mfrc522 NXP Semiconductors, mfrc522 Datasheet - Page 61

• Manufacturer Part Number: mfrc522
• Description: Contactless Reader Ic
• Manufacturer: NXP Semiconductors

Table 145: Settings for TX1
NXP Semiconductors
11. Analog Interface and Contactless UART
112132
Product data sheet
TX1RFEn
0
1
100ASK
Force
11.1 General
11.2 TX Driver
X
0
0
1
The integrated contactless UART supports the external host online with framing and error
checking of the protocol requirements up to 848 kbit/s. An external circuit can to be
connected to the communication interface pins MFIN/MFOUT to modulate and
demodulate the data.
The contactless UART handles the protocol requirements for the communication schemes
in co-operation with the host. The protocol handling itself generates bit- and byte-oriented
framing and handles error detection like Parity and CRC according to the different
contactless communication schemes.
Remark: The size and the tuning of the antenna and the power supply voltage have an
The signal delivered on pin TX1 and pin TX2 is the 13.56 MHz energy carrier modulated
by an envelope signal. It can be used to drive an antenna directly, using a few passive
components for matching and filtering, see
signal on TX1 and TX2 can be configured by the register TxControlReg, see
9.2.2.5
The modulation index can be set by adjusting the impedance of the drivers. The
impedance of the p-driver can be configured by the registers CWGsPReg and
ModGsPReg. The impedance of the n-driver can be configured by the register GsNReg.
Furthermore, the modulation index depends on the antenna design and tuning.
The register TxModeReg and TxAutoSelReg control the data rate and framing during
transmission and the setting of the antenna driver to support the different requirements at
the different modes and transfer speeds.
InVTx1
RFON
x
0
1
1
“TxControlReg”.
important impact on the achievable operating distance.
RFOFF
InVTx1
X
x
x
x
Envelope
Rev. 3.2 — 22 May 2007
x
0
1
0
1
0
1
RF_n
TX1
RF
RF
RF
RF
x
0
Section 24 “Application
GSPMos
pMod
pMod
pMod
pCW
pCW
pCW
x
GSNMos Remarks
nMod
nMod
nMod
nCW
nCW
nCW
x
not specified if RF is
switched off
100% ASK: TX1 pulled to
0, independent of
InvTx1RFOff
Contactless Reader IC
information”. The
MFRC522
© NXP B.V. 2007. All rights reserved.
Section
61 of 109