa 21-27 July 05 Roberto Campagnolo - CERN

The ALICE TPC is readout with an innovative electronics with on-detector digital signal processing.

Test performed on a sizeable fraction of the final electronics show that the system fulfills all requirements, in particular:

- Power consumption : 40mW/ch

- System Noise ~ 730 e-

- Baseline restoration at 1 ‰ of the Dynamic Range within 1 μs

Production and test of components is on schedule for the start installation in Fall 2005 and detector commissioning in Spring 2006

Conclusions

12HEP2005, Lisboa 21-27 July 05 Roberto Campagnolo - CERN

End of presentation

13HEP2005, Lisboa 21-27 July 05 Roberto Campagnolo - CERN

Digital Conditioning of the TPC signal

INPUT SIGNAL AFTER 1st BASELINE CORRECTION

AFTER TAIL CANCELLATION AFTER 2nd BASELINE CORRECTION

14HEP2005, Lisboa 21-27 July 05 Roberto Campagnolo - CERN

Single Event Functional Interrupts with Xilinx Virtex-II Pro FPGA

( Reconfiguration started after 200 seconds, errors are then continuously detected and corrected )

• Test conditions– Flux = 3.7 x 1011 protons/cm2/s– Reconfiguration time = 5 s

• Real life– Flux = 7.9 x 102 hadrons/cm2/s– Reconfiguration time = 10 ms

• Duty cycle: 1011 times better in real life

Readout Control Unit – Xilinx FPGA radiation tests

15HEP2005, Lisboa 21-27 July 05 Roberto Campagnolo - CERN

Integration with the DetectorConfiguration for the Test-Beam (May 2004) and Cosmic Rays (2005)

IROC in Field Cage prototype readout with:

43 FECs ( 5500 channels , ~1 % of Alice TPC ) connected to2 RCUs by4 branches of ALTRO readout backplanes.2 DCS boards interfaced to the RCUs and connected to the TTC, 2 SIUs for the DDL‘Realistic’ Power supply distribution: Wiener500 with 40 m. cables