Infineon WLC1150 User Manual page 11

WLC1150 MP-A2 50-W wireless power transmitter
(REF_WLC_TX50W_N1) user guide
WLC1150 wireless power transmitter system design
(J1). There is also an option for a DC power supply connection (J3) to deliver power with a High Power
Infineon receiver board (
can be active.
2. Fan regulator for powering the fan- The fan regulator is having buck converter stage to regulate VFAN
voltage to 5 V for powering the fan.
3. Fan for thermal management- The fan is operated for thermal management of the interface surface. It
operates when power transfer by Tx is more than 40 W or Tx interface surface temperature is more than
45°C, which is measured by NTC on the Tx board. The fan will turn off after the Tx- power falls below 35 W or
coil temperature falls below 40°C.
4. Inverter stage – The full-bridge inverter (Q4 to Q7) is operated at a frequency range of 110 kHz – 145 kHz to
drive the resonant tank formed by the transmitter coil (Lr) and resonant capacitors (Cr). The coil voltage
feedback (COIL-SNS) is used for Q-factor estimation and ASK demodulator circuits.
5. Transmitter coil assembly – The transmitter coil is MP-A2 type with specifications per Qi standards. The
coil is mounted on a separate coil PCB. A set of PCB shield (Shield PCB TOP and Shield PCB BOT) is mounted
on top of the coil and an acrylic sheet form the interface surface of the transmitter. The coil mounting
adhesive, spacers, and acrylic thickness are selected such that the distance between the coil top surface
and to interface surface is approximately 3.1 mm (Qi specification: 3 mm + 0.5 mm/-0.25 mm). See
for coil assembly details.
Coil assembly
Figure 5 MP-A2 transmitter coil assembly
5. WLC1150-68LQXQ – The WLC1150 is a single controller unit to control the transmitter coil and USB PD
interface. The WLC1150 simplifies the transmitter board architecture with inbuilt gate drivers for the
auxiliary buck and inverter stage, inbuilt LDO for logic and core power, and more features. With an on-chip
32-bit Arm® Cortex®-M0 processor, 128-KB flash, 16-KB RAM, and 32-KB ROM, the firmware supporting the
complete high-power proprietary protocol and USB PD state machine logic can be programmed onto the
WLC1150 controller.
6. ASK demodulator – The ASK demodulator is based on coil voltage and bridge current. The demodulated
signal from both paths is processed through a dual opamp-based gain stage and a comparator and decoded
by the WLC1150 controller.
7. Q-factor and resonance frequency estimation – The Q-factor estimation from coil voltage is performed by
WLC1150 through the signal at Q_COMP. The coil voltage is processed through a blocking capacitor, voltage
divider, and clamping diode to feed to the WLC1150 controller for Q-factor and resonance frequency
estimation.
8. Status indication – The firmware indicates the various system states or events using the dual-color (red
and blue) status LED (LED1). See the
User guide
REF_WLC_RX50W_N1
PCB thickness – 1.6 mm
Acrylic thickness – 1.88 mm
Shield PCB Thickness – 0.6 mm Each
Spacer height – 4.8 mm
PCB + adhesive + Coil assembly – 4.9 mm
Dz gap – 3.08 mm
Acrylic
Shield PCB TOP
Shield PCB BOT
Adhesive
Reference board operation
). Note that at any point in time, only one input power source
.
to understand more details.
11
Figure 5
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PCB
002-36393 Rev. *B
2023-02-06