High Voltage MUX for ATLAS Tracker Upgrade EG Villani STFC RAL on behalf of the ATLAS HVMUX group...
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Transcript of High Voltage MUX for ATLAS Tracker Upgrade EG Villani STFC RAL on behalf of the ATLAS HVMUX group...
High Voltage MUX forATLAS Tracker Upgrade
EG Villani STFC RALon behalf of the ATLAS HVMUX group
TWEPP-14, 22 – 26 Sept. 2014
• HV MUX motivation and principle
• HV MUX devices requirements
• Real time test system and test results
• Conclusions
Outline
TWEPP-14 25/09/20141
ATLAS Phase II Tracker Upgrade
Challenges facing HL-LHC silicon detector upgrades
•Higher Occupancies ( 200 interactions / bunch crossing)
⤷ Finer Segmentation•Higher Particle Fluences ( 1014 outmost layers to 1016 innermost layers
⤷ Increased Radiation Tolerance ( 10 increase in dose w.r.t. ATLAS )
•Larger Area (~200 m2)⤷ Cheaper Sensors
•More Channels⤷ Efficient power/bias distribution / low
material budget
Phase 2 (HL-LHC)Replacement of the present TransitionRadiation Tracker (TRT) and Silicon Tracker (SCT) with an all-silicon strip tracker
Conceptual Tracker Layout
Short Strip (2.4 cm) -strips (stereo layers):Long Strip (4.8 cm) -strips (stereo layers):
r = 38, 50, 62 cmr = 74, 100 cm
From 1E33 cm-2 s-1 …to 5E34 cm-2 s-1
TWEPP-14 25/09/2014
HV distribution in ATLAS Upgrade
The ‘ideal’ solution would be one HV bias line for each sensor:• High Redundancy;• Individual enabling or disabling of sensors and current monitoring;But the increased number of sensors in the Upgraded Tracker implies a trade off among material budget, complexity of power distribution and number of HV bias lines.• Use single (or more) HV line to power all sensors in a ½ stave and use one HV switch under DCS control for each
sensor to disable malfunctioning detectors.
2
HV SW
HV SW
The Stave concept andHV distribution in ATLAS Upgrade
3
~ 1.2 metersBus cable
Hybrids Coolant tube structure
Carbon honeycomb or foam
Carbon fiber facingStave Cross-section
A Stave250
• Designed to reduce radiation length Minimize material by shortening cooling path 13x2 Modules glued directly to a stave core with
embedded pipes• Designed for mass production
Simplified build procedure Minimize specialist components Minimize cost
TWEPP-14 25/09/2014
TWEPP-14 25/09/20144
HV distribution in ATLAS Upgrade
TWEPP-14 25/09/2014
HV devices requirements
5
High Voltage switches strip detector requirements:
• Must be rated to 500V plus a safety margin;
• Must be radiation hard, nominal maximum expected 1x1015 neq/cm2 , 30Mrad (Si) for end cap. Multiply by (up to) 2 to include safety margin;
• On-state impedance Ron << 1kΩ // Ion 10mA (for irradiated sensors)
• Off-state impedance Roff >> 1GΩ // Ilkg << Isens
• Must be unaffected by magnetic field;
• Must maintain satisfactory performance at -30 C;
• Must be small (area constraint) and cheap (around 1E4 needed)
TWEPP-14 25/09/2014
HV devices investigatedHV Si, SiC and GaN based devices are being investigated
6
FAILED
FAILED
FAILED
FAILED
FAILED
FAILED
PASS – need conf.
T.B.T.
FAILED
FAILED
FAILED
PASS – N.A.
FAILED
TWEPP-14 25/09/2014
BackgroundPCB JFETsIds Igs
Ids
Vg
VgVg
Pre
irrad
iatio
n
JFET3
JFET4
Si JFET 2N6449Vds=285V
Vds=150V
PCB JFETsIds Ig Ids Ig
Vgs
JFET3
Vgs
JFET4
Post
irra
diati
on
7
TWEPP-14 25/09/2014
Real Time HV devices radiation tests
8
• Real time HV devices test system: it allows monitoring devices’ behaviour when irradiated• Real time Monitoring of rds and Ids vs. Vgs vs. particle fluence• Data are saved at 1 sample/sec for offline analysis • Two devices simultaneously, it can be used for generic real-time testing of devices under
radiation
IEEE488/USB2602
½
HV Vds and Ids tot
Vgs and Igs
Is
2602 ½
2602 ½
Is
15 m
Source meters
Q1 Q2
HV 2410
2602 ½
PC - LabviewParticle Beam
TWEPP-14 25/09/2014
HV mounting frame
9
Plexiglas Frame with X-Y adjustments to mount DUT HV devices.
PCB to hold up to 4 HV devices
PCB in the cool box
cool box
TWEPP-14 25/09/2014
HV mounting frame
10
Beam alignment checked with photo film on area where DUTs are placed
cool box
Level of radiation near the cool box after an irradiation test.
TWEPP-14 25/09/2014
HV devices radiation tests
11
• A number of HV devices tested at Birmingham last weeks, including:• EPC2012 (GaN FET)• CPMF-1200 (SiC MOSFET)• 2N6449 (Si JFET)
EPC2012
CPMF-1200
2N6449
EPC2012
TWEPP-14 25/09/2014
Irradiation test synopsis
12
EPC2012
EPC2012: rds @ constant mA’s test; Vds test at 150 V, 1mA compliance, Vgs =[-1, 3]V/20mV
time
RAD RAD RAD RAD RAD RAD RAD RADRAD RAD
Annealing + Ids plots: 5 mins
Rds measurement: 1 min
EPC2012: • 20 irradiation phases, 0.5 minute/ each @ Beam current 0.2 μA = 1.25e12 p+ /sec.• Rest phases in between irradiation phases around 5 minutes• Ids bias current increasingly higher, to emulate sensors leakage with dose
4 6 8 10 10 10 10 10 10 10 Rds measurement mA
TWEPP-14 25/09/2014
time
13
RAD RAD RAD RAD RAD RAD RAD RADRAD RAD
* At Beam current 0.2 μA = 1.25e12 p+ /sec.* For 26MeV p+ 2e15 1MeV n-eqv in ≈ 533 seconds (in Si – no data for GaN)* 20 irradiation phases of 30 seconds/each = 2.25e15 1MeV n-eqv (estimated MAX fluence for Strips is 2e15 1MeV n-eqv, including x2 safety factor)
* Max ΔT ≈4.5°C/sec
HV devices radiation tests beam sequenceAnnealing + Ids plots: 5 mins
Rds measurement: 1 min
TWEPP-14 25/09/2014
Constant Ids for rds measurement
14
EPC devices radiation tests results
Irradiation phases
Vgs sweep
DUT1/2 alternately ON
TWEPP-14 25/09/201415
EPC devices radiation tests results
Vgs sweepIrradiation phases
Is1, Is1
Magnified Time plots of board B DUTs Is1/2 during the radiation test.
Vds
TWEPP-14 25/09/201416
EPC devices radiation tests results
Irradiation phases 30 sec/each
Vgs sweep
Irradiation phases (30 + 30 sec.)
Time plots of board B DUT 1 Ig during the radiation test.
TWEPP-14 25/09/2014
EPC devices radiation tests results
Average Ig and 1 @Vσ gs=3V (device fully on).Average and 1 deviation Iσ s and Ig Leakage current @Vds=150V, Vgs=0V.
17
Vds=150V Vgs=3V
Average rdson < 2Ohm @Vgs=3V
TWEPP-14 25/09/2014
•We could use HV devices rated for lower voltage than needed and stack them on each other to achieve higher voltage switching• the biasing circuit needs careful designing, to avoid overvoltages and / or excessive leakage•Modeled circuit with parasitic resistor values taken from measurements of our own EPC devices.
18
Stacked configuration for high voltages
Not part of circuit; just mimics actual measured leakage currents
Also not part of circuit
TWEPP-14 25/09/201419
Stacked configuration for high voltages
Vload simulated
Vload measured
TWEPP-14 25/09/201420
Stacked configuration for high voltages
EP
C20
12
U 1
EP
C2
012U 2
EP
C20
12
U 3
EP
C20
12
U 4
V 1500
V 2 P U L S E (0 3 10n 50n 50n 50n 0 1 )
R 12
500K
D 1
m se1p j
D 2
m se1p j
D 3
m se1p j
D 4B ZG 03C 180
D 5B ZG 03C 180
D 6B ZG 03C 180
D 7B ZG 03C 180
R 17
500K
R 20
500K
R 21
500K
R 9
10K
R 10
10K
R 11
10K
R 13
1G
.tra n 0 200n 0
D etecto r
0402 10k resistors0603 500k resistorsEP C2012600V diode M icroSM PZener DO -219AB (SM F)
10 m m x 15 m m10 m m x 15 m m
First Pass Estimating Size of EPC2012 Circuit
• Used only commercial components• Did not do real layout• Size is large but optimization possible
TWEPP-14 25/09/2014
Conclusions
• High Voltage distribution via HV switches and DCS control is being investigated. A test system has been developed to allow real time monitoring of the DUTs during irradiation.
• A number of devices, based upon Si and wider band gap materials, are being investigated. GaN seems promising, will need to be confirmed.
• The control circuitry to enable and disable the HV switches also being investigated.
Thank you!21
TWEPP-14 25/09/2014I
Backup - HV devices example plots – EPC2012
EPC2012 Ids vs. Vgs, Vds max = 200V, Ids compliance= 1mA EPC2012 Igs vs. Vgs, Vds max = 200V
Vgs(V)
Ids(A) Igs(A)
Vgs(V)
DUT#1 , Board A GaN devices rated for up to 200V ( up to 600V would be needed for HV MUX but stacked configuration possible – see later slides)
TWEPP-14 25/09/2014
Backup - HV MUX control scheme
Negative HV multiplier
filter
HV JFETDEPL
V source
• Regardless of the devices used as HV switches, a control circuitry, referenced to a high potential, to enable them is needed
• An investigated option consists of an AC coupled control switch based upon a voltage multiplier (it works with depletion and enhancement mode devices depending on the polarity of the diodes )
-HV
To Detector
II
TWEPP-14 25/09/2014
0
S V E XC
C 11 0 n
C 21 0 n C 1 8
1 0 0 n
R 22 M e g
R 1
5 k
V h ig h3 0 0 V d c
0
V M P Y
* The voltage across R2 is measured vs. amplitude and frequency of Vin ( square wave, 50% duty cycle) and for Vhigh = [0, -300] V* Applying -300 V a slight decrease in abs(Vout) is noticed (some leakage current over the board surface is the likely cause)
‘DABO’ connection
Voltage MPY
‘MOBO’
1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0
-30.0
-25.0
-20.0
-15.0
-10.0
-5.0
0.0Vbias=0V Vbias=-300Vfin=50KHz fin=100kHz fin=50KHz fin=100kHz
Vin(V) Vout(V) Vout(V) Vout(V) Vout(V)1.0 -4.41 -4.41 -3.91 -4.051.5 -7.05 -7.06 -6.37 -6.402.0 -9.76 -9.80 -8.90 -9.102.5 -12.49 -12.56 -11.50 -11.803.0 -15.22 -15.34 -14.00 -14.503.5 -17.97 -18.12 -16.40 -17.204.0 -20.72 -20.90 -18.95 -19.904.5 -23.47 -23.70 -21.50 -22.605.0 -26.23 -26.50 -24.10 -25.40
fin = 50 kHz Vbias =0V
fin = 100 kHz Vbias =0Vfin = 50 kHz Vbias =-300Vfin = 50 kHz Vbias =-300V
V MPY Vout
Vin
Multimeter : Fluke 287Signal generator: Tektronix AFG3252HV PSU: EA-BS315-04B (#2 in series to get 300V)
(HV PSU)(Sign. Gen)
(Meter)
III
Backup - HV MUX control scheme test