Summary description

SRI512

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Summary description

The SRI512 is a contactless memory, powered by an externally transmitted radio wave. It

contains a 512-bit user EEPROM fabricated with STMicroelectronics CMOS technology.

The memory is organized as 16 blocks of 32 bits. The SRI512 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 sub-carrier. The received

ASK wave is 10% modulated. The Data transfer rate between the SRI512 and the reader is

106kbit/s in both reception and emission modes.

The SRI512 follows the ISO 14443 part 2 type B recommendation for the radio-frequency

power and signal interface.

Figure 1.

Logic Diagram

The SRI512 is specifically designed for short range applications that need re-usable

products. The SRI512 includes an anti-collision mechanism that allows it to detect and

select tags present at the same time within range of the reader. Using the

STMicroelectronics single chip coupler, CRX14, it is easy to design a reader and build a

contactless system.

Table 1.

Signal Names

AC1

Antenna Coil

AC0

Antenna Coil

AI10795

AC1

SRI512

AC0

Power

Supply

Regulator

BPSK

Load

Modulator

ASK

Demodulator

512-bit

User

EEPROM