sri4k STMicroelectronics, sri4k Datasheet - Page 7

• Manufacturer Part Number: sri4k
• Description: 13.56 Mhz Short-range Contactless Memory Chip With 4096-bit Eeprom And Anticollision Functions
• Manufacturer: STMicroelectronics

SRI4K
1
Description
The SRI4K is a contactless memory, powered by an externally transmitted radio wave. It
contains a 4096-bit user EEPROM fabricated with STMicroelectronics CMOS technology.
The memory is organized as 128 blocks of 32 bits. The SRI4K is accessed via the
13.56MHz carrier. Incoming data are demodulated and decoded from the received
Amplitude Shift Keying (ASK) modulation signal and outgoing data are generated by load
variation using Bit Phase Shift Keying (BPSK) coding of a 847kHz subcarrier. The received
ASK wave is 10% modulated. The Data transfer rate between the SRI4K and the reader is
106kbit/s in both reception and emission modes.
The SRI4K follows the ISO 14443 part 2 type B recommendation for the radio-frequency
power and signal interface.
Figure 1.
The SRI4K is specifically designed for short range applications that need re-usable
products. The SRI4K includes an anticollision mechanism that allows it to detect and select
tags present at the same time within range of the reader. The anticollision is based on a
probabilistic scanning method using slot markers. Using the STMicroelectronics single chip
coupler, CRX14, it is easy to design a reader and build a contactless system.
Table 1.
AC1
AC0
Logic diagram
Signal names
EEPROM
4 Kbit
User
Antenna Coil
Antenna Coil
SRI4K
Demodulator
Modulator
Regulator
Supply
Power
BPSK
Load
ASK
AI10878
AC0
AC1
Description
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