Conventional cable specifications
Requirements
Design
Requirements
carry HV, power, sensing and control levels from PP2 to power supplies
Modularity:
basic modularity given by the SCT power distribution philosophy
each conventional cable connects to one power low mass tape at PP2
each line of power supply consists of 2 conventional cables
- PP2 to PP3: conventional cable with 1mm2 conductors for power lines
and 0.14mm2 for all other lines
- PP3 to power supply: conventional cable with 4mm2 conductors for power
lines and 0.25-0.3mm2 for all other lines
Length:
based on Technical Design Report, PP2 in-between LAr electronic boxes
PP2 to PP3: approx. 20m
PP3 to power supply: approx. 130m
High Voltage
according to SCT Bias Voltage Power Specification V2.03
- V_max = 500 V (HV component rating)
- I_max = 5 mA
Low Voltage
according to ATLAS SCT Low Voltage Power Specification V2.0
Conductor cross sections are chosen to limit the
voltage drop between power supply and PP2
(determined by power supply maximum output voltage of 8.5V and maximum voltage
at PP2
given by DMILL process limit of 5.5V)
analog (ABCD bipolar FE):
- I_cc_max = 1.3 A (prel.)
- V_cc_nominal = 3.5 V
digital (ABCD + opto CMOS)
- I_dd_max = 1.0 A (prel.)
- V_dd_nominal = 4 V
PIN bias
- V_max = 10 V
- I_max = 2 mA
VECSEL drivers
- V_max = 6.6 V
- I_max = 10 mA
Sensing and control
Sensing
- temperature on module (2 on barrel)
- V_cc, V_dd and respective returns at module connector
Control
SELECT for clock (opto redundancy scheme)
- V_nominal = 4.0 V
- I_max = 1 mA
RESET module
- V_nominal = 4.0 V
- I_max = 1 mA
all lines but RESET carry DC levels
Additional requirements
- minimize V drop between power supply and PP2
- reduced power dissipation
- flexibility in routing
- commercial production and assembly
Reduced space
space constraints for conventional cable identified (
hot spots so far)
- in-between tile nooses
- under mu-chambers
Design
Voltage drop
This
table lists voltage drops along the power distribution from power supply
to modules
Cable design
- For PP2 to PP3 conventional cable
- PP3 to power supply identical design with 4mm2 instead of 1mm2
conductors and 0.3 instead of 0.14mm2 conductors
low current - 0.14 mm2 conductors
- HV
- HV_ret
- V_cc_sense
- A_gnd_sense
- V_dd_sense
- D_gnd_sense
- TEMP_1
- TEMP_2 (barrel only)
- PIN_bias
- ILED_a
- ILED_b
- SELECT
- RESET
high current - 1mm2 conductors
Construction and tests on prototype
cable
A prototype cable for PP2 to PP3 has been produced by LEONI Gmbh, Germany,
for use in system tests,
beam tests and irradiations.
Technical specifications for this cable are available as
CERN Technical Specification number 522 rev 1 / 31.10.00.
The cable is available at CERN store under SCEM 04.71.01.010.7
Sections of this cable have been tested at CERN TIS for radiation and fire
behaviour. Results of these tests are
available under document TIS-TE/MTR/2000-02 (18.5.2000).
Both reports are combined
here into one PDF file.
Radiation test results: (conducted
by TIS)
Fire test results (conducted by LEONI/VDE)
