Please read the Important notice and the Safety precautions and the Warnings
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UG-2020-31
11 kW bi-directional CLLC DC-DC converter with
1200 V and 1700 V CoolSiC™ MOSFETs
About this document
Scope and purpose
This document introduces a complete Infineon Technologies AG system solution for an 11 kW bi-directional DCDC converter. The REF-DAB11KIZSICSYS board is a DC-DC stage with a wide range output using two inductors
and two capacitors (CLLC) resonant network with bi-directional capability.This converter can operate under
high power conversion efficiency, as the symmetric CLLC resonant network has zero-voltage switching
capability for primary power switches and synchronous-rectification commutation capability for secondry-side
output rectifiers. The converter could change the power flow direction, and its maximum power conversion
efficiency was around 98% during the operation.
This document shows the board using 1200 V CoolSiC™ MOSFETs in TO247-4 package and EiceDRIVER™ 1ED
compact gate driver ICs, which leverage the advantages of SiC technology including improved efficiency, space
and weight savings, part count reduction, and enhanced system reliability.
Intended audience
This document is intended for engineers who want to use 1200 V and 1700 V CoolSiC™ MOSFETs with
EiceDRIVER™ driver ICs for bi-directional resonant topology applications such as EV-charger wall box, energy
storage systems to achieve reliable main-circuit design and increased power density.
Reference board/kit
Product(s) embedded in a PCB, with focus on specific applications and defined use cases that can include
software. PCB and auxiliary circuits are optimized for the requirements of the target application.
Note: Boards do not necessarily meet safety, EMI, quality standards (for example UL, CE) requirements.
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Important notice
Important notice
“Evaluation Boards and Reference Boards” shall mean products embedded on a printed circuit board
(PCB) for demonstration and/or evaluation purposes, which include, without limitation, demonstration,
reference and evaluation boards, kits and design (collectively referred to as “Reference Board”).
Environmental conditions have been considered in the design of the Evaluation Boards and Reference
Boards provided by Infineon Technologies. The design of the Evaluation Boards and Reference Boards
has been tested by Infineon Technologies only as described in this document. The design is not qualified
in terms of safety requirements, manufacturing and operation over the entire operating temperature
range or lifetime.
The Evaluation Boards and Reference Boards provided by Infineon Technologies are subject to functional
testing only under typical load conditions. Evaluation Boards and Reference Boards are not subject to the
same procedures as regular products regarding returned material analysis (RMA), process change
notification (PCN) and product discontinuation (PD).
Evaluation Boards and Reference Boards are not commercialized products, and are solely intended for
evaluation and testing purposes. In particular, they shall not be used for reliability testing or production.
The Evaluation Boards and Reference Boards may therefore not comply with CE or similar standards
(including but not limited to the EMC Directive 2004/EC/108 and the EMC Act) and may not fulfill other
requirements of the country in which they are operated by the customer. The customer shall ensure that
all Evaluation Boards and Reference Boards will be handled in a way which is compliant with the relevant
requirements and standards of the country in which they are operated.
The Evaluation Boards and Reference Boards as well as the information provided in this document are
addressed only to qualified and skilled technical staff, for laboratory usage, and shall be used and
managed according to the terms and conditions set forth in this document and in other related
documentation supplied with the respective Evaluation Board or Reference Board.
It is the responsibility of the customer’s technical departments to evaluate the suitability of the
Evaluation Boards and Reference Boards for the intended application, and to evaluate the completeness
and correctness of the information provided in this document with respect to such application.
The customer is obliged to ensure that the use of the Evaluation Boards and Reference Boards does not
cause any harm to persons or third party property.
The Evaluation Boards and Reference Boards and any information in this document is provided "as is"
and Infineon Technologies disclaims any warranties, express or implied, including but not limited to
warranties of non-infringement of third party rights and implied warranties of fitness for any purpose, or
for merchantability.
Infineon Technologies shall not be responsible for any damages resulting from the use of the Evaluation
Boards and Reference Boards and/or from any information provided in this document. The customer is
obliged to defend, indemnify and hold Infineon Technologies harmless from and against any claims or
damages arising out of or resulting from any use thereof.
Infineon Technologies reserves the right to modify this document and/or any information provided
herein at any time without further notice.
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Safety precautions
Safety precautions
Note: Please note the following warnings regarding the hazards associated with development systems.
Table 1 Safety precautions
Warning: The DC link potential of this board is up to 1000 VDC. When measuring voltage
waveforms by oscilloscope, high voltage differential probes must be used. Failure to do
so may result in personal injury or death.
Warning: The evaluation or reference board contains DC bus capacitors which take
time to discharge after removal of the main supply. Before working on the drive
system, wait five minutes for capacitors to discharge to safe voltage levels. Failure to
do so may result in personal injury or death. Darkened display LEDs are not an
indication that capacitors have discharged to safe voltage levels.
Warning: The evaluation or reference board is connected to the grid input during
testing. Hence, high-voltage differential probes must be used when measuring voltage
waveforms by oscilloscope. Failure to do so may result in personal injury or death.
Darkened display LEDs are not an indication that capacitors have discharged to safe
voltage levels.
Warning: Remove or disconnect power from the drive before you disconnect or
reconnect wires, or perform maintenance work. Wait five minutes after removing
power to discharge the bus capacitors. Do not attempt to service the drive until the bus
capacitors have discharged to zero. Failure to do so may result in personal injury or
death.
Caution: The heat sink and device surfaces of the evaluation or reference board may
become hot during testing. Hence, necessary precautions are required while handling
the board. Failure to comply may cause injury.
Caution: Only personnel familiar with the drive, power electronics and associated
machinery should plan, install, commission and subsequently service the system.
Failure to comply may result in personal injury and/or equipment damage.
Caution: The evaluation or reference board contains parts and assemblies sensitive to
electrostatic discharge (ESD). Electrostatic control precautions are required when
installing, testing, servicing or repairing the assembly. Component damage may result
if ESD control procedures are not followed. If you are not familiar with electrostatic
control procedures, refer to the applicable ESD protection handbooks and guidelines.
Caution: A drive that is incorrectly applied or installed can lead to component damage
or reduction in product lifetime. Wiring or application errors such as undersizing the
motor, supplying an incorrect or inadequate AC supply, or excessive ambient
temperatures may result in system malfunction.
Caution: The evaluation or reference board is shipped with packing materials that
need to be removed prior to installation. Failure to remove all packing materials that
are unnecessary for system installation may result in overheating or abnormal
operating conditions.
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Table of contents
Table of contents
Contents
About this document ....................................................................................................................... 1
Important notice ............................................................................................................................ 2
Safety precautions .......................................................................................................................... 3
Table of contents ............................................................................................................................ 4
1 The board at a glance .............................................................................................................. 5
1.1 Delivery content ...................................................................................................................................... 6
1.2 Block diagram .......................................................................................................................................... 6
1.3 Main features ........................................................................................................................................... 8
1.4 Board parameters and technical data .................................................................................................... 8
2 System and functional description ........................................................................................... 9
2.1 Commissioning ........................................................................................................................................ 9
2.2 Description of the functional blocks ....................................................................................................... 9
2.2.1 Description of the functional blocks ............................................................................................... 10
2.2.2 Special operation modes ................................................................................................................. 15
2.3 Auxiliary power boards ......................................................................................................................... 17
2.3.1 The technical specification of auxiliary power boards ................................................................... 17
2.3.2 Auxiliary power board description .................................................................................................. 17
2.3.3 1700 V CoolSiC™ MOSFET overview ................................................................................................ 18
2.4 User interface ........................................................................................................................................ 19
3 System design....................................................................................................................... 22
3.1 Schematics ............................................................................................................................................ 22
3.2 Layout .................................................................................................................................................... 26
3.3 Bill of material ....................................................................................................................................... 30
4 References and appendices .................................................................................................... 35
4.1 Abbreviations and definitions ............................................................................................................... 35
4.2 References ............................................................................................................................................. 35
4.3 Additional information .......................................................................................................................... 35
Revision history ............................................................................................................................. 36
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The board at a glance
E-mobility is well on its way to revolutionizing private and public transportation, reducing air pollution and
making the earth a better place to live. Energy storage systems can also help save energy consumption by
maximizing the allocation of energy.
Infineon is proud to be a key player in this green megatrend. Being a one-stop shop for high-quality components
and solutions, the target of the REF-DAB11KIZSICSYS board is to build up a solution for bi-directional DC-DC
converters, which will enable customers to implement unique bi-directional charger designs in a very short time.
This featured 11 kW CLLC resonant DC-DC converter with bi-directional power flow capability and soft-switching
characteristics is the ideal choice for on- & off-board chargers and energy storage systems (ESS). This reference
design provides a complete and fully characterized hardware and firmware solution, and user-friendly graphical
user interface (GUI). It ensures that CoolSiC™ MOSFETs integrate with Infineon driver IC, XMC controller, flyback
controller, voltage regulator MOSFETs, current sensor, Cypress memory, and security & safty chip. It is the perfect
way to improve cost-effective power density with high reliability, and easy usage up to the next level!
In UG-2020-31, Figure 1 shows the placement of the different components on the 11 kW bi-directional DC-DC
converter. The outer dimensions of the board, enclosed in the case, are 33.1 mm x 13.4 mm x 6 mm, which results
in a power density in the range of 4.1 W/cm³ (5.5 W/g).
Auxiliary Power Board
Auxiliary Power Board
1200 V SiC MOSFETs- IMZ120R030M1H
Controller Board
1200 V SiC MOSFETs- IMZ120R030M1H
Driver ICs-1EDC20I12AH
Driver ICs-1EDC20I12AH
Current Sensor- TLI4971
Resonant capacitor
Resonant Inductor
Resonant InductorResonant capacitor
Transformer
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The board at a glance
Figure 1 Placement of the different sections in the 11 kW bi-directional CLLC DC-DC converter with
Infineon CoolSiC™ MOSFETs.
1.1 Delivery content
The 11 kW bi-directional board is a CLLC DC-DC converter developed with Infineon power semiconductors as
well as Infineon drivers, current sensor, controllers, communication chip, security chip and memory chip. The
combination of these devices can provide customers with an optimized system solution. The Infineon devices
used in the implementation of the 11 kW bi-directional board include:
Main power board
1200 V CoolSiC
TM
MOSFETs discretes - IMZ120R030M1H
1200VSingle channel IGBT gate driver IC in wide body package -1EDC20I12AH
XENSIV™ - high-precision coreless current sensors for industrial applications- TLI4971
Auxilary power board
1700 V CoolSiC™ MOSFET discretes- IMBF170R1K0M1
PWM-QR (quasi resonant) flyback control ICs- ICE5QSAG
Controller board
32-bit XMC4000 industrial microcontroller ARM® Cortex®-M4 family- XMC4400-F100k512 BA
High speed CAN transceiver generation-TLE9251VSJ
OPTIGA™ TRUST M -SLS32AIA
Low voltage drop linear voltage regulators - IFX25001TFV33
256-Kbit (32K × 8) serial (SPI) F-RAM: FM25V02A from Cypress
More information concerning these devices is available on the Infineon website.
1.2 Block diagram
The REF-DAB11KIZSICSYS design consists of a CLLC in full-bridge configuration (Figure 2). The CLLC resonant
converter is widely used as a DC transformer to interlink the AC/DC to DC bus, because of its advantages of high
power density and the capacity of bi-directional power transfer. In both forward and reverse modes, the
resonant tank possesses almost the same operational characteristics of the conventional LLC resonant
tank.Thus the ZVS+ZCS soft switching can be achieved both in forward and reverse modes, and the switching
losses can be minimized, thereby improving charger efficiency.
This architecture showed in the block diagram contains three parts, the main power circuit, the auxiliary power
board and the control board.
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The board at a glance
Isolated gate driver
1EDC20I12AH
Isolated current
transformer
Isolated current
transformer
Isolated voltage
sensor
Isolated
voltage sensor
XMC4400 MCU Controller
Aux power
CoolSET+SIC MOS
FAN Wifi Module Cypress FeRAM OPTIGATrust X
NTC
Current sensor
isolated
Aux power
CoolSET+SIC MOS
Current sensor
TLI4971
Isolated gate driver
1EDC20I12AH
GUI
Figure 2 11 kW bi-directional CLLC DC-DC converter (REF-DAB11KIZSICSYS ) – simplified diagram
showing the Infineon semiconductors used in the system
The main power circuit includes 1200 V CoolSiCTM MOSFETs make high efficiency possible.
The auxiliary power supply uses 1700 V CoolSiCTM MOSFETs for an efficient design, as it is as small as a card.
The control is implemented in an XMC4400 Infineon microcontroller, which includes the following features:
ARM® Cortex™-M4, 120MHz, incl. single cycle DSP MAC and floating point unit (FPU)
8-channel DMA + dedicated DMAs for USB and Ethernet
USIC 4ch [Quad SPI, SCI/UART, I²C, I²S, LIN]
Supply voltage range: 3.13 - 3.63V
USB 2.0 full-speed, on-the-go
CPU frequency: 120MHz
Peripherals‘ clock: 120 [MHZ]
eFlash: 512 kB including hardware ECC
80 kB SRAM
10/100 Ethernet MAC (/w IEEE 1588)
2x CAN, 64 MO
Package: PG-LQFP-100
4x ΔΣ demodulator
Temperature range from -40° to 125°
Further details about the digital control implementation and other functionalities of CLLC in the XMC™ 4000
family can be found on the Infineon website.
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The board at a glance
1.3 Main features
A bi-directional full-bridge CLLC resonant converter using a symmetric CLLC-type resonant network
is proposed for a bi-directional power distribution system. This converter can operate under high
power conversion efficiency, as the symmetric LLC resonant network has zero-voltage switching
capability for primary power switches and sychronous rectification capability for secondary- side
rectifiers.
In addition, the proposed topology does not require any snubber circuits to reduce the voltage stress
of the switching devices because the switch voltage of the primary and secondary power stage is
confined by the input and output voltage, respectively. In addition, the power conversion efficiency
of any direction is similar. Intelligent digital-control algorithms are also proposed to regulate output
voltage, control bi-directional power conversions and to achieve synchronous rectification.
1.4 Board parameters and technical data
Table 2 shows the specifications of the board
Table 2 Parameter
Parameter
Symbol
Conditions
Value
Unit
Rated power P V
bus
=750V,
VHV=800V,Ta=250C. I
pri.
=15A
11
KW
Primay side bus voltage
V
bus
-
750
V
Secondary side bus voltage
VHV
-
550-~800
V
Primay side current
I
pri.
V
bus
=750V,
VHV=800V,Ta=250C. I
pri.
=15A
15
A
Secondary side current
I
sec.
VHV=550V,P=11KW,
Ta=250C.
20
A
Switching frequency
fs
-
40~200
Khz
Auxilary power output voltage
V
aux.
P
aux.
=32W
15/20
V
Auxilary power output power
P
aux.
V
aux.
=20V, ,Ta=250C.
32
W
Board net weight
W
Without encloser
2
Kg
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System and functional description
2 System and functional description
2.1 Commissioning
This chapter presents the set-up on how to evaluate the performance and behavior of the 11 kW bi-directional
DC-DC converter using CoolSiC™ MOSFETs.
DC source provides the power to the converter prototype
Secondary side of converter prototype connect with the DC electric load
The host computer controls the start and stop of the prototype and sets the working parameters
through GUI
Observe the corresponding waveforms with an oscilloscope
Figure 3 11 kW bi-directional CLLC DC-DC converter measuring environment
2.2 Description of the functional blocks
The 11 kW bi-directional CLLC DC-DC converter can operate as an isolated buck or as an isolated boost
converter, with the power flowing from the bus side to the isolated HV side or vice versa.
For validation of the buck mode, the suggested set-up includes:
Bus supply capable of 700 V~800 V and at least 11 kW (when testing up to full load)
HV electronic load (500 V to 800 V), in constant current mode, capable of at least 11 kW (when testing up to full
load). Nominal input voltage of the converter is 750 V. The converter works as indicated in Figure 4.
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System and functional description
Bus
HV
36uH 132nF 22uH216nF
20:16,Lm=160uH
Q1
Q2
Q3
Q4
Q5
Q6
Q7
Q8
Figure 4 Buck mode recommended validation set-up
For validation of the boost mode, the suggested set-up is exactly the same as for the buck mode, except for
thing: the output voltage parameter must be changed in the GUI window.
2.2.1 Description of the functional blocks
The output gain function of CLLC topology is generally analyzed by the fundamental wave-analysis method.
Based on this analysis method, the parameters of the key resonant components in the current design are
shown in the Figure 4:
By using this parameter, the resonance parameter Q of the primary and secondary transformers is consistent,
and the natural resonance frequency is 73 kHz. In the design, we chose a switching frequency of the topology in
the range of 40 kHz to 200 KHz.
The structure of CLLC topology on the primary side and the secondary side is the same. On the contrary, the
fundamental wave-analysis method is also valid. The relationship between the output/input gain and the
switching frequency of the circuit is shown in Error! Reference source not found.(reverse energy
transmission):
The current of the primary/secondary resonant cavity and the Vds waveform of the SiC MOSFET in the steady
state can be obtained as follows with the help of PLECS simulation software for verification:
Buck mode (forward-energy transmission), input voltage 800 V, and output voltage 550 V with load 27.5 Ω. At
this time, the CLLC topology switching frequency is 86.2 KHz:
Ilr_pri is the primary side resonant tank current.
Ilr_sec is the secondary side resonant tank current.
VHB is the V
ds
voltage of Q2 (The position of SiC MOSFETs Q1~Q8 can be seen in Figure 4.).
Fsw is the switching frequency.
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System and functional description
Figure 5 Simulation result of CLLC buck mode
Forward-energy transmission, input voltage 750 V, output voltage 750 V, load 51.1 Ohm. The switching
frequency of CLLC topology is 54.0 KHz at this condition, the simulation wavefrom can be seen in Figure 6.
Figure 6 Simulation result of CLLC
Boost mode (forward-energy transmission), input voltage 700 V, output voltage 800 V, load 58.1 Ohm. At this
time, the CLLC topology switching frequency is around 48.2 KHz:
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Figure 7 Simulation result of CLLC boost mode
In the case of no load or light load, the CLLC topology must work in frequency-modulation mode (PFM),
otherwise the power devices in the circuit may work at a very high switching frequency. Due to the existence of
parasitic parameters, the output voltage cannot be reduced to the target value under the circumstances of
continuous wave mode. The topology will work in this mode:
Channel 1 is the controller board ouput pulse-width modulation (PWM) signal.
Channel 2 is the output voltage.
Figure 8 Test result of light load
In the “burst” state, the output voltage waveform is as follows when a sudden load is added:
Channel 3 is the output voltage.