GLAST LAT Project Tower Power Supply Review Sept 22, 2003
Gunther Haller Part 2, Version 4 1
GLAST Large Area Telescope:GLAST Large Area Telescope:
Electronics, Data Acquisition & Flight Software TEM Power SupplyPart 2
Gunther HallerStanford Linear Accelerator CenterManager, Electronics, DAQ & FSWLAT Chief Electronics Engineer
[email protected](650) 926-4257
Gamma-ray Large Gamma-ray Large Area Space Area Space TelescopeTelescope
GLAST LAT Project Tower Power Supply Review Sept 22, 2003
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TeamTeam
• High-Voltage– Dieter Freytag (SLAC)– Original assist by Art Ruitberg (GSFC)
• Low Voltage– Dave Nelson (SLAC)– Assist by Dieter Freytag, Joszef Ludvig (SLAC)
• Combined Board– Dave Nelson (SLAC)– Mark Freytag, Dieter Freytag (SLAC)
• Layout– HV section: Cathy (SLAC)– Combined Board: Tung Phan (SLAC)
• Assembly/Parts– Lupe Salgado (SLAC)
• Mechanical/Thermal– Dave Nelson, Jobe Noriel, Dave Tarkington (SLAC)
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Top-Level BlocksTop-Level Blocks
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Filter SectionFilter Section
Filter28V from PDU
28-V filtered
• Uses standard MIL-461 filter for flight. Board can also be loaded with commercial filter for EGSE versions (to other sub-systems)
• See Schematic “Filter” block
GLAST LAT Project Tower Power Supply Review Sept 22, 2003
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TEM DAQ SectionTEM DAQ Section
Delay28V filtered
3.3V Converter
2.5V Converter
3.3 V TEM DAQ
2.5 V TEM DAQ
• Uses delay circuit to turn-on 3.3V to ACTEL FPGA’s on TEM DAQ after 2.5V core voltage (see ACTEL alert)
• See Schematic “DAQ” block
GLAST LAT Project Tower Power Supply Review Sept 22, 2003
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CAL SectionCAL Section
28V filtered3.3V Converter
3.3V Converter
3.3 V CAL analogFilter
3.3 V CAL digitalFilter
Switch
28V switched
CAL enable
HV Converter
30V-100V
Cal set voltage (0-2V)
• HV starts at 30V• HV and LV are switched on/off together (no independent HV switch)• PC-board designed so linear regulator can be added in case noise is not low enough
– Either International Rectifier low-drop linear regulator– Regulator with single NPN
• Baseline is without linear regulator because– Higher efficiency– Omnirel max output voltage is 3.2V
GLAST LAT Project Tower Power Supply Review Sept 22, 2003
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TKR SectionTKR Section
28V filtered1.5V Converter
1.5 V-A TKR analogFilter
Switch
28V switched
TKR enable
HV Converter30V-150V
TKR set voltage (0-2V)
1.5V Converter1.5 V-B TKR analog
Filter
2.5V Converter2.5 V-A TKR analog
Filter
Filter2.5 V-A TKR dig
2.5V Converter2.5 V-B TKR analog
Filter
Filter2.5 V-B TKR dig
• HV starts at 30V• HV and LV are switched on/off together (no independent HV switch)• PC-board designed so linear regulator can be added in case noise is not low enough
– Either International Rectifier low-drop linear regulator– Regulator with single NPN
• Baseline is without linear regulator because– Higher efficiency– Omnirel min input voltage is 2.9V (high for 1.5V output, loose 50% of power in linear regulator)
GLAST LAT Project Tower Power Supply Review Sept 22, 2003
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Typical Low-Voltage Operating CircuitTypical Low-Voltage Operating Circuit
• For 3.3V and 2.5V: set by resistor ratio according to data-sheet• For 1.5V output:
– Can’t just select resistor divider since internal reference is 2.2V– Solution: sum in current (resistor from external zener diode) at FB node to offset feed-back
voltage
R
Vref
For 1.5V output
GLAST LAT Project Tower Power Supply Review Sept 22, 2003
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High-Voltage DC/DC Converter (Simplified)High-Voltage DC/DC Converter (Simplified)
• For details, see schematic
GLAST LAT Project Tower Power Supply Review Sept 22, 2003
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TEM-PS BoardTEM-PS Board
Maxim High-VoltageConnector to TEM
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High-Voltage SuppliesHigh-Voltage Supplies
• SLAC (Dieter)– Circuit Design & Simulations (PSPICE) – PC board circuit debug/circuit modifications– Noise, stability measurements (see example plot)
• GSFC (Art)• Got loaded board from SLAC• Phase margin measurements (see plot)• Consultation
GLAST LAT Project Tower Power Supply Review Sept 22, 2003
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Signal at Coil and at Switching TransistorSignal at Coil and at Switching Transistor
• Courtesy of Dieter Freytag
GLAST LAT Project Tower Power Supply Review Sept 22, 2003
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High Voltage NoiseHigh Voltage Noise
• Courtesy of Dieter Freytag, with RC Filter at output, RMS ~11mV, dominated by 60 Hz-line (need to be remeasured in TPS enclosure)
GLAST LAT Project Tower Power Supply Review Sept 22, 2003
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High-Voltage Amplitude/PhaseHigh-Voltage Amplitude/Phase
• Courtesy of Art Ruitberg
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Low-Voltage SuppliesLow-Voltage Supplies
• Mostly Dave Nelson (SLAC)
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TKR 1.5V when TKR is turned onTKR 1.5V when TKR is turned on
• 28V powered• TKR 1.5V supply output when TKR supplies are turned-on via TEM DAQ enable signal
GLAST LAT Project Tower Power Supply Review Sept 22, 2003
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CAL 3.3V when 28V is turned onCAL 3.3V when 28V is turned on
• CAL 3.3V analog output when 28V supply is turned on (CAL already enabled)
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Step into FeedbackStep into Feedback
• TKR 1.5V response when 200mW step is applied to feed-back• Damped
GLAST LAT Project Tower Power Supply Review Sept 22, 2003
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Step into feedback with 50nFStep into feedback with 50nF
• TKR 1.5V response when 200mW step is applied to feed-back• Better response
GLAST LAT Project Tower Power Supply Review Sept 22, 2003
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Amplitude/Phase of TKR 1.5VAmplitude/Phase of TKR 1.5V
Tracker 1.5 Volt Phase Margin
-30
-20
-10
0
10
20
30
40
50
1.0E+02
1.6E+03
3.1E+03
4.6E+03
6.1E+03
7.6E+03
9.0E+03
1.1E+04
1.2E+04
1.4E+04
1.5E+04
Freq - Hz
Gai
n -
dB
-200
-150
-100
-50
0
50
100
150
200
Ph
ase
- D
egre
e
Gain
Phase
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Phase Margin Cal 3.3 Analog
-10
0
10
20
30
40
50
60
701.0E+00
4.1E+01
8.1E+01
1.2E+02
1.6E+02
2.0E+02
2.4E+02
2.8E+02
3.2E+02
3.6E+02
4.0E+02
Freq Hz
Gai
n d
B
-150
-100
-50
0
50
100
150
200
Freq Hz
Ph
ase
Deg
rees
Amplitude/Phase of CAL 3.3VanalogAmplitude/Phase of CAL 3.3Vanalog
• 54 degree phase margin
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CAL 3.3V analog Noise SpectrumCAL 3.3V analog Noise Spectrum
Cal 3.3 Analog Noise Spectrum
-0.1
0
0.1
0.2
0.3
0.4
0.50.0E+00
1.0E+05
2.0E+05
3.0E+05
4.0E+05
5.0E+05
6.0E+05
7.0E+05
8.0E+05
9.0E+05
1.0E+06
Freq - Hz
No
ise
- u
V/S
qrt
(Hz)
* Plot is baseline subtracted
• Very good performance
GLAST LAT Project Tower Power Supply Review Sept 22, 2003
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TEM DAQ 3.3V Noise SpectrumTEM DAQ 3.3V Noise Spectrum
TEM 3.3 Volt Noise Spectrum
-20
0
20
40
60
80
100
120
140
160
180
0.0E+00
2.0E+05
4.0E+05
6.0E+05
8.0E+05
1.0E+06
1.2E+06
Freq - Hz
No
ise
- u
V/S
qrt
(Hz)
* Plot is baseline subtracted
• TEM digital has no LC filter on TEM PS
• Still very good performance