SRIX4K-SBN181GE STMICROELECTRONICS [STMicroelectronics], SRIX4K-SBN181GE Datasheet - Page 11

• Manufacturer Part Number: SRIX4K-SBN181GE
• Description: 13.56 MHz short-range contactless memory chip with 4096-bit EEPROM, anticollision and anti-clone functions
• Manufacturer: STMICROELECTRONICS [STMicroelectronics]

SRIX4K
3.2
3.2.1
3.2.2
Output data transfer from the SRIX4K to the reader (answer
frame)
The data bits issued by the SRIX4K use retro-modulation. Retro-modulation is obtained by
modifying the SRIX4K current consumption at the antenna (load modulation). The load
modulation causes a variation at the reader antenna by inductive coupling. With appropriate
detector circuitry, the reader is able to pick up information from the SRIX4K. To improve
load-modulation detection, data is transmitted using a BPSK encoded, 847 kHz subcarrier
frequency ƒ
Figure 7.
Character transmission format for answer frame
The character format is the same as for input data transfer
frames are made up of an SOF, data, a CRC and an EOF
transfer, if an error occurs, the reader does not issue an error code to the SRIX4K, but it
should be able to detect it and manage the situation. The data transfer rate is
106 Kbits/second.
Answer start of frame
The SOF described in
●
●
Figure 8.
Data Bit to be Transmitted
Generated by the SRIX4K
847kHz BPSK Modulation
followed by 10 ETUs at logic-0
followed by 2 ETUs at logic-1
ETU
s
0
Wave transmitted using BPSK subcarrier modulation
Answer start of frame
b0
to the Reader
as shown in
0
b1
Figure 8
Or
0
b2
Figure
0
b3
is composed of:
During a One-bit Data Transfer Time (1/106kHz)
7, and as specified in the ISO 14443-2 Type B Standard.
0
b4
BPSK Modulation at 847kHz
0
b5
0
b6
b7
0
(Figure
(Figure
b8
0
10). As with an input data
4). The transmitted
0
b9
1
b10
Data transfer
ai07665
1
b11
AI05730
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