Description

SR176

6/35

1

Description

The SR176 is a contactless memory, powered by an externally transmitted radio wave. It

contains 176 bits of user EEPROM, fabricated with STMicroelectronics CMOS technology.

The memory is organized as 16 blocks of 16 bits, of which 11 blocks are user accessible.

The SR176 is accessed via the 13.56 MHz carrier. Incoming data are demodulated and

decoded from the received Amplitude Shift Keying modulation signal (ASK). The modulation

index of this signal is 10%. Outgoing data are generated by load variation using Bit Phase

Shift Keying (BPSK) of a 847.5 kHz subcarrier. The Data transfer rate between the SR176

and the reader is 106 Kbit/s in both reception and emission modes.

The SR176 follows the ISO 14443-2 Type B recommendation for radio frequency power and

signal interfacing.

Figure 1.

Pad connections

The SR176 is principally designed for short range applications, such as object identification,

that need a low cost and non-reusable tag. The SR176 does not include any anticollision

mechanism. It provides an “addressed” selection mechanism to cope with cases where

more than one tag is present within the range of the reader.

The SR176 contactless EEPROM offers read and write random access in block mode. One

block is composed by 16 bits. The device has an instruction set containing seven

commands:

●

READ_BLOCK

●

WRITE_BLOCK

●

INITIATE

●

SELECT

●

COMPLETION

●

PROTECT_BLOCK

●

GET_PROTECTION.

Table 1.

Signal names

AC1

Antenna coil

AC0

Antenna coil

AI09057

AC1

SR176

AC0

Power

Supply

Regulator

BPSK

Load

Modulator

ASK

Demodulator

176 bit

USER

EEPROM