Download - FP420 Low and high voltage supply Henning E. Larsen, INFN [email protected] Dec. 2006. rev.2
FP420Low and high voltage supply
Henning E. Larsen,
INFN
Dec. 2006. rev.2
Revision information
• Since I made the slides, the frontend has gone from 6 to 4 detectors/superlayer. I have as far as possible tried to take this fact into account in this revised version.
HV-LV supply segmentation
Damage depends on distance from the beam. Required bias voltage and current increase with radiation dose.
Drawing: From Ray Thompson
PT1000 Temperature sensor?
Pixels:50x400um and 400x50um
MCC: Module Controller Chip
1 Superlayer =
2 Hybrids/Blades4 2D detectors1 MCC1 Read-out interface
Now only 2 det.
Specification for LV for 1 superlayer
PixChips/4 Voltage Current Current limit
Analog 1.6-2.0VNom 2V
5-70mA 100mA
Digital 1.5-2.5VNom 2V
1% occupancy: 40-50mA 10% occupancy: 60-70mA
100mA
MCC/1 Voltage Current Current limit
Digital 1.8-2.5V 120mA-150mA 170mA
Ripple at 1MHz is critical. Remote on/off. Monitor current.Digital supply for Pixelchip and MCC is common as seen from supply.
4 PixChips + 1 MCC
+ Read-out?
Voltage Current Current limit
Analog 1.6-2.0V 20-280mA 310mA
Digital 1.8-2.5V 1% occ 280mA-350mA
10% occ 360mA-430mA
480mA
Monitor resolution <20mV <10mA
DEC 2006:Notice change from 6 to 4 detectors per superlayer
Specification for HV supply
4 detectors
2 voltages
Voltage Current Current limit
-10-150V
0-120V(*)
<1mA 1mA
Monitor
Resolution
<1V 1μA Voltage is negative, but floating.
Referenced to AVDD on PIXELCHIP, not GND
HV connection diagram used in Atlas
Source: Maurice Garcia-Sciveres
DEC 2006:
Notice change from 6 to 4 detectors per superlayer
(*) -120V is also sufficient.
One of 4 stations
Counting inventory:
Super layers: 2 experiments * 2 zones * 5 pockets * 5 superlayers=100 super layers
LV supplies: 100 super layers * 2 voltages = 200 channels
HV supplies: 100 super layers *2 voltages = 200 channels
Crate count is preliminary
Overall system geography
Commercial: Wiener solution A
• 2x4 Mpod-like systems (8U,19” each) will be arranged to provide the requested voltages over 500 m distance,
• Located in the counting rooms and will host both HV and LV modules. • 2 cable pipes with 10 cm section (or probably less) are needed. • The Mpod will require custom -150V modules. .
4*2 Mpods with 80ch each.
Location: Counting room
Mpod
x 8
•150k€ for Mpod’s
•100k€ for cables
Now only 2 HVNow only 2 HV
Commercial: Wiener solution B
• 2x10 Maraton-like radiation tolerant systems (3U) will provide LV and operate close to the detectors.
• 2x2 Mpod-like devices will supply HV from the counting rooms.
• This solution requires a customization of Maraton in order to optimize it for low currents.
• The Mpod will require custom -150V modules.
• Cost not yet discussed.
One per pocketMpod
x 2 x 5
One per pocketOne per crystat
1 Maraton 1 Maraton
Now only 2 HV
Commercial: Wiener solution C
• 2x22 Maraton-like system will provide HV and LV and operate close to the detectors.
• Simple cable • These systems will be optimized for the given current range. • Need customization for -150V modules• Proven radition tolerance: 722Gy, 8 1012n/cm2
• Cost not yet discussed
1 Maraton
2.2 crates per pocket
H=3U=131mm
1 Maraton
2.2 crates per pocket
x 11x 11
Now only 2 HV
CMS/Atlas counting room
Commercial: Caen
SY1527
A1676A
Crate Ctl
A1676A
Crate Ctl
A3486
2x48V
Power
A3486
2x48V
Power
Atlas or CMS
Slow control
EASY 3000
A3009
12ch
LV
A3009
12ch
LV
A3009
12ch
LV
A3009
12ch
LV
A3009
12ch
LV
EASY 3000
A3501
12ch
HV
A3501
12ch
HV
A3501
12ch
HV
A3501
12ch
HV
A3501
12ch
HV
A3501
12ch
HV
A3501
12ch
HV
FP420
FP420
FP420
FP420
FP420
LHC Tunnel
EASY 3000
A3009
12ch
LV
A3009
12ch
LV
A3009
12ch
LV
A3009
12ch
LV
A3009
12ch
LV
EASY 3000
A3501
12ch
HV
A3501
12ch
HV
A3501
12ch
HV
A3501
12ch
HV
A3501
12ch
HV
A3501
12ch
HV
A3501
12ch
HV
FP420
FP420
FP420
FP420
FP420
Cryostat 1 Cryostat 2
Commercial: Caen, pictures
SY1527EASY 3000
Not to scale
A3009 A3501
Commercial: Caen
A3009 LV
A3501 HV
A3009 LV
A3501 HV
A3486 48V Power
•Modules 220k€
•Cable ~20k€
•Delivery not possible before summer 2008 due to LHC production bottle neck. Only few samples by mid 2007.
•CAN bus link has to be extended to 500m. This is not yet tested
•High voltage only up to 120V
Cable:500m
Commercial: Eplax GmbH
• Entirely custom design based on their >20year experience with standard power supplies and our specification
• No experience with radiation tolerant supplies.
• Non recurring engineering cost: 25k€• Supply for 1 superlayer: 900€• Total cost: 115k€ (excl cables)
LV supply: simulation model with long lines
•Current transients are mainly limited by capacity at the load.
•Simulation shows a 500m+500m cable with 20% current change for C=1µ, 5µ, 50µF
Conclusion:
•500m++ of LV cables is not feasible
Simulation, Low voltage, 500m cable
LV supply using LHC4913
If we make our own custom solution a regulator like LHC4913 is very convenient and unique. It is now being ported to a military/space qualification => higher cost, but presumably available.
1. Rad hard.
2. Extensively used at LHC detectors.
3. Remote sense on the positive and negative supply. This means it can compensate for resistive cable voltage drop. This means that with LHC4913, a thinner cable can be used.
4. Adjustable current limit.
5. ON/off switch input.
ADC’s: DCUF Detector Control Unit (CMS)
•CMS central tracker for the monitoring of some embedded parameters like supply voltage and currents on the front-end read-out modules•Is available in the quantity we need
HV principle diagram
+
Vbias
-
Cable
VinαIbias
αVbias
Ibias
Transformer+rectifier
R3
R2
R1R1
R2
Passtransistor
DAC
•Simple linear regulator to make radiation tolerance easier to implement with COTS
•Monitor, remote control, galvanic isaolated
Galvanicisolation
ADC’s
“Home made” in-tunnel-solution
cost estimate
Modules 120k€
Cable 20k€
Item unit cost Units in total
LV-HV boards
PCB 150 €Components 300 €Mechanics 30 €Connectors 70 €Mounting 150 €
Total 700 €120 700 € = 84,000 €
CrateBackplane 300 €Connectors 100 €Mechanics 200 €
Total 600 €24 600 € = 14,400 €
Crate controllerPCB 150 €Components 300 €Mechanics 30 €Connectors 70 €Mounting 150 €
Total 700 €24 700 € = 16,800 €
Cables
? ?
Total cost 115,200 €
Total cost CMS+ATLAS 120,000 €
?? To be figured out but much much less than solution with
# Pcs+ 20%spar
Location for service electronicsUntil today we thought:• If the LV electronics should stay within some 20m from the detectors, there are only two possible locations (ref
Daniela Macina):
– Below the new cryostat, where the radiation level is estimated at about 700 Gy per year of running at full luminosity;
– Below or near the adjacent magnets, where the radiation is much lower and estimated at about 15 Gy per year, but where there are already other things.
Space for service electronics.•Few meters of cable•Radiation level?•Shielding possibility?
Space for electronics needing close proximity to detectors
At mechanics meeting 29/9/06 we saw:
FP420 detectors
Issues to finalize• Location of support electronics in tunnel. Favour of putting it under the
adjacent magnets. Cable length about 10m.
• Radiation level to expect. There ought to be simulations done with shielded cryostat at fp420 to evaluate the dose. Current assumption is 15GY/y
• Home made or commercial solution?
• Cable distances from fp420 to the counting room for all 4 stations have to be estimated more precisely than the current 500m
• Specification of number of channels
• Specification of LV supply for superlayer readout part (Opto board).
• Need for temperature monitor of FE for the cooling system. Where should it be serviced? If in the HV-LV unit, we need define a local interface with cooling as this cant go through slow control.
• Are there any requirement for:
– Hardware interlocks related to temperature?
– Graceful power down =UPS backup?
Conclusions
• Some interesting solutions from industry. Some almost off the shelf.
• We have an outline of how to build the LV-HV our selves but chip supply is critical.
• We need to make up our minds if we buy or build ourselves.
• We are opting for putting the LV/HV crates under the adjacent magnets