1. SALTRO16 activities in Lund
Lund University
presented by
Ulf Mjörnmark

2. EUDET/LCTPC setup in september 2010
Low voltage
Front End Electronics
Kapton cables
TPC
Magnet

3. ALTRO based Front End Electronics & DAQ
Hardware is based on ALICE TPC readout electronics

4. Summary of experiences with the ALTRO electronics
-Excellent noise, ca 350 electrons on a FEC connected to the chamber
-Operated reliable when taking data in test beams at DESY:
2009: February – March, July, September
2010: September, December
-In September 2010 the system operated with:
7680 channels (60 Front End cards)
3 RCUs, 2 DRORCs
Problems
-Breaking amplifier channels
-Needs compressed air cooling . Not a practical solution for the future

5. Broken channels due to discharges in the GEM system?
Happens too frequently , may in the worst case kill a FEC i.e 128ch.
Has to be solved.
Have emulated with injection of 1mJ in amplifier input.
Kills the internal protection of the channel with same symptoms as real failure.
External diode network as below works as protection for emulated input.
Survives injection of 20mJ.
Will be tested for noise .
Testing on GEM chamber at next DESY test (june 2011).
Evaluate. Final placement?

6. New design
Backplane
Front End Card
Pad plane
SALTRO16
MCM
Multi Chip Module
16 ch ALTRO
PCA16
Kapton cable
PAD plane

7. PADPANEL WITH SALTRO CHIPS ON IT - ANDERS

8. trace routing from pads to SALTRO16 becomes simpler
Advantages of Multi Chip Module (MCM) compared to all electronics on the padpanel:
trace routing from pads to SALTRO16 becomes simpler
- MCM module offers 2 extra layers for components.
electronics prototyping will be cheaper and easier.
parallell prototyping possible
possibility to distribute design and fabrication
-analog and digital functions are well separated,
- minimal heat transport to the TPCendplate
service by replacement of MCM module.
simpler endplate construction
SALTRO16 mounted on padpanel imply 1x9mm pads

9. Horisontal FEC-MCM design
Back plane
LV Voltage
regulators
FPGA Board CTRL
LV&ctrl
FEC-MCM
Padpanel

10. Horisontal design Top side FEC-MCM 8 SALTRO16 128 channels
Naked Si wirebonded to board
Card size 31.5*23.5mm
Pad pitch 1x5.9 mm possible
Connectors to
LV&CTRL board
4 connectors
to pad board
Below side

11. On a pad panel. 6*6 matrix of FEC-MCM. Total 4608 channels,
pad size, 1.0*5.9mm possible
On a pad panel.
234 mm
170 mm
Connector
FEC-MCM
209 mm

12. But in the prototype stage where we are now and a couple of years to come
we think that an FEC-MCM module with 128channels is too risky and expensive
-Risky as long as the broken channel problem is not under control
-Even if we understand this problem, this electronics will be used in tests of
various avalanche chamber prototypes. This is a danger in itself.
Expensive to replace 128 channels if one is broken.
Expensive to manufacture since the chip yield is unknown and the chance of
assembling 8 working but untested chips on a board may be quite low.
The SALTRO16 is a rather large chip. The yield can be as low as s 90% (including
bonding). Then only 43% of the modules will be OK if there are 8SALTRO per
module
As a consequence we think that most prototyping has to be made with a
smaller MCM module.

13. VERTICAL 32chMCM with 2 SALTRO
Pad pitch 1x4.6 possible
Bus card
LV&CTRL
32chMCM
SALTRO16
SALTRO16
PAD PLANE

14. SALTRO16:
Evaluation at CERN:
64chMCM:
Specification :
Design:
Test:
Redesign and fabrication:
Test:
LV&CTRL/Buscard:
Design:
Fabrication:
Test with ALTRO+PCA16:
Redesign and fabrication:
Test:
Small System test:
64chMSM/LV&CTRL/Buscard:
Final fabrication:
Full System test:
Input protection:
Beam test at DESY:
Evaluation:
PCMAG:
to Japan:
back: