P9222-R/RN Datasheet

© 2019-2022 Renesas Electronics Corporation

40

May 5, 2022

9.4.1 Configuring FOD Parameters

FOD parameters consist of 8 sections. Each section is divided by output current and consists of gain and offset to compensate for Rx internal

power loss; each section is also adjusted for Reported Rx power. The following comprises the mA ranges for the FOD sections:



FOD section [0] is from 0mA to 191mA



FOD section [1] is from 192mA to 351mA



FOD section [2] is from 352mA to 511mA



FOD section [3] is from 512mA to 671mA



FOD section [4] is from 672mA to 819mA



FOD section [5] is more than 820mA

The formula of Rx Reported Power is:

������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������[0..5]=������������������������������������������������������������(������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������)∗������������������������������������������������������������������������������������[0…5]+������������������������������������������������������������������������[0..5] Equation6

Place the receiver with the P9222-R/RN on the Nok9 FOD transmitter. Ramp the current on the output of the P9222-R/RN in steps of 50mA to

100mA and monitor power difference between the Nok9 transmitted power and the receiver reported power value. The difference should be

within 0-350mW. If the difference exceeds 350mW, adjust the FOD gain or FOD offset of that particular output current section in order to bring

the difference back to 0-350mW range. The AP can modify the FOD gain and FOD offset by writing to the Foreign Object Detection Registers

(0x70-0x7E). In the final product, the AP can use the VRECTON interrupt or battery charger interrupt as a trigger to update the FOD registers.

The default values of the FOD registers can also be configured by the following writing a configuration file into the external EEPROM. To

generate the configuration file using the P9222-R/RN Windows GUI:

1. Place the receiver with the P9222-R/RN onto the WPC transmitter or apply 5V from an external power supply on the VRECT node.

2. Launch the P9222-R/RN GUI, go to the “Config” tab, click the “Rd EEPROM” button, and then click the “FOD” button. A new popup window

with the current FOD values stored in the external EEPROM will be displayed.

3. Enter new FOD values and click on the “Save cfg file” to generate a new configuration.

The configuration can also be directly written into the external EEPROM by clicking the “Wr EEPROM” button. Note: The Write Protect

function on the EEPROM must be disabled before writing to the EEPROM.

Figure 34. Changing the Default FOD Registers using the P9222-R/RN Windows GUI