Antenna Presence Self Test; Principle - NXP Semiconductors PN5331B3HN Manual

NXP Semiconductors

8.6.9 Antenna presence self test

8.6.9.1 Principle

PN5331B3HN
Product data sheet
COMPANY PUBLIC
The goal of the Antenna Presence Self Test is to facilitate at assembly phase the
detection of the absence of the antenna and/or antenna matching components. Such a
detection is done by mean of measuring the current consumption.
The principle is explained with typical antenna tuning and matching components.
RX
VMID
PN533
TX1
TVSS1
TVSS2
TX2
Fig 49. Disconnection localization for the antenna detection
The testing operation can be managed via a dedicated register
and requires the transmitter to be activated. When activated by asserting bit 0, the
detector will monitor the current consumption through the internal low dropout voltage
regulator. Any violation to the current limits will be reported via bits 7 and 6 of the register.
Several levels of detection can be programmed through the register to offer a large panel
of compatibility to different type of antennas. The high current threshold can be
programmed from 40 mA to 150 mA with 15 mA steps (total current consumption of the
IC). The low current threshold can be programmed from 5mA to 35 mA with 10 mA step
(total current consumption of the IC).
There is no dedicated pin for the output of the detector. The result of the detection is to be
read out from the antenna test register.
All information provided in this document is subject to legal disclaimers.
Rev. 3.4 — 29 November 2017
Near Field Communication (NFC) controller
C
Rx
R
R
1
2
C
vmid
C
L
1
0
C
0
C
0
L
C
0
1
2
3
157534
PN5331B3HN
R
Q
C
2
Antenna
C
2
R
Q
1
Table 159 on page 128
© NXP B.V. 2017. All rights reserved.
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