Increased Pulse Rep. Rates for Solid State Thyratron ... Power... · Increased Pulse Rep. Rates for...
Transcript of Increased Pulse Rep. Rates for Solid State Thyratron ... Power... · Increased Pulse Rep. Rates for...
Increased Pulse Rep. Rates for Solid State Thyratron Replacements
John WaldronSilicon Power Corporation280 Great Valley PkwyMalvern, PA 19355
PPPS 2019 Orlando, FL 23-282 June, [email protected]
PPPS 2019 Orlando, FL 23-282 June, [email protected]
Outline
• Introduction to Solidtron’s Enabling Technology– Pulse discharge targeted designs
• Solidtron Performance– Discharge Performance
– Increased Pulse Repetition Rate Strategy/Results
• Solid State Discharge Switch Replacements – Motivation
– Approach
– Experimental results
• Summary
• Questions
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PPPS 2019 Orlando, FL 23-282 June, [email protected]
160,000 cells/cm2
SGTO
GTO
~ 50 cells /cm2
SGTO Advantages:
Cell structure 3000 x denser
Upper transistor >100x improved
• Forward drop greatly reduced
• Three times lower turn-off switching loss
Die sizes from 3x3mm to 15x22mm in 200mm IC foundry providing very high yield, repeatability and uniformity!
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Super-GTO Vs. GTOSGTO is an IC foundry-fabricated GTO mated with Silicon Power’s proprietary low inductance ThinPak package
• Turn-on improved by 2 orders of magnitude
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Solidtron: The Enabling Technology
Traditional thyristor design revisited, capturing IC house capability• Higher cell density improves current uniformity, drastically improving Τ𝑑𝑖
𝑑𝑡 capability• Upper base doping profile improved for higher gain • Metal interconnects improved, increased upper transistor gain and electrode bonding
area
IC Foundry Solidtron Cell
GTO Versus Solidtron, Fundamental Differences
PPPS 2019 Orlando, FL 23-282 June, [email protected]
Solidtron Advantages
• Cell density further enhanced
• Emitter area maximized
• Internal metal interconnect density improved
• Upper transistor gain further improved
• Increased cathode bonding pad area
8 inch starting material and improved manufacturing process further improving yield while driving cost down
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Solidtron Vs. Super-GTOSolidtron follows SGTO strategy, focusing on pulse discharge versus turn-off applications
PPPS 2019 Orlando, FL 23-282 June, [email protected]
1600V Solidtron Product line:• Simple gating schemes (low power, easy isolation)• Unmatched Τ𝑑𝑖
𝑑𝑡 capability (>200kA/ms observed)• Easily implemented in series/parallel configurations
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Solidtron Performance: Hyper-Fast
Capacitor Voltage (Ch2 Max Ref only)
Anode Current 3kA IPK
160ns ½ period
170ns ½ cycle ring down – Yellow = Anode Current, Cyan = Capacitor Voltage
Turn-on delay <90ns
Jitter <500ps
Fall time <40ns
di/dt >200kA/ms
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Solidtron Performance: Hyper-Fast
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550ns ½ pulse width ring down
1ms ½ pulse width ring down
Solid state discharge switch offers:• Rugged yet simple gate trigger• Repeatable fabrication and performance• Bidirectional current flow capability• Very high MTBF, minimizing down time
Ipk 1.8kA
Ipk 1.1kA
Hyper-Fast 1600V Solidtron Discrete products
Available in:• TO-247 • TO-264• Custom SMT packages
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Solidtron: Increased Switching Speed
Punch-through design:• Higher BV for given device thickness• Allows bipolar current conduction• Improves turn-on speed• Reduces commutation time
Lower-base width and doping concentration determines BV
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Solidtron: Increased Switching Speed
One factor contributing to commutation time is stored charge remaining in lower-base• Thinner lower-base results in less stored charge • Thinner lower-base reduces distance required for diffused carrier to reach emitter
Physically narrower lower-base is employed
¼
Can be thinned after processing to reduce Ron
Implementing lower voltage devices improves commutation time
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Post-Fabrication Speed Enhancement
1
10
100
1000
0 20 40 60 80 100 120
t-o
ff (
us)
Temp °C
Commutation Time vs T at 5kAcm-2
Dose 4
Dose 3
Dose 2
Dose 1
As
fab'd
1
10
100
1000
0 20 40 60 80 100 120
t-o
ff (
us)
Temp °C
Commutation Time vs T at 10kAcm-2
Dose 4
Dose 3
Dose 2
Dose 1
As
fab'd
Reducing Minority Carrier Lifetime:• Increases pulse repetition capability
• Decreases commutation time without the need for complicated gate drive
• Post-fabrication process• Enables 1 design to cover range of applications
• Low-cost, high-volume capable process• Demonstrated an 18x improvement in commutation
time at 110°C and 10kAcm-2
• Favorable tradeoff for Ron and ILeakage
12.5µs → 80kHz
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Post-Fabrication Speed Enhancement
1.0E-02
1.0E-01
1.0E+00
1.0E+01
1.0E+02
0 1 2 3 4 5
Lea
kage
Cu
rren
t (µ
A)
Dose #
Leakage Current at 1500V
as fab'd 85°C as fab'd 110°C
1 85°C 2 85°C
1 110°C 2 110°C
3 85°C 3 110°C
4 85°C 4 110°C
0
0.5
1
1.5
2
2.5
3
3.5
4
4.5
5
200 400 600 800 1000 1200
R-o
n (
mO
hm
)
J (Acm-2)
Differential Resistance at 110°C Dose 4 Dose 3
Dose 2 Dose 1
As fab'd
Reducing Minority Carrier Lifetime Tradeoffs:• Lower base gain is reduced, ↑ RON
• Lower τ increases generation current (↑leakage)• However, small ↑RON (<2x) for almost 20x
improvement in pulse rep rate
0 1 2 3 4 5
Rel
ati
ve L
ifet
ime
(A.I
.)
Dose #
Relative Lifetime Vs Dose
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Solid State Discharge SwitchesMotivation
• Compliance with RoHS • Eliminate conditioning requirements• Eliminate requisite heaters• Simplify gating
• Built in gating requires TTL/Optical trigger and DC power supply• Improve efficiency
• In both energy transfer and off-state conditions• Improve turn-on delay and jitter• Increase usable lifetime
• No terminal erosion• Eliminate liquid cooling requirements• Increase mechanical installation flexibility• Improved performance over IGBT/SCR-based solid state switch replacements
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Hyper-Fast Solid State Thyratron Replacement40kV SSTR-1 (Twin Stack)• Initial TO-247 version demonstrated 365k pulses
o 3kA, 300ns square wave
• Similar 20kV and 60kV derivatives planned to complete the product offering
• Negligible power dissipation in off-state (snubber resistors much higher in value)
• TO-264 version offers up to 30x increase in action
TO-247: SP245-03TO-264: SP275-02
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Solid State Thyratron Replacement
40kV SSTR-1 (Twin Stack) Vs. e2v CX2282
Hyper-Fast 1600V Solidtron
• Τ𝑑𝑖𝑑𝑡 capability is >200kA/mSec
• Fiber Optically Triggered
• Small size - 9” Tall, 3.75” Base diameter
• Voltage capability of 40kV
• Yellow - 4.7kA Peak Current w/average Τ𝑑𝑖
𝑑𝑡 of ~60kA/mSec(Circuit Limited)
• Magenta - 36kV Discharge
Anode Current
Capacitor Voltage (Ch2 Max Ref only)
50nSec rise timePeak I >4kARep Rate = 100PPS
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Summary
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• RoHS compliance
• Unparalleled solid state Τ𝑑𝑖𝑑𝑡 capabilities
– Hyper-fast demonstrated 200kA/ms
• 𝑓(𝑖 𝑡 , 𝜏) capability, determined by experimental and/or sim data exceeds most if not all commercially available gas or solid state thyratrons available
• Designed with modular, scalable sub-assemblies
– Enables fitment for most thyratron or ignitron applications