Transcript Part 1 - GLAST at SLAC

GLAST LAT Project
Gamma-ray Large
Area Space
Telescope
Tower Power Supply Review Sept 22, 2003
GLAST Large Area Telescope:
Electronics, Data Acquisition &
Flight Software
TEM Power Supply
Part 1
Gunther Haller
Stanford Linear Accelerator Center
Manager, Electronics, DAQ & FSW
LAT Chief Electronics Engineer
[email protected]
(650) 926-4257
Gunther Haller
Part 1, Version 3
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GLAST LAT Project
Tower Power Supply Review Sept 22, 2003
LAT Electronics Physical
TKR Front-End Electronics (MCM)
ACD
ACD Front-End Electronics (FREE)
TKR
CAL Front-End Electronics (AFEE)
CAL
Global-Trigger/ACD-EM/Signal-Distribution
(GAS) Unit*
Spacecraft Interface
Unit
– Storage Interface
Board (SIB):
EEPROM
SC MIL1553
control & data
– LAT control CPU
– LAT
Communication
Board (LCB): LAT
command and
data interface
16 Tower Electronics Modules
– DAQ electronics module (DAQ-EM)
– Power-supplies for tower electronics
3 Event-Processor Units (2+1 spare)
– Event processing CPU
– LAT Communication Board (LCB)
– Storage Interface Board (SIB)
EPU-1
EPU-2
Pw r Dist. Box
spare
spare
GASU
spare
spare
spare
SIU-P
SIU-R
EPU-3
Power-Distribution Unit (PDU)*
– Spacecraft interface,
power
– LAT power distribution
– LAT health monitoring
* Primary & Secondary Units shown in one chassis
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GLAST LAT Project
Tower Power Supply Review Sept 22, 2003
LAT Power Distribution
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SIU’s are powered directly by
spacecraft on dedicated feeds
Rest of LAT electronics is powered via
SC main feed to PDU
– Prime and redundant SC feeds
connected to prime and redundant
PDU circuits
PDU controls power to towers, to
GASU, and to EPU’s
– Either PDU circuit can supply
power to clients
GASU switches power to ACD
– Prime and redundant GASU circuit
can supply power to ACD
TEM’s switch power to TKR/CAL
– No redundancy in tower power
system
Heater power circuit not shown
Gunther Haller
SC Main
Feed P
EPU
P0
EPU
P1
SC SIU P
Feed
SC Main
Feed R
SC SIU R
Feed
SIU
P
EPU
R
PDU
Board P
SIU
R
PDU
Board R
PDU
Power Distribution
ACD PS
P
TEM
0
Tower
PS
TEM
DAQ
C
A
L
T
K
R
GASU
DAQ P
T
K
R
GASU
DAQ R
ACD PS
R
TEM
14
TEM
1
Tower
PS
TEM
DAQ
C
A
L
Power Distribution
Prime
Redundant
GASU
Tower
PS
TEM
DAQ
A
C
D
A
C
D
A
C
D
0
1
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Part 1, Version 3
C
A
L
T
K
R
TEM
15
Tower
PS
TEM
DAQ
C
A
L
T
K
R
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GLAST LAT Project
Tower Power Supply Review Sept 22, 2003
Requirements
• Requirements are in LAT-SS-01281
• Supply power to Calorimeter, Tracker, TEM-DAQ systems
– Main drivers are
• Low output noise, down to 100 uV RMS, 1 mV p-p
– Powers input amplifiers of CAL and TKR front-end
electronics
• Low output voltage, down to 1.5 V
– TKR input amplifier runs of 1.5V to meet power/thermal
requirements for 850k channels
• High overall efficiency
– Total LAT power limited, also thermal limits because of
radiator area
• Adjustable high-voltage supply up to 150V
– Silicon strip TKR detectors (up to 150V) and CAL Sidiodes (up to 100V) need remotely adjustable depletion
voltages
Gunther Haller
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GLAST LAT Project
Tower Power Supply Review Sept 22, 2003
Detailed Requirements
• See LAT-SS-1281,
(display the requirement pages in that document for
discussion)
Gunther Haller
Part 1, Version 3
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GLAST LAT Project
Tower Power Supply Review Sept 22, 2003
Tower Power Supply Module
TRKEnable
Tracker Voltages
28V from
PDU
461-Filter
HV-I MON
Calorimeter
Voltages
CALEnable
TEM-DAQ
Voltages
To PDU
Ana-1.5V-A (~1A)
Ana-1.5V-B (~1A)
Ana-2.5V-A (~1A)
Ana-2.5V-B (~1A)
Dig-2.5V-A (~0.3A)
Dig-2.5V-B (~0.3A)
HV-150Vadj- (~1uA)
Ana-3.3V (~0.4A)
Dig-3.3V (~0.96A)
HV-100Vadj- (~1uA)
HV-I MON
Dig-3.3V-del (~0.6A)
Dig-2.5V (~0.4 A)
Currents are measured
values
Temp, 3.3V TEMV Sensors
I-Total MON
Gunther Haller
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GLAST LAT Project
Tower Power Supply Review Sept 22, 2003
Tracker Electronics
GTRC ASIC
•
GTFE ASIC
TKR sub-system electronics
• Si-Strip Detectors
• 24 GTFE (GLAST Tracker Front-End) ASICs (1,536 signal channels)
• 2 GTRC (GLAST Tracker Readout Controller) ASICs
• MCM (Multi-Chip Module)
• Flex-cables
•
Total of 36 (4 sides, 9 each) MCM’s per tower power supply module
– Power is routed via TEM DAQ board from TEM-PS to TKR
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GLAST LAT Project
Tower Power Supply Review Sept 22, 2003
Calorimeter Electronics
GCRC ASIC
GCFE ASIC
•
CAL sub-system electronics
• Diodes
• 48 GCFE (GLAST Calorimeter Front-End) ASICs
• 4 GCRC (GLAST Calorimeter Readout Controller) ASICs
• AFEE (Analog Front-End Electronics) board
•
Total of 4 (4 sides, 1 each) AFEE’s per tower power supply module
– Power is routed via TEM DAQ board from TEM-PS to CAL
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GLAST LAT Project
Tower Power Supply Review Sept 22, 2003
DAQ Electronics
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Tower Electronics Module DAQ board
Total of 1 TEM DAQ per tower power supply module
Gunther Haller
Part 1, Version 3
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GLAST LAT Project
Tower Power Supply Review Sept 22, 2003
Interfaces
• Tower Power Supply interface via two connectors to
– Power Distribution Unit
• Incoming 28V +/- 1V
• Monitoring to PDU
• For EGSE desire to be able to remotely adjust front-end
voltages
– Tower Electronics Module
• Supply voltages to TKR, CAL, and TEM
• HV currents and total current monitoring
• Enable signals for CAL and TKR system
• Analog set voltage for HV supplies
– LAT-SS-1281
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GLAST LAT Project
Tower Power Supply Review Sept 22, 2003
Enclosure
Tower Electronics Module
Gunther Haller
PSU
TEM – PSU Stack
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GLAST LAT Project
Tower Power Supply Review Sept 22, 2003
Development
•
•
When SLAC electronics group started getting involved in LAT
electronics (at approval of project)
– Efficiency of power supplies of tower was supposed to be about
70% overall to meet power numbers
– Tried to get more power, but denied
• SC interface issue
• Problem with getting rid of heat (radiator areas)
– Worked to even more optimizing CAL, TKR, DAQ power (ASIC’s
and other components),
• Reduced power supply efficiency required to 62% (still very
challenging, but that was it)
Standard solution with “catalog” 28V/3.3V DC/DC converter and linear
regulators were explored but not realistic
– At tower load of ~25W, needed at least 40W (at 3.3V!) converter,
(no 1.5V or 2.5V converter available at that time)
• At LAT load: efficiency is 65% to 70%. just for 28->3.3V part
• Need to generate 2.5V and 1.5V via linear regulators from 3.3V
• Results in 47-50% overall efficiency (including HV supplies)
• Over allocation: between 88W and 126W
Gunther Haller
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GLAST LAT Project
Tower Power Supply Review Sept 22, 2003
Development (Con’t)
• First solution
– Pursued full-custom vendor design
• Proof-of-principle prototype was designed and built,
based on synchronous rectification
• Measured 87% efficiency of 28V/1.5V supply!
• Met power requirement (status at CDR)
• Went out for bids (Responses came in after CDR)
• Bid returned were not affordable, by a lot
• Not a working solution
Gunther Haller
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GLAST LAT Project
Tower Power Supply Review Sept 22, 2003
Development (Con’t)
•
Beginning of 04
– International Rectifier proposed new Z-series converter, based on
synchronous rectification
– 28V/3.3V converter with up to 82% efficiency at full load, great device
compared to others on the market
– New Device (no flight heritage yet), assembly of two PC-boards and
controller hybrid
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GLAST LAT Project
Tower Power Supply Review Sept 22, 2003
Development (Con’t)
•
– Needed to be optimized for LAT load (Z-series is optimized for
20A/3.3V (~82%), LAT only needs 40% of that -> efficiency drops
considerably)
– Put contract in place late spring 03 (as back-up)
– However still does not meet power allocation by > 30W
– Prototypes to be delivered late Fall 03
– On order, but cancelable (need to decide end of 9/03 with penalty
of 10%)
– Risk that calorimeter 3.3V analog is connected to DAQ TEM 3.3V,
very hard to filter low frequency noise from DAQ
Need to decide by end of 9/03 to avoid further penalty
Gunther Haller
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GLAST LAT Project
Tower Power Supply Review Sept 22, 2003
Development (Con’t)
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Spring 03:
Surveyed commercial DC/DC converters and evaluated for potential
radiation performance (CMOS versus bipolar technology, IC feature
sizes)
Radiation tested several DC/DC integrated circuit devices at Legnaro
and TAMU (in Summer 03)
Selected MAX724/726 devices as base-line
Designed circuit board for low-voltage circuits using MAX726
Designed high-voltage circuit (all along needed to be full-custom
since nothing available as a catalog item)
– Received also proof-of-principle HV design from vendor (at CDR)
– Went out for bids
– Was not affordable, by a lot
– Got previous flight design from Art Ruitberg (GSFC)
– Started new design at SLAC (Dieter Freytag), eliminating
transformers
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GLAST LAT Project
Tower Power Supply Review Sept 22, 2003
Development (Con’t)
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Designed/simulated high-voltage circuit by 7/03
Laid out HV-only PC board, fabricate/loaded by 8/03
Designed/laid-out/fabricated full TEM-PS by end of August 03
Started testing 9/03
Review 9/22/03
Gunther Haller
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