Gan Systems GSWP100W-EVBPA User manual

GSWP100W-EVBPA
GaN E-HEMT Wireless Power Transfer Evaluation Board
User’s Guide
_____________________________________________________________________________________________________________________
GSWP100W-EVBPA Rev 180529 © 2018 GaN Systems Inc. www.gansystems.com 1
Please refer to the Evaluation Board/Kit Important Notice on page 26
GSWP100W-EVBPA
100W GaN E-HEMT Wireless Power Transfer
Evaluation Board, Optimized for Class EF2
Amplifiers
User’s Guide
Visit www.gansystems.com for the latest version of this user’s guide.

GSWP100W-EVBPA
GaN E-HEMT Wireless Power Transfer Evaluation Board
User’s Guide
_____________________________________________________________________________________________________________________
GSWP100W-EVBPA Rev 180529 © 2018 GaN Systems Inc. www.gansystems.com 2
Please refer to the Evaluation Board/Kit Important Notice on page 26
DANGER!
Electrical Shock Hazard -Hazardous high voltage may be present on the
board during the test and even brief contact during operation may result in
severe injury or death. Follow all locally approved safety procedures when
working around high voltage.
Never leave the board operating unattended. After it is de-energized,
always wait until all capacitors are discharged before touching the board.
This board should be handled by qualified personnel ONLY.
PCB surface and devices can become hot. Contact may cause burns. Do not
touch!
CAUTION
This product contains parts that are susceptible to damage by electrostatic
discharge (ESD) or exposure to voltages in excess of the specified voltage.
Always follow ESD prevention procedures when handling the product.
Avoid applying excessive voltages to the power supply terminals or signal
inputs or outputs, always connected to the load during the test on-going.

GSWP100W-EVBPA
GaN E-HEMT Wireless Power Transfer Evaluation Board
User’s Guide
_____________________________________________________________________________________________________________________
GSWP100W-EVBPA Rev 180529 © 2018 GaN Systems Inc. www.gansystems.com 3
Please refer to the Evaluation Board/Kit Important Notice on page 26
Introduction to Magnetic Resonant Wireless Power Transfer
Recent technological advances in power semiconductors are enabling Wireless Power Transfer
(WPT) as a technically and commercially viable option for charging and powering equipment
across a wide range of markets, applications, and power levels.
Inductive charging has been in use for a number of years, however, it’s burdened with limitations
that restrict it to low power applications with tightly controlled alignment between the transmitter
and receiver.
A more advantageous approach, magnetic resonant charging, addresses these shortcomings by
using a high frequency oscillating magnetic field to transfer energy. The benefits that magnetic
resonant charging offers include variable spacing between the transmitter and receiver, the ability
to charge through materials such as a desk or an enclosure, one-to-many charging, ease of
installation, suitability for high power levels, and fast charging. Table 1 provides a comparison
between inductive charging and magnetic resonant charging.
GaN E-HEMTS are a key enabler of magnetic resonant charging because their extremely fast
switching speeds, on the order of a few nanoseconds, result in very low switching losses. This
allows them to operate efficiently at very high frequencies, such as the 6.78MHz that is commonly
used for magnetic resonant charging.
Table 1 A comparison of Inductive charging and Magnetic Resonant charging
Charging technology
Inductive
Magnetic Resonant
Frequency range
80-300kHz
6.78MHz
Max transfer range
5mm
50mm
Multi-device
No
Yes, at different power levels
Spatial Freedom
Low
High
Power Range
Low & limited
30W max
Broad & versatile
50W to 20kW+
Efficiency
Limited to 80%
High: up to 95%
A high-level block diagram of a resonant wireless power transfer system is shown in Figure 1. The
transmit section is composed of a power amplifier, an impedance matching circuit and a transmit
coil. High frequency energy is transferred wirelessly at 6.78MHz to the receive circuit which is
comprised of a receive coil, an impedance matching circuit and a rectifier.
The GSWP100W-EVBPA evaluation board is designed to support and expedite the innovation of
WPT systems by providing the Power Amplifier, the most challenging aspect of the system design.

GSWP100W-EVBPA
GaN E-HEMT Wireless Power Transfer Evaluation Board
User’s Guide
_____________________________________________________________________________________________________________________
GSWP100W-EVBPA Rev 180529 © 2018 GaN Systems Inc. www.gansystems.com 4
Please refer to the Evaluation Board/Kit Important Notice on page 26
Figure 1 - A magnetic resonant wireless power transfer design.
Evaluation board overview
The GSWP100W-EVBPA uses GaN Systems’ GS61008P E-HEMTs in a 6.78MHz class EF2 power
amplifier. The GS61008Ps are used with the integrated high-speed pSemi PE29102 gate driver in a
push-pull configuration. The outputs of the PE29102 are capable of providing switching transition
speeds in the nano-seconds range for hard switching applications.
This User’s Guide includes a circuit description, a quick-start guide and measurement results.
Evaluation Kit Contents and Requirements
Kit Contents
The GSWP100W-EVBPA includes the following hardware for evaluating the GaN E-HEMT 100W
power amplifier.
Table 2 GSWP100W-EVBPA Evaluation Kit Contents
Quantity
Description
1 GaN E-HEMT GS61008P WPT PA evaluation board assembly
1 WPT PA heatplate
1 WPT PA EMC shield
2 2 pins DC cord

GSWP100W-EVBPA
GaN E-HEMT Wireless Power Transfer Evaluation Board
User’s Guide
_____________________________________________________________________________________________________________________
GSWP100W-EVBPA Rev 180529 © 2018 GaN Systems Inc. www.gansystems.com 5
Please refer to the Evaluation Board/Kit Important Notice on page 26
Hardware Requirements
In order to evaluate the performance of the evaluation board, the following equipment is required:
• DC power supply 100V/15A
• TEK scope with current probe TCM0030A
• Fluke 87 multimeter for input current
• 50dB 500W attenuator as load
• Spectrum analyzer
• Power meter
• Thermal meter
Evaluation Board Assembly Overview
The evaluation board (EVB) is assembled with two GS61008P E-HEMT transistors and two PE29102
GaN E-HEMT drivers. Headers are included for monitoring the signal input, signal output, power
connections and detection monitoring signals. Probe points are included for waveform
measurements. Provision has been made for a single, suitable heatsink to be fastened against the
two E-HEMTs, using the two holes in the center of the bottom heatplate.
Figure 2 • Top side of GSWP100W-EVBPA Evaluation Board Assembly

GSWP100W-EVBPA
GaN E-HEMT Wireless Power Transfer Evaluation Board
User’s Guide
_____________________________________________________________________________________________________________________
GSWP100W-EVBPA Rev 180529 © 2018 GaN Systems Inc. www.gansystems.com 6
Please refer to the Evaluation Board/Kit Important Notice on page 26
Figure 3 • Bottom side of GSWP100W-EVBPA Evaluation Board Assembly, showing copper coins
Figure 4 • GSWP100W-EVBPA Evaluation Board heatplate

GSWP100W-EVBPA
GaN E-HEMT Wireless Power Transfer Evaluation Board
User’s Guide
_____________________________________________________________________________________________________________________
GSWP100W-EVBPA Rev 180529 © 2018 GaN Systems Inc. www.gansystems.com 7
Please refer to the Evaluation Board/Kit Important Notice on page 26
Block Diagram
The block diagram of the evaluation board is provided in Figures 5 through 7.
Figure 5 • GSWP100W-EVBPA WPT Push-Pull EVB Block Diagram
Note: The coil in Figure 5 is not included in the EVB.
Figure 6 • GSWP100W-EVBPA WPT Class EF2 PA Block Diagram
Note: The switch devices are GaN Systems’ GS61008P E-HEMTSs

GSWP100W-EVBPA
GaN E-HEMT Wireless Power Transfer Evaluation Board
User’s Guide
_____________________________________________________________________________________________________________________
GSWP100W-EVBPA Rev 180529 © 2018 GaN Systems Inc. www.gansystems.com 8
Please refer to the Evaluation Board/Kit Important Notice on page 26
Figure 7 • GSWP100W-EVBPA WPT driver Block Diagram
Figure 8 • PE29102 Dead-time Waveforms and Duty Cycle Setting
Figure 9 • Dead Time vs Dead Time Resistor

GSWP100W-EVBPA
GaN E-HEMT Wireless Power Transfer Evaluation Board
User’s Guide
_____________________________________________________________________________________________________________________
GSWP100W-EVBPA Rev 180529 © 2018 GaN Systems Inc. www.gansystems.com 9
Please refer to the Evaluation Board/Kit Important Notice on page 26
Circuit Description
The Push-Pull circuit is comprised of two single ended PAs which share a common supply, however;
the impedance matching and EMI filters are separated.
The high-side E-HEMTs are powered by a DC source, referred to as the HV supply. It is connected
through J32. The voltage of this source not exceed 33VDC.
The low-voltage logic circuitry runs off a 3.3VDC voltage regulator, U88, which is powered from a
+5VDC source connected through JP35. The +5VDC rail also feeds two PE29102 drivers U86 and U90,
which are driven independently by U87, a common logic D-type flip/flop. U87 has a frequency
divider configuration, which is driven by a crystal oscillator Y8 at a frequency of 13.56MHz. The
two PE29102 gate drives are capable of 6V operation.
The PA can be configured to operate in a number of different modes, which include
•Push-pull configuration with an EMI filter
•Single ended mode
•Operation without an EMI filter
•Operation with an external oscillator signal input. Users can run multiple PAs together at
the same frequency for high power operation.
Detailed operation procedures and setup for these alternative configurations are provided in the
section titled “quick start guide”.
The PA includes an over-temperature protection circuit. Temperature sensor U9, placed close to the
GS61008P E-HEMTs, monitors their temperature. In an over-temperature condition, the PE29102A
driver will be disabled through U133 and stop driving the E-HEMTs. The design also includes
circuitry to protect against over-current, and load mismatch.
The evaluation board includes an EMI filter, comprised of one low pass filter and one notch filter.
The output of PA can be configured, through jumpers, to operate either with or without an EMI
filter. The detailed jumper and SMA connector configurations are listed in Table 4
For convenience, test points are provided to monitor and measure the electrical signals. A
description of the test points and diagram of their location is provided in Table 5.
The PA also includes a Micro Controller Unit (MCU) monitor interface header, J1. The signals
available through J1 can be used to control the PA system for close loop in the WPT system. A
definition of the signals available on header J1 is provided in Figure 10.

GSWP100W-EVBPA
GaN E-HEMT Wireless Power Transfer Evaluation Board
User’s Guide
_____________________________________________________________________________________________________________________
GSWP100W-EVBPA Rev 180529 © 2018 GaN Systems Inc. www.gansystems.com 10
Please refer to the Evaluation Board/Kit Important Notice on page 26
Figure 10 • MCU interface definition. Signals on J1
The PA connectivity is depicted in Figure 11 and includes the RF input and output, the DC biases
and the MCU monitor interface.
Figure 11 • Circuit Connectivity
Protection Circuit
The PA includes circuitry to protect against input DC overcurrent, device over temperature, output
RF overvoltage and Voltage Standing Wave Ratio (VSWR) protection. The protection signals are
combined by U133, a 3 inputs OR gate logic chip, and will shut the driver down under a fault
condition.
Input DC overcurrent protection (OCP): U91 is the DC current sensor chip, which can handle a
maximum of 10A. The output of the current sensor ship is a current sense signal that goes thru
buffer OP U122 and is compared to a reference voltage. The reference voltage is set with R101 and
• Monitor signals on J1.
• Pin1: PA GND
• Pin2: 5V Input
• Pin3: output voltage detection
• Pin4: PA HV DC current
• Pin5: 3.3V DC
• Pin6: over voltage and current
• Pin7: output power detection
• Pin8: Temperature sensor voltage
• Pin9: PA HV DC input
• Pin10: Fan control enable

GSWP100W-EVBPA
GaN E-HEMT Wireless Power Transfer Evaluation Board
User’s Guide
_____________________________________________________________________________________________________________________
GSWP100W-EVBPA Rev 180529 © 2018 GaN Systems Inc. www.gansystems.com 11
Please refer to the Evaluation Board/Kit Important Notice on page 26
R177. Upon an over current event, a signal is generated to signal OCP_TRIG.
Overvoltage protection (OVP): The design includes overvoltage protection circuitry for both the
high side and the low side. The high side voltage sensor is comprised of C276, C277, and two
Schottky diodes; D52 and D44. C276/C277 form a voltage divider, the ratio of which can be
changed. Two diodes rectify the RF signal to DC thru C278/C22 and R111 and the resulting voltage
represents the high side output. The low side circuit is similar. It’s comprised of C270, C280, and
two diode D50, D53. These two voltage detection signals go to a two-channel comparator U68 and
are combined with OR gate U70 into one overvoltage trigger, OVP_TRIG.
The OVP and OCP go into a hard combine circuit D45, which a dual diode in one. To generate an
overcurrent / overvoltage protection trigger signal.
Standing Wave Ratio (SWR) detection: two of coupler, T2, T83, comprise of the board band
bidirectional coupler. The reflection signal goes thru D75, C722, C721, it turns into DC signal which
goes thru the buffer OP U132 into comparator U130, of which the reference voltage is set by the
R936/R937, the trigger point can be set by the reference voltage, which is refer the SWR. The
direction of the coupler is around 15dB at 6.78MHz.
Figure 12 • Connectivity locations
Thermal Management
Thermal management of the GaN E-HEMTs in this RF power system is a critical aspect of the
design. Maintaining low device temperatures through proper thermal management enhances the
system reliability and extends the range of operating temperature.
The GS61008P are bottom-side cooled devices that use GaNPX® packaging, designed for optimal

GSWP100W-EVBPA
GaN E-HEMT Wireless Power Transfer Evaluation Board
User’s Guide
_____________________________________________________________________________________________________________________
GSWP100W-EVBPA Rev 180529 © 2018 GaN Systems Inc. www.gansystems.com 12
Please refer to the Evaluation Board/Kit Important Notice on page 26
thermal performance. For effective thermal management, a hole is cut out of the PCB to permit
access to the copper coins. The two GS61008Ps’ bottom side thermal pads are soldered directly onto
the copper coins on the bottom side of the PCB and the Gate, Drain and Source signals are routed on
the top side of the PCB. This set up provides an ultra-low thermal impedance from the die to the
copper coins.
Figure 13 • Copper coins soldered beneath PCB and devices top PCB
Figure 14 • Aluminum heatplate with housing for two copper coins.
Heatplate
PCB back side

GSWP100W-EVBPA
GaN E-HEMT Wireless Power Transfer Evaluation Board
User’s Guide
_____________________________________________________________________________________________________________________
GSWP100W-EVBPA Rev 180529 © 2018 GaN Systems Inc. www.gansystems.com 13
Please refer to the Evaluation Board/Kit Important Notice on page 26
Quick Start Guide
The GSWP100W-EVBPA EVB is designed to as a platform for evaluating the GS61008P E-HEMTs in a
Push-Pull Class EF2 PA for WPT. This chapter will guide the user through the evaluation board
overview, PA operation, bench setup and test results.
Evaluation Board Overview
Kit Contents
The GSWP100W-EVBPA evaluation kit contains:
• Power Amplifier evaluation board assembly
• PA heatplate
• PA EMC shield
• 2 pins DC cord
Evaluation board specifications
Table 3: EVB specifications:
PARAMETER
SPECS
Input Voltage range
33V
DC
max
Tx output power
100W
Tx efficiency (peak)
88%
Topology/Class
EF2
Frequency
6.78 MHz
Switching type
Push/Pull
GaN Systems part number
GS61008P
Number of GS devices
2
Optimized RL (load)
30Ω
Constant current mode
optional
The maximum operating specifications of the evaluation board are as follows:
• Maximum HV supply input operating voltage of 33VDC
• Maximum LV supply input operating voltage of 7VDC
• Frequency of operation of 6.78MHz.
• Maximum output power of 100W *

GSWP100W-EVBPA
GaN E-HEMT Wireless Power Transfer Evaluation Board
User’s Guide
_____________________________________________________________________________________________________________________
GSWP100W-EVBPA Rev 180529 © 2018 GaN Systems Inc. www.gansystems.com 14
Please refer to the Evaluation Board/Kit Important Notice on page 26
Note: * The maximum output power depends on the input voltage, as shown in Figures 21 and
24.
Configurations
The PA can be configured into three different operating options: voltage mode, current mode, and single
ended. Table 4 describes how to configure the board using the jumpers provided.
Table 4: Configuration options
Jumper
Option
Jumper on/off
JP51
Internal oscillator (default)
JP51 on / JP52 off
JP52
External oscillator
JP51 off / JP52 on
Voltage mode (without EMI filter)
Voltage mode
JP42 off / JP44 off
Current mode (with EMI filter)
Current mode
JP43 off / JP44 on
Voltage mode output
RF output
JP56
Current mode output
RF output
JP57

GSWP100W-EVBPA
GaN E-HEMT Wireless Power Transfer Evaluation Board
User’s Guide
_____________________________________________________________________________________________________________________
GSWP100W-EVBPA Rev 180529 © 2018 GaN Systems Inc. www.gansystems.com 15
Please refer to the Evaluation Board/Kit Important Notice on page 26
Test points
To monitor the performance of PA, test points are provided and as described in Table 5. All test points
are available on the top side of the board, none are on the bottom side. The test points locations are
silkscreened on the PCB.
Table 5: Test point description
Test point Description
TP197 U90 input (PE29102 driver)
TP76 U6 input (PE29102 driver)
TP8 Q77 Gate voltage
TP81 Q76 Gate voltage
TP189 Q77 Drain voltage
TP82 Q76 Drain voltage
TP176 60V DC current detection
TP194 External oscillator monitor
Evaluation Bench Test Setup
The test bench setup for the GSWP100W-EVBPA EVB is shown in Figure 15. Ensure that the safety
precautions mentioned on page 2 are followed.
Figure 15 • Bench setup
A recommended list equipment is provided below. Equipment with equivalent performance
specifications can be substituted. In all cases, ensure that it is well calibration.
•DC power supply 100V/15A
•TEK scope with current probe TCM0030A

GSWP100W-EVBPA
GaN E-HEMT Wireless Power Transfer Evaluation Board
User’s Guide
_____________________________________________________________________________________________________________________
GSWP100W-EVBPA Rev 180529 © 2018 GaN Systems Inc. www.gansystems.com 16
Please refer to the Evaluation Board/Kit Important Notice on page 26
•Fluke 87 multimeter for input current
•50dB 500W attenuator as load
•Spectrum analyzer: RIGOL DSA 815
•Power meter: GiGa 8542C
•Thermal meter, sensor is located at screw of copper coin
Note: The WPT test setup is normally a non-50Ω system. If the PA is tested under a non-50Ωsystem, the
measurement results may not correlate with 50Ω system due to the mismatch.
Hardware Operation
The following steps provide a guideline for proper hardware operation and configuration.
1) First, set the current limit to 0.3A for the +5VDC supply feeding JP35.
2) Set the current limit to 1A for the HV DC supply feeding JP32 at a voltage of between +10VDC
and +30VDC.
3) Verify that all DC power supplies are turned off.
4) Make sure the load is connected to JP56 or JP57.
5) Verify the Class EF2 waveform via test points TP8, TP81 with JP32 +5VDC.
6) Connect the VDD power supply to JP32. Apply between 4V to +10VDC to JP32. Read the output
power at JP56 or JP57.
7) Turn on the HV supply to the desired value. Do not exceed the absolute maximum voltage of
+33VDC. Keep the JP32 +5VDC on.
8) To power the evaluation board down, reverse the steps above.
Measurement Technique
When measuring the high frequency content switch node, care must be taken to avoid long ground
leads. Measure the switch node by placing the oscilloscope probe tip at JP192 and JP193 (designed for
this purpose) or to the closest ground screws. Refer to Figure 16 for the proper probe technique.

GSWP100W-EVBPA
GaN E-HEMT Wireless Power Transfer Evaluation Board
User’s Guide
_____________________________________________________________________________________________________________________
GSWP100W-EVBPA Rev 180529 © 2018 GaN Systems Inc. www.gansystems.com 17
Please refer to the Evaluation Board/Kit Important Notice on page 26
Figure 16 • Proper oscilloscope probe measurement technique
PA Performance without EMI filter
Power-on Procedure without EMI filter
•An additional heatsink may be required. The PA heatplate is provided with threaded hole
locations that can be used to attach the heatsink to the heatplate with 4-40 screws. To ensure
excellent thermal conduction, apply thermal grease to the PA / heatsink interface before
screwing the units together. Enough thermal grease should be applied so that a small amount
extrudes on all four sides as the screws are tightened. Wipe the assembly clean.
•Make sure jumpers JP43/JP44 are off
•Solder the wires with the SMA connector to JP56.
•Connector the load to JP56
•Plug the 5VDC supply into JP35. Pin 1: positive. Pin 2: negative. Turn the supply on and set the
DC input voltage to 5V
•Plug the HV supply into JP32. Pin 1: positive. Pin 2: negative. Turn the supply on and ramp the
voltage from 0V to 10V.
•Monitor the test point voltage by comparing the power meter measurement to GaN Systems’
test data which is available in Appendix A.
•If the measurements correlate, increase the HV supply to 28VDC.
•IMPORTANT: Ensure the 5VDC supply does not exceed 6V during testing.

GSWP100W-EVBPA
GaN E-HEMT Wireless Power Transfer Evaluation Board
User’s Guide
_____________________________________________________________________________________________________________________
GSWP100W-EVBPA Rev 180529 © 2018 GaN Systems Inc. www.gansystems.com 18
Please refer to the Evaluation Board/Kit Important Notice on page 26
Evaluation Results-without EMI filter
The evaluation results for performance without an EMI filter are captured in Figures 17 through 21.
Figure 17 • Oscilloscope Plot Showing Both GS61008P Gate Node Signals at TP8, TP81
For a Class EF2 power amplifier topology, the optimal efficiency is achieved at a duty cycle of
approximately 35%. At that operating point, the PA can work under very ZVS wide impedance range
with high efficiency. The PA duty cycle is controlled by gate driver PE29102A. For a detailed time-delay
design please refer to Figure 8 and Figure 9. The total resistor value of R955/R965 dominates the dead
time of U86, and the delay time of U90 is controlled by R953/R952. Both two of PE29102A operate as
high side mode, low side of chip is disable, and to reduce inductance thru shortened length of trace
between gate of GS61008P and PE29102A, the pins of low side output of PE29102A are removed in the
layout.
Typical waveforms at the devices Drain node are shown in Figure 17. Channel 1 is shown in yellow and
channel 2 is shown in blue. At 31VDC input voltage, the output power is 100W before the EMI filter.

GSWP100W-EVBPA
GaN E-HEMT Wireless Power Transfer Evaluation Board
User’s Guide
_____________________________________________________________________________________________________________________
GSWP100W-EVBPA Rev 180529 © 2018 GaN Systems Inc. www.gansystems.com 19
Please refer to the Evaluation Board/Kit Important Notice on page 26
Figure 18 • Oscilloscope Plot Showing Both GS61008P Drain Node Signals
The ratio of maximum Drain voltage and input DC voltage is 2.33 which is ideal for a class EF2 amplifier.
This operating condition eliminates voltage stress on the transistors and has low second harmonics. The
output current shown in green, is not a perfect sinewave due to high order harmonics on the output load.
Switch mode Power Amplifiers have a lot of harmonics at the output. One significant advantage of the
Class EF2 topology is that it has a lower 2nd harmonic when compared to other PA topologies. This
advantage results in a Class EF2 PA with much better EMI performance.
Figure 19 shows the spectrum of the PA at 100W output power without an EMI filter. Compared to the
fundamental frequency, the 2nd harmonic is -35dBc, the 3rd harmonic is -20dBc, and the 4th harmonic is -
34dBc. This extremely low 2nd harmonic performance makes it much easier to filter out the PA’s high
order harmonic. This allows designers to meet EMI specifications and regulations without additional cost.
The PA’s output power and efficiency are shown in Figure 20. This PA delivers 93% efficiency at 100W
output power and 27VDC input voltage. This remarkable efficiency performance makes PA the best
candidate of the WPT systems, and particularly advantageous for high power applications such as drone,
autonomous robot and E-bike charging.

GSWP100W-EVBPA
GaN E-HEMT Wireless Power Transfer Evaluation Board
User’s Guide
_____________________________________________________________________________________________________________________
GSWP100W-EVBPA Rev 180529 © 2018 GaN Systems Inc. www.gansystems.com 20
Please refer to the Evaluation Board/Kit Important Notice on page 26
Figure 19 • Spectrum Plot of output terminal JP56 SMA after 49.66dB attenuation at 100W output power
Figure 20 • Output power and efficiency of PA without EMI filter at JP56 SMA
Note: With the EMI filter, the maximum power level is limited to 80W, due to the 50Ω test.
The PA’s system reliability is optimized when the temperature rise of each device is kept to a minimum,
including that of the GaN E-HEMTs. The GS61008Ps are especially well suited in this regard, for a
number of reasons. First, they have very low switching losses which allows them to operate at high
efficiency and a low temperature rise at 6.78MHz, the common frequency used for resonant wireless
50.0%
55.0%
60.0%
65.0%
70.0%
75.0%
80.0%
85.0%
90.0%
95.0%
0
10
20
30
40
50
60
70
80
10 15 20 25 30 35 40
Eff(%)
Pout(W)
Vin(V)
100W WPT PA Pout(W) & Efficiency(%) without EMI filter
Pout(W) Eff(%)