Page 8 - PEN eBook NOVEMBER 2022

COVER STORY – DESIGN COVER STORY – DESIGN

CONCLUSION
The past few years have seen very rapid development Nov. 15–18, 2022: Join us at electronica in Munich in Hall C3,
in the components and applications of smart charging Booth 502, or digitally
technologies. While a great deal of focus has been on
standardizing wired charging toward USB-C to enable As a leader in IoT and power systems, we have the
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universal connectors, there is also a growing trend technologies, innovative drive, collaborative spirit, and agility
to make charging more pervasive and convenient for to drive decarbonization and digitalization. Various hands-on
various user groups — this is the prime mover for demos will provide impressive proof of the many ways we have
wireless charging. teamed up with customers and partners to accelerate the
delivery of concrete, value-adding answers to today’s green and
Our wireless charging solutions with Infineon’s digital transformation challenges.
OPTIGA™ Trust Charge Authentication offer a
compelling bill-of-materials value proposition to OEMs Also on stage will be our revolutionary and extensive wide-
looking to develop Qi v1.3.2–compliant transmitters. bandgap portfolio. Spanning GaN and SiC technologies, it brings
The key features, such as adaptive FOD, support for an unmatched quality to efficiency-critical applications that feed
proprietary protocols, DC/DC controller integration, and into the decarbonization and digitalization trends.
software libraries, make our platform unique and well-
positioned to cater to proprietary as well as emerging We look forward to meeting with you face to face and
Qi standards for inductive wireless charging. reconnecting after such a long gap. Visit us in Hall C3 at Booth
502 for a holistic and unique Infineon-brand experience.
Please scan the QR code and visit
our wireless charging ICs website We also invite you to visit our digital
to explore how Infineon’s WLC platform, the perfect hub to dive
programmable solutions are able deeper into the various technologies
to offer the required flexibility to we will be showcasing at electronica
Wireless charging scale to higher power levels while 2022 — both during and after the
Figure 1: In-cabin wireless charging solution with WLC1515 (bottom) vs. a standard discrete solution (top) 4 solutions remaining Qi-compatible. event. Scan the QR code to visit our
website and find out more. electronica

Foreign object detection To prevent erroneous disconnects and improve user
WLC1515 transmitter controller also supports enhanced experience, WLC1515 uses an adaptive algorithm that
FOD based on Q factor, resonance frequency, power loss, distinguishes between real P loss FOD versus P loss arising
and overtemperature (if a thermistor is used) methods. from poorly coupled PRx. The FOD coefficients and the
P loss thresholds are fully configurable to adapt to the
The Q factor and resonance frequency measurements system design. For More Information
are used for FOD before the power delivery phase. The
PRx reports the Q factor and resonance-frequency
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reference values calibrated with a Qi-defined reference ▶ Sánchez et al. (Sept. 7, 2021). “Technical Supporting Study to Assess the status of Wireless Charging.”
coil. The PTx compares the reported values with its European Commission, Fraunhofer IZM.
measured values in situ to determine the presence of ▶ Wireless Power Consortium Qi Specification
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a foreign object. A scaling factor is used to convert the
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PRx-reported Q factor and resonance-frequency values ▶ Infineon Technologies. (May 25, 2022). “WLC1515 15-W MP-A11 wireless power transmitter reference
to those equivalent to the reference transmitter coil board (REF_WLC_TX15W_C1) test report.” User Guide, 002-35395 Rev. A. link
and to accommodate measurement variations. ▶ Smith, K. (May 12, 2022). “Hardware design guidelines for WLC transmitter.” Application Note, AN235387.
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The power loss method is mainly used during the ▶ Ramanujam, C. (May 2, 2022). “Provisioning OPTIGA™ Trust Charge for WLC transmitters.” Application
power transfer phase. The power loss FOD uses the Note, AN235196.
PTx power measured at the buck output, which is ▶ Ramanujam, C. (May 3, 2022). “Foreign object detection tuning guide for wireless power transmitters.”
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fed to the inverter bridge. This PTx power is further Application Note, AN234970.
adjusted by tuning FOD coefficients to account 7
for inverter losses and friendly metal losses. After ▶ Infineon Technologies, “Enabling DC input power-based wireless charging operation on the REF_WLC_
computing the calibrated PTx power, the result is TX15W_C1 reference board.” Knowledge Base Article, KBA235366.
compared against the latest PRx reported power value. ▶ European Commission. (Sept. 23, 2021). “Proposal for a Directive amending Directive 2014/53/EU on the
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An FOD event is logged if the difference between the harmonization of the laws of the Member States relating to the making available on the market of radio
calibrated PTx power and PRx power exceeds the P loss Figure 2: Key components of the WLC1515 solution demo equipment.” Online Document.
board response of attenuation, input impedance, and output
threshold. impedance

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