Download Powering issue

Serial Powering of Pixel Modules
T. Stockmanns, P. Fischer, O. Runolfsson and N. Wermes
Tobias Stockmanns, Universität Bonn
1
Vertex 2002, Kailua-Kona 7.11.2002
Why serial powering?
CC
or
CV
CV
Tobias Stockmanns, Universität Bonn
CV
CV
2
CV
CV
Vertex 2002, Kailua-Kona 7.11.2002
Power consumption
•
Every ATLAS - pixel module needs:
– 2 supply voltages:
Name
Voltage
Current
Power
VDDA
1.7 V
970 – 1290 mA
1650 – 2200 mW
VDD
2V
500 – 800 mA
1000 – 1320 mW
 1.5 - 2 A
Sum
Total detector
2V
6
power lines
per module
3500 A
(1750 modules)
– 1 HV bias connection
– 3 ground lines
Tobias Stockmanns, Universität Bonn
3
Vertex 2002, Kailua-Kona 7.11.2002
Cable
120 m
20 m
Power
supply
PP 3
3V
Add. 1 V
PP 2
0,5 V
cable costs
cable size
Total distance:
152 m
Maximum voltage drop:
6.5 V
1V
Optimum:
No cables at all
Pixel detector
9m
cable mass
0,5 V
0,55 V
PP 0
2,8 m
Modules
Tobias Stockmanns, Universität Bonn
PP 1
< 0,5 m
4
Vertex 2002, Kailua-Kona 7.11.2002
Parallel Powering
constant voltage
power supply
• For a stave of 13 modules:
constant voltage
power supply
VDDA
- power + sense lines:
- supply voltage:
Module 1
16
FE
- supply current:
FE
+ voltage
drop:
16
Tobias Stockmanns, Universität Bonn
5
VDD
Regulator
VDDA
VDD
104
2 V / 1,7 V
FE
- power consumption:
Module 2
Regulator
FE
26 A
47 W
226 W
Vertex 2002, Kailua-Kona 7.11.2002
Alternative: Serial Powering
I0
On chip
On chip
26 V
Module 1
16
• For a stave of 13 modules:
VDDA
FE
Constant
Current
Power
Supply
Module 2
2
- supply voltage:
26 V
16
2A
- power consumption:
52 W
+ voltage drop:
readout
20 V
shunt regulator
65 W
16
FE
24 V
FE
- supply current:
linear regulator
VDDreadout
24 V
- power + sense lines:
FE
Module 13
FE
2V
FE
readout
0V
Tobias Stockmanns, Universität Bonn
6
Vertex 2002, Kailua-Kona 7.11.2002
Pros and Cons
of both concepts
Parallel Powering
Serial Powering
Pros
Cons
• Individual control of each module
• Difficult to switch off a single module
• No risk for the full chain
• Risk to loose a full chain
• Possible noise crosstalk via power lines
Cons
Pros
• low voltage + high current  high
voltage drop
• high voltage + low current  low
voltage drop
• high total power of pixel detector
• lower power consumption of pixel
detector
• one power supply per module
• one power supply per chain
• large amount of cables
• less amount of cables
Tobias Stockmanns, Universität Bonn
7
Vertex 2002, Kailua-Kona 7.11.2002
Shunt regulators
•
•
•
•
10 shunt regulators built with commercial ICs
All of them operated in series
2 modified to work with the required voltage
water cooled
Tobias Stockmanns, Universität Bonn
8
Vertex 2002, Kailua-Kona 7.11.2002
Parallel readout of 2 serially
powered modules
PLL 1 + 2
PixDAQ 1 + 2
2A
VME - Crate
Linear Regulator
PCC
Module 2
Module 1
PCC
Shunt Regulators
Tobias Stockmanns, Universität Bonn
9
Vertex 2002, Kailua-Kona 7.11.2002
No influence on module
performance
Serial powered
Parallel powered
Threshold:
4700 eDispersion:
480 eNoise:
150e- / 250 e-
Threshold:
Dispersion:
Noise:
Tobias Stockmanns, Universität Bonn
11
4330 e300 e148 e-
Vertex 2002, Kailua-Kona 7.11.2002
Integration of regulators in
newest FE-chip
Shunt regulator
14000
12000
1,45
0
Output voltage [V]
-6C
0
21 C
10000
current [µA]
Linear regulator Iout = 60mA
8000
6000
4000
Slope = 1 / 33.4 
2000
0
1,40
minimum dropout voltage 0.285V
1,35
1,30
1,25
-2000
0,0
0,5
1,0
1,5
2,0
2,5
3,0
1,3
voltage [V]
1,4
1,5
1,6
1,7
1,8
1,9
2,0
2,1
2,2
Input voltage [V]
shunt regulator and linear regulator implemented and tested
in the newest radhard version of the FE-chip
Tobias Stockmanns, Universität Bonn
14
Vertex 2002, Kailua-Kona 7.11.2002
Threshold measurement
4 FE-I chips in parallel
1 + 2 chips in series
FEI
CC
CC
FEI
FEI
Threshold:
Dispersion:
Noise:
FEI
FEI
FEI
4680 e100 e264 e-
Tobias Stockmanns, Universität Bonn
Threshold:
Dispersion:
Noise:
15
FEI
4780 e105 e268 e-
Vertex 2002, Kailua-Kona 7.11.2002
Serial Powering
Sensorless Module
•
•
13 working chips
37120 working pixels
typ.
Threshold:
Dispersion:
(untuned!)
Noise:
4800 e1340 e-
1200 e-
214 e-
160 e-
Tobias Stockmanns, Universität Bonn
16
Vertex 2002, Kailua-Kona 7.11.2002
Summary
• Serial Powering of pixel detectors seems to be possible:
–
–
–
–
Feasibility of serial powering proven with external regulators
Regulators implemented into the new radiation hard FE-chips
Internal regulators tested on single chips and modules
electrical performance very similar  hope that the differences in
noise disappear with new version of regulators
• Next steps:
– Using several modules in a series
– Measuring the performance of the modules depending on
different situations
– Testing possible failure scenarios
Tobias Stockmanns, Universität Bonn
17
Vertex 2002, Kailua-Kona 7.11.2002
„On Module“ – Serial Powering
• On each side of a module the FE-chips are connected in series
 Current consumption goes down by a factor of 8 with an 8times higher voltage
• Opposite FE-chips are on the same DC-potential
Constant
Current
2V
4V
6V
8V
10 V
12 V
14 V
16 V
2V
4V
6V
8V
10 V
12 V
14 V
16 V
Tobias Stockmanns, Universität Bonn
18
Vertex 2002, Kailua-Kona 7.11.2002
„On Module“ – Serial Powering
• Implementation:
– AC-coupling between FE-chips and MCC necessary
– Special sensor design necessary
• Disadvantage:
– More complicated module design
• Advantages:
– low current consumption
– no risk of loosing a chain of modules
– individual module operation like in parallel powering
Tobias Stockmanns, Universität Bonn
19
Vertex 2002, Kailua-Kona 7.11.2002