NXP Semiconductors MP-A11 Series User manual

© 2019 NXP B.V.
WCT1012VLF/WCT1013VLH Consumer MP-
A11 (WCT-15W1CFFPD) V1.0 Wireless
Charging Application User’s Guide
1.Key features
The WCT1012VLF/WCT1013VLH Consumer MP-
A11_Rev1.0 (MP-A11_Rev1_SCH-32212_B, MP-
A11_Rev1_LAY-32212_B) wireless charging TX demo
(WCT-15W1CFFPD) is used to wirelessly transfer power
to a charged device. The charged device can be any
electronic device equipped with a dedicated Qi wireless
charging receiver.
The main parameters of the Wireless Charging
Transmitter (WCT) are:
•Support for QC 3.0 and USB PD 2.0/3.0 input.
The input voltage ranges from 5 to 19 V DC.
•The input voltage can drop down to 5 V DC
during the start-stop function.
•The nominal power delivered to the receiver is
15 W, up to 22 W (at the output of the receiver)
and compatible with a 5 W receiver.
•Designed to meet the Qi 1.2.4 specification.
•Operation frequency: 120 kHz ~ 130 kHz (the
default is 127.772 kHz) for Qi devices.
NXP Semiconductors
Document Number: WCT101XV10AUG
User’s Guide
Rev. 1
,,
05/2019
1. Key features....................................................................... 1
2. Hardware setup.................................................................. 2
3. Application operation ........................................................ 6
4. Hardware description......................................................... 6
5. Application monitoring and control using FreeMASTER 15
6. Application monitoring using console..............................20
7. Programming new software and calibration .....................22
8. Software description.........................................................46
9. System bring up................................................................52
10. Revision history................................................................56
Contents

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2.Hardware setup
2.1. Package contents
1. WCT Consumer MP-A11 (WCT-15W1CFFPD) demo board.
Figure 1. MP-A11 (WCT-15W1CFFPD) demo board

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2.2. Board description
The WCT board is powered through the on-board power connector.
The connectors on the upper-middle part of the board provides the JTAG connection for programming
and debugging and 1xUART for the FreeMASTER tool connection for the debug option and console
connection. The I2C connector is placed on the upper left-hand side of the board.
Figure 2 shows the device.
Coil
I2C UARTJTAG
DSC
USB PD
Buck
FB
Invertor
Power
Figure 2. Device overview
2.3. Powering the board on
To power the board on, perform these steps:
1. Plug the USB PD or QC adaptor.
2. Connect the board with the USB PD or QC adaptor by an USB type-C cable.

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Figure 3. Power supply components
2.4. Hardware setup for FreeMASTER and console communication
To set up the hardware for the FreeMASTER and console communication, perform these steps:
1. Find the UART-to-USB adapter on the board and install the UART-to-USB device driver on the
computer. The virtual serial port on the computer should work well.
2. Plug the USB-UART converting board to the SCI connector according to the SCH signal pin
position.

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Figure 4. UART and JTAG connectors

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3.Application operation
Connect the demo to the USB PD or QC adaptor using a cable. The WCT starts to periodically send the
power ping to check whether a compatible Wireless Charging Receiver (WCR) is placed on the charging
surface.
When a Qi-compliant receiver is placed on the top of the TX coil area, the WCT starts the charging
process. If there is no correct Qi answer from the WCR side, the TX does not start the Qi charging
process.
If the WCR answers properly, the power transfer starts. The actual level of the transferred power is
controlled by the WCT in accordance with the WCR requirements. The receiver sends messages to the
WCT through the ASK on the coil resonance power signal and the transmitter sends the information to
the receiver using FSK, as per the Qi specification. The power transfer is terminated when the receiver is
removed from the WCT magnetic field.
The system supports all Qi WCR devices: Qi_Ver-1.0 compliance, Qi_Ver-1.1 compliance, and the Qi
EPP receiver. The system supports all the FOD features for different receivers. For the BPP receiver, the
power loss FOD is supported. For the EPP receiver, both the Q-value FOD method and the power loss
FOD method are supported.
4.Hardware description
Figure 5 shows the block diagram of the consumer wireless charger MP-A11 (WCT-15W1CFFPD).
Visit www.nxp.com to get the latest hardware design files.
The whole design consists of several blocks, which are described in the following sections.

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Figure 5. Block diagram of the consumer wireless charger MP-A11 (WCT-15W1CFFPD)

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4.1. Input EMI filter
The input filter consists of the common-mode filter FL1 and filter capacitors C2, C3, C5, C7, and L1.
4.2. USB power supply
A USB type-C cable can be plugged to the USB type-C connector J2. The PTN5110 USB PD PCTC
PHY is selected to support the type-C Configuration Channel (CC) interface and the USB PD physical
layer functions.
The MPA-11 design also supports the Qualcomm Quick Charge 2.0/3.0 technology. The WCT
controller manages the Qualcomm QC 2.0/3.0 protocol through the GPIOs and resistors connected to the
D+/D- data line.
Figure 6. USB PD power supply and QC circuits
4.3. System voltage DCDC
The USB PD or QC adaptor input is connected to buck converter U12 (MP2314). Its output is 3.3 V.
This 3.3 V output is mainly for the WCT1012VLF/WCT1013VLH and other 3.3 V-powered
components. Generally, the DCDC load current is low. It is preferable to select a DCDC with a high
efficiency in the light-load condition.
The MP-A11 design can also support other customized-propriety power protocols.

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4.4. Rail voltage generated by analog buck chip
The Qi specification for the MP-A11 topology requires the DC voltage control to control the power
transferred to the receiver. The buck converter is selected to get the regulated DC voltage ranging from
3 V DC to 18 V DC for the full-bridge inverter power supply. The buck is controlled by the individual
analog buck converter and the WCT chip only controls the output voltage feedback.
For the analog buck module, MP2229 (or a similar IC like SY8286) is selected to generate the rail
voltage. The WCT chip generates one analog signal from the PWM and controls the rail voltage using
this signal. This analog signal adjusts the analog buck converter feedback, and the system can get the
rail voltage as the system expects.
Figure 7. Analog buck-boost main circuits
4.5. Full-bridge and resonant circuits
The full-bridge power stage consists of integrated power stage unit (U7 and U8). The MOSFETs and
their driver are integrated inside the power stage unit. The full-bridge power stage converts the variable
DC voltage VRAIL to the square-wave 50 % duty-cycle voltage with a default frequency of 127.772
kHz. The range of the frequency used (from 120 kHz to 130 kHz) is defined in the Qi specification for
the MP-A11 topology.
The resonant circuits consist of C81, C82, C83, C84, C85, and coils, all of which are fixed values
defined in the Qi specification for the MP-A11 topology. The snubber RC pairs connected in parallel to
the integrated power stages are used to lower the high frequency of the EMI products. The Vrail
discharge circuit (Q4 and R58) is switched ON while the system is terminated.

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Figure 8. Full bridge circuits
4.6. Communication
There is bi-way communication between the EPP power transceiver and receiver. Communication from
RX to TX: The RX measures the received power and sends the information about the required power
level back to the transmitter. This message is Amplitude Modulated (AM) on the coil current and sensed
by the TX.
The RC circuits C87, R87, R88, and R92 (known as DDM) sample the signal from the coil, compress
the signal amplitude, and feed it to the ADC B-channel of the WCT1012VLF/WCT1013VLH. The
information about the current amplitude and modulated data are processed by the embedded software
routine.
Communication from TX to RX: The TX shall negotiate with the RX in the negotiation phase (if requested
by the RX). The TX uses the FSK modulation to communicate with the RX, and the communication
frequency is about 512 times the operating frequency.
4.7. FOD based on power loss
The power loss , which is defined as the difference between the Transmitted Power  and the
Received Power , i.e.    , provides the power absorption in foreign objects, as shown
in Figure 9.