P9221-R3 Datasheet

© 2017 Integrated Device Technology, Inc.

20

October 20, 2017

8.12 Received Power Packet Offset and Gain Calibration – RPPO and RPPG

The received power packet offset (RPPO) and received power packet gain (RPPG) calibrations utilize dedicated pins for tuning foreign object

detection (FOD). These calibrations tune the received power packet via the voltage levels on the RPPO and RPPG pins, which are determined

by the external resistors in divider networks on the 1.8V bias voltage. The voltage level on the RPPO pin is used to add offset in order to shift

the Received Power Packet (RPP) globally, and the voltage level on the RPPG pin adjusts the slope gain of the Received Power Packet (RPP).



The received power packet offset calibration can be tuned by varying the voltage on the RPPO pin from 0.1V to 2.1V corresponding to a

power offset range from -1.56W to 2.34W.



The received power packet gain can be tuned by varying the voltage on the RPPG pin from 0.1V to 2.1V corresponding to a gain setting

in the range from 0.111 to 2.33.



To disable the FOD, the RPP0 and RPPG must be connected to GND.

The RPP is adjusted according to Equation 2:

RPP [mW] = Pmeasured [mW] ×

RPPG [%]

1755 [%]

+ RPPO [mW] – 1755 [mW]

Equation 2

Where

RPP = Reported Received Power

Pmeasured = measured power from output voltage and current

RPPO [mW] =

VRPPO [V]

2.1 [V]

× 4095 [mW]

Equation 3

RPPG [%] =

VRPPG [V]

2.1 [V]

× 4095 [%]

Equation 4

For example, if the voltage on the RPPO and RPPG pins is 0.9V then the RPP will have no offset or gain. The RPP will be exactly the same as

the measured power in the receiver.