1. VeLo Analog Line Status
LHCb week February 2004
A. Bay, J. Borel, L. Locatelli, R. Frei
long line tests with beetle 1.3
the repeater board & cabling

2. Tests with Beetle 1.3 pre-compensation A B 3 pF 22k 60 m CAT6 Beetle50
repeater
oscilloscope
> 1 GHz
post-compensation C
clock
ADC
RB3
motherboard
8 bit
analog-board

3. Pre/post compensations
B1.3 A B C
ADC
pre post

4. Beetle 1.3
Q injected
4 links mode
26 unbonded
Header
6 bonded

5. A few FFTs
pre-compensation only
60 m cable
100 MHz
"Common Noise"

6. Some other FFTs A B C A, B on C off A,B off C on pre-compensation only
ADC
A, B on
C off
A,B off
C on
pre-compensation only
post-compensation only

7. 22k 50
3 pF
Calibration
1 MIP is 200 micrometers Si <de/dx> (not the "most probable")
i.e. 22kelectrons
To convert to most-probable: multiply by ~0.7
Example: calibration with RB3

8. Studies with oscilloscope
1) records ~300 events (sequences with samples ~0.1 ns resolution)
with and without charge injection
2) pedestal calculation
3) get an average pulse shape, choice of "sampling time"
4) analysis:
sample at sample points (0.5 ns width)
pedestal subtraction,
common noise correction,...
25 ns
channels
sample here ... and here ... and here

9. S/N & Residual vs phase scan
residual = A(t+25ns)/A(t) 40
S/N 30 20
residual % 10
-10 ns
scan
±8 ns

10. Oscilloscope .2 Calibration 0 1 MIP noise from unbonded channels CN
rms=0.05
rms=0.03 CN
correction
No CN
correction

11. Tests with RB3 A B C A=C= off B=470 pF A=on C=off B=120 pF B1.3 ADC
S/N = 31.2
Residual < 1 %
A=on C=off
B=120 pF
S/N = 32.7
Residual ~ 6 %

12. Tests with RB3 .2 "CN" from pipeline non-homogeneities ?
without CN subtraction
RMS=1.927 ADC
RB3 firmware modified
to register the pipeline
column number...
with
RMS=1.055 ADC
intrinsic system noise
(resistor instead of Beetle)

13. FIR studies Ai undercompensated signal Bi
Bi= 1.92Ai Ai Ai-2

14. FIR studies .2
001100
001010

15. FIR studies .3
001101
001110

16. Test beam configuration #1
pre-compensation
A B
repeater
60 m
CAT6
sensor
Beetle
1.3
ADC
AD bits
AD813x
VME
NA60 DAQ
resid. < 5%
S/N>20
RB3

17. Test beam configuration #2
pre-compensation
A B
repeater
60 m
CAT6
sensor
Beetle
1.3
ADC
AD bits
AD813x
VME
NA60 DAQ
push gain
and/or
reduce load resistor
value from
50  ~10 ohm

18. Repeater Board & Cabling

19. Repeater Board V2 OR Logic card (who is responsible ?) LV card :Vreg
HV connector : .?.
Service connector:
ntcA,ntcB,…?
8x driver board ver2
LV card :Vreg
(can be bypassed ?)
Logic card
(who is responsible ?)
LV connector
4x HD Dsub 44pins OR
16 RJ45
Front panel

20. Analogue link partitioning
V2.1
HD Dsub 44pins
4 bundles
88 boards
(5/crate max)
4 CAT6 / bundle
4 bundles/board
4x88=352 bundles
V2.2
16 RJ45
4 bundles

21. Power supply for Repeater Board
Approximate
Voltage before
regulators
1 repeater board
Cable: 24 twisted pairs + shield
Drivers
8 boards
(x8channels)
+7, -7 V (1A)
6 pairs in // plus 2 pairs sense-line
+4.5 V (6A)
1 Hybrid
16 Beetles
12 pairs + 1 sense
~15 [W] dissip.
in the cable
Logic
TTCrx,...
2 pairs + 1 sense
+7 V (1A)
5/crate max
24 crates (not all full equipped)

22. Crate for Repeater Boards
130 [W] dissipation/crate
No extra cooling system needed
20 RepBoards
6x4x4 crates
1 RepBoard
1 RepBoard VETO
partitioning to be reviewed

23. Layout Low voltage configuration : Caen ? Wiener ? NF48P cable 70m
LV cable bundle 4m
NF48P cable
70m
Connection
pannel
RPT board version 2
Dsub LV connector fem
Connection
pannel