To meet the growing demand of higher efficiency power converters, designers are utilizing fast switching wide bandgap (WBG) semiconductors which operate at higher voltages, temperatures, and frequencies. However, just implementing WBG semiconductors are not enough to realize the maximum potential of new converter topologies. Designers must also select the proper passive components such as capacitors to support DC-LINK, snubber, and resonator applications. This webinar will review the wide bandgap semiconductor trend and how it impacts selection of capacitors for high efficiency designs.

1. What’s a Ceramic KC-LINK Capacitor
Doing in My Power Converter?
Webinar
October 22nd, 2018

2. Outline
1. Power Conversion
2. Wide Bandgap Semiconductor Technology
3. KC-LINK: Overview, Performance,
Competition, Ordering
4. Future Developments
5. Summary

3. Power Conversion
Phone charger
Electric vehicles
Power conversion
involves converting
one type of electrical
power to another.
Solar panels

4. 4© KEMET Electronics. All Rights Reserved.
Power Converters
Basic topologies, AC-AC
AC
DC
DC
AC
Input Power Output Power
AC-AC
1

5. 5© KEMET Electronics. All Rights Reserved.
Power Converters
Basic topologies, DC-AC
Input Power Output Power
DC-AC
2
AC
DC

6. 6© KEMET Electronics. All Rights Reserved.
Power Converters
Basic topologies, AC-DC
AC-DC
3
AC
DC
DC
DC
Input Power Output Power

7. Power Converters
Transistors Make it Possible!
Transistors (Electronic Switch)
Traditionally Silicon Based (Si)

8. Power Converters
3 Design Goals
WeightSize Efficiency
Input Output
1 2 3

9. Power Converters
Efficiency Explained
Input Power Output Power
100kW 100kW
Input Power Output Power
100kW 90kW
Actual Power Converter
Ideal Power Converter
Efficiency=100%
Efficiency=90%
𝐸𝑓𝑓𝑖𝑐𝑖𝑒𝑛𝑐𝑦 =
𝑂𝑢𝑡𝑝𝑢𝑡 𝑃𝑜𝑤𝑒𝑟
𝐼𝑛𝑝𝑢𝑡 𝑃𝑜𝑤𝑒𝑟
x 100%

10. Power Converters
Solar Energy Electric Vehicles Data Centers
90% to 90.5% (+0.5%) = BIG SAVINGS
Every 0.5% Matters!

11. 12© KEMET Electronics. All Rights Reserved.
Power Converters
Improving Size, Weight, and Efficiency
Increase Allowable
Transistor
Temperature
Increase
Frequency
Increase
Voltage
No bulky
cooling Smaller passive
components
Lower losses
Lower
losses
Reduced
Weight
Smaller
Size
Improved
Efficiency
1 2 3

12. Power Converters
Limitations with Si Based Power Converters
Limited to lower
temperatures
Bulky cooling
Limited to lower
frequencies
Bulky passive
components
Limited to lower
voltages
Increased losses,
Larger Transistors
Limitation Design Impact
What about Wide Bandgap?

13. Wide Bandgap (WBG) Semiconductors
Density of StatesElectronEnergy
Non-Conductive band
Semiconductor Material
Bandgap
Energy (eV)
Germanium (Ge) 0.7
Silicon (Si) 1.1
Silicon Carbide (SiC) 3.3
Gallium Nitride (GaN) 3.4
WBG
ConductorsInsulators Semiconductors
10-20 10810410010-410-810-1210-16
Conductivity (S/cm)

14. Frequency (Hz)
Power(W)
100 1k 10k 100k 1M 10M 100M 1G 10G 100G
10
100
1k
10k
100k
1M
10M
100M The BIG 3 for WBG
-Higher Voltages
-Higher Frequencies
-Higher Temperatures
Si
SiC
Si
Power Converter
GaN
Wide Bandgap (WBG) Semiconductors

15. Wide Bandgap Based Power Converters
Smaller (Higher Power
Densities)
Less Cooling
More EfficientPower
Conversion
Si Based
WBG Based on GaN
or SiC
DC to DC 85% 95%
AC to DC 85% 90%
DC to AC 96% 99%
Source: Mouser Electronics, L. Culberson, 2016
Typical Si
50kW inverter
WBG SiC
50kW inverter

16. 17© KEMET Electronics. All Rights Reserved.
Wide Bandgap Trend
Impact on Capacitors
Snubber DC Link Resonant
Key Capacitor Applications

17. 18© KEMET Electronics. All Rights Reserved.
0.00
0.01
0.10
1.00
10.00
10 100 1,000 10,000
Capacitance(uF)
Frequency kHz
DC-LINK Capacitance vs Switching Frequency and Voltage
10kW Power Converter
400V 650V 1000V
Wide Bandgap Trend
Impact on Capacitors
* Source: Prof. R. Kennel, Technical University Munich, Germany
Higher Voltage = Lower Capacitance
With WBG
adoption,
Ceramic Caps
play a key role
supporting
semiconductors for
improving
efficiency in
power conversion.

18. Wide Bandgap Trend
Impact on Capacitors
Capacitor RequirementThe BIG 3 for WBG
Smaller, low ESR, low ESL low loss
capacitors with high current handling
capability
Higher Switching Frequencies
20kHz → 100kHz → 100’s MHz
Higher Operation Voltages
400V → 900V →1200V→1700V
Reliable performance at higher voltages
High Junction Temperatures
105oC → 125oC → 200oC+
Reliable performance at elevated
temperatures ≥ 125oC with robust mechanical
performance
Packaging close to the hot semiconductor to:
• Lower ESL
• Minimize cooling costs

19. KC-LINK
• AEC-Q200 automotive qualified
• Very high ripple current capability
• Extremely low ESR
• Extremely low ESL
• Operating temperature range of −55°C to +150°C
• High frequency operation (>10 MHz)
• No capacitance shift with voltage
• No piezoelectric noise
• High thermal stability
• RoHS Pb-free
• Wide bandgap (WBG), silicon carbide (SiC) and gallium
nitride (GaN) systems
• EV/HEV (drive systems, charging)
• Wireless charging
• Photovoltaic systems
• Power converters
• Inverters
• LLC resonant converters
• DC-Link
• Snubber
Features and Benefits Applications

20. Competition
KEMET KC-LINK TDK CeraLink

21. Tale of the Tape
KEMET KC-LINK TDK CeraLink
220nF Capacitance ~600nF
CaZrO3 Dielectric Cu PLZT
Yes Pb-Free No
Yes RoHS
Yes, only by
exemption
150oC Operating Temp 150oC
< 0.10% DF (%) @1kHz < 2.0%
<4mΩ
Typical ESR
@100kHz
~65mΩ
17.1 Arms
Ripple Current
@100kHz, 105oC
9.7 Arms
~1nH Typical ESL ~2.5nH
No, not required Lead Frame Yes, required
>250
Average MOR
(MPa)
<125

22. 26© KEMET Electronics. All Rights Reserved.
KC-LINK vs TDK CeraLink
Capacitance Stability
* Source: TDK CeraLink Datasheet
KEMET KC-LINK TDK CeraLink
KEMET’S KC-LINK remains ultra stable
over voltage and temperature!

23. 27© KEMET Electronics. All Rights Reserved.
0
5
10
15
20
25
30
35
0 5 10 15 20
TemperatureRise(°C)
Ripple Current (ARMS)
Frequency (100kHz)
KC-Link
CeraLink
KC-LINK vs TDK CeraLink
Impedance, ESR, and Ripple Current
1.0E-04
1.0E-03
1.0E-02
1.0E-01
1.0E+00
1.0E+01
1.0E+02
10 100 1,000 10,000 100,000
Impedance&ESR(Ω)
Frequency (kHz)
KC-Link Impedance
KC-Link ESR
CeraLink Impedance
CeraLink ESR
KEMET’S KC-LINK ESR is lower, providing excellent ripple current handling.
KC-LINK’s temperature rise remains very low (20°C) at higher ripple currents.

24. 28© KEMET Electronics. All Rights Reserved.
KC-LINK vs TDK CeraLink
Accelerated Life Testing
0%
10%
20%
30%
40%
50%
60%
70%
80%
90%
CummulativeFailures(%)
Time (hours)
KC-LINK
CeraLink
0 250 500 750 1000
Accelerated Life Testing @600Vdc 200oC
KEMET’S KC-LINK had no
failures during the entire
test!

25. KC-LINK: How to Order
Commercial & Auto grade available

26. KC-LINK Under Development Offering
Available to order now:
CKC33C224KCGACTU
Rest of the waterfall:
UD

27. KC-LINK with KONNEKT Technology
Under Development
Voltage KC-LINK 150°C
Case size 3640
Chips 4
500V 0.88uF
650V 0.60uF
1000V 220nF
1200V 190nF
1700V 88nF
Uses innovative
Transient Liquid Phase
Sintering –TLPS–
technology to bond
component
terminations together
Cross section of KONNEKT ceramic capacitor
Standard
mounting
Low-loss
mounting

28. Summary
• Wide Band Gap – Remember the BIG 3!
• Higher Voltages
• Higher Frequencies
• Higher Temperatures
• KEMET KC-LINK
• Extremely low equivalent series resistance (ESR)
• Extremely low equivalent series inductance (ESL)
• Very high ripple current capability
• Ideal solution for snubber, DC-LINK and resonant applications
Snubber DC Link Resonant

29. Thank you!
Ana Ogui Magaña
Technical Product Specialist - Ceramic Business Unit
KEMET Electronics
Office Phone: +1-864-963-4580
anamagana@kemet.com