Datasheet

Product data sheet

COMPANY PUBLIC

Rev. 5.2 — 16 June 2016

111352 86 of 137

NXP Semiconductors

PN512

Full NFC Forum-compliant frontend

The sensitivity of the RF level detector is adjustable in a 4-bit range using the bits RFLevel

in register RFCfgReg. The sensitivity itself depends on the antenna configuration and

tuning.

Possible sensitivity levels at the RX pin are listed in the Table 154

To increase the sensitivity of the RF level detector an amplifier can be activated by setting

the bit RFLevelAmp in register RFCfgReg to 1.

Remark: During soft Power-down mode the RF level detector amplifier is automatically

switched off to ensure that the power consumption is less than 10 Aat3V.

Remark: With typical antennas lower sensitivity levels can provoke misleading results

because of intrinsic noise in the environment.

Note: It is recommended to use the bit RFLevelAmp only with higher RF level settings.

11.4 Data mode detector

The Data mode detector gives the possibility to detect received signals according to the

ISO/IEC 14443A/MIFARE, FeliCa or NFCIP-1 schemes at the standard transfer speeds

for 106 kbit, 212 kbit and 424 kbit in order to prepare the internal receiver in a fast and

convenient way for further data processing.

The Data mode detector can only be activated by the AutoColl command. The mode

detector resets, when no external RF field is detected by the RF level detector. The Data

mode detector could be switched off during the AutoColl command by setting bit

ModeDetOff in register ModeReg to 1.

Table 155. Setting of the bits RFlevel in register RFCfgReg (RFLevel amplifier deactivated)

V~Rx [Vpp] RFLevel

~2 1111

~1.4 1110

~0.99 1101

~0.69 1100

~0.49 1011

~0.35 1010

~0.24 1001

~0.17 1000

~0.12 0111

~0.083 0110

~0.058 0101

~0.041 0100

~0.029 0011

~0.020 0010

~0.014 0001

~0.010 0000