Transcript Hidden and naked charm in Belle (new charm spectroscopy?)

Henryk Palka, IFJ Krakow, DEPFET-Belle II meeting MPI, March 08, 2010
Low Voltage Supply and Regulation
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Henryk Palka, IFJ Krakow, DEPFET-Belle II meeting MPI, March 08, 2010
Low voltages for DEPFET
• 18 voltage lines x 40 half-ladders = 720 PS output channels
1) Can be prohibitive in price (100’s k€)
2) PSs 20-30m away from the ladders
 difficult (imposible?) to regulate voltage drop at the PS
in 2.3A lines
R= 5mΩ/m * 30m [10 mm2 cable]
+ 1.72*10-8 Ωm *0.5 m/(17*10-6 m *3.48*10-3 m)
= 150 mΩ + 145 mΩ = 295 mΩ
ΔV = 2.3A * 0.295Ω = 0.68 V (at V0=1.8V)
→ voltage regulators needed, near to the ladder
then the number of PS output channels/half-ladder can be
reduced, naively to 4 (+2.5V, +3.0V,+20V, -20V),
in practice to several channels
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Henryk Palka, IFJ Krakow, DEPFET-Belle II meeting MPI, March 08, 2010
VDDA 1.8 2.3
PS 3V, 5A VDDD 1.8 0.8
VDDIO 1.8 0.1
VJTAG 1.8 0.004
VDDIO 1.8 0.904
VDDC 1.2 0.5
Vclear_on 17 0.03
Vbulk
17 0
Vgate_off 13 0.03
PS 20V, 0.5A Vclear_off 8 0.03
Vsource
7 0.1
Vccg
70
Vgate_on 4 0.03
Vguard
?
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PS 2.5V, 2A REFIN
1.1 0.1
AMPLOW 0.35 1.5
Below Vmin of existing radhard
regulators. Use voltage dividers?
PS -20V, 0.5A
Static voltages, need any regulation?
(fixed voltages with no sensing?)
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Henryk Palka, IFJ Krakow, DEPFET-Belle II meeting MPI, March 08, 2010
DEPFET Voltages
DCD
name
VDDA
VDDD
REFIN
DGND
AGND
DHP
VDDIO
type
DCD analog
2*sensing
DCD digital
2*sensing
DCD analog ref
2*sensing
common digital gnd
analog ground
V
dV/V
I
dI/I
1,8
2%
2300
20%
1,8
2%
800
20%
1,1
2%
100
20%
0
0
800
2300
1,8
2%
100
20%
1,2
2%
500
20%
DGND
DHP IO rail
2*sensing
DHP core
2*sensing
digital gnd
0
600
SWITCHER
VDDS
DGND
VJTAG
digital supply
digital gnd
JTAG IO rail
3,3
0
1,8
4
4
4
common
VDDIO
1,8
DGND
common rail + DCD digital
2*sense
digital gnd
Vclear_on
Vclear_off
Vgate_on
Vgate_off
Vsource
Vccg
Vbulk
Vguard
Vbias
clear on
clear off
gate on
gate off
source
common clear gate
bulk
guard ring
backplane
VDDC
bias voltage
2%
904
0
1404
17
8
4
13
7
7
17
30
30
30
30
100
0
0
-20
0
20%
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Henryk Palka, IFJ Krakow, DEPFET-Belle II meeting MPI, March 08, 2010
Where to place the regulators:
Power unit
(rack)
x 40
Dock
DHH
~20m
~2m
regulators?
Half-module
~0.5m
regulators?
space?
Regulators placed at Docks:
-add less than 7% to overall resistance
-do not heat up the region which is already critical for cooling
-Less radiation hazard (the level O(108 n/cm2/yr) ?)
Henryk Palka, IFJ Krakow, DEPFET-Belle II meeting MPI, March 08, 2010
Use radiation tested regulators?
• Plain regulators are chip and available in all varieties
• Radiation tested are few:
- RHL4913A (STM) used in ATLAS, regulates down to
1.22 V, Imax=2A (3A in SMD package)
- LM117 (NS) used in CMS, min Vout=1.23V, Imax=0.8A
- RH1086 (Linear Tech.), used in Alice, CMS (?)
min Vout=1.23V, Imax=1.5A
-
MIC5209 (Micrel) min Vout=1.24V, Imax=0.5A
- 5950RH (M.S.Kennedy) min Vout=2.5V, Imax=5A
- AN1081 (Int. Rectifier) min Vout=1.26V, Imax=3A
None goes below 1.2 V
Availability is another concern
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Henryk Palka, IFJ Krakow, DEPFET-Belle II meeting MPI, March 08, 2010
RHFL4913A:
~5% of IL
goes into
sense wire
Rsense important!
•VIN = 3 - 12 V
•VOUT = 1.2 – 9 V
•Vd = ~1V
•Pmax = 15 W (~ VIN/VOUT)
•Occupies ~ 3.0 cm2 (+external)
ATLAS: remote sensing, protection:
over- voltage, current,
temperature
Monitoring
CAN Bus
Some experience at the Institute in using
this chip for ATLAS TRT regulator board
(Bartek Kisielewski)
Test board to study how it works for
Belle II conditions
More coll. needed to form a critical mass
Henryk Palka, IFJ Krakow, DEPFET-Belle II meeting MPI, March 08, 2010
Conclusions
• We ought to define
- voltages to be regulated by dedicated circuity
-
(mix of PS regulated and custom regulated? Nightmare?)
needed accuracy of the regulation and load currents ranges
which of the supply lines are current source/current sink
fix resistivity of the lines
which protocol for controls (GPIB, CANBus,…)
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