EM4055

Copyright

© 2002, EM Microelectronic-Marin SA

1

www.emmicroelectronic.com

1KBIT Read/Write Contactless Identification Device

with anticollision

Description

The EM4055 is a CMOS integrated circuit for passive

read/write RF-transponders operating in the low frequency

range (125kHz typically). The chip contains 1kbit of

EEPROM which can be configured by the user allowing

write inhibited words, read protected words and read area

output continuously at power-on. The memory can be

secured by using the 32-bit password for all write and

read protected operations. The password can be updated

but never read. The fixed code anticollision ID and device

identification are programmed once, and then locked. The

chip can be configured to start at power on in QUIET

mode, or in Standard read mode. The EM4055 will

transmit data to the reader by modulating the amplitude of

the magnetic field, and receive data and commands by

100%

modulation

induced

by

the

reader.

Simple

commands allow writing to EEPROM, updating the pass-

word, read a specific memory area, perform the

anticollision procedure, and reset the logic. The coil and

capacitor of the tuned LC circuit are the only external

components required.

Applications

• Ticketing

• Hands free Access control

• Inventory Control

• Prepayment devices

• Manufacturing automation with portable database

• Industrial logistics

Features

• 1k bit EEPROM (32 words of 32 bit each)

• User defined Read memory area as default output

• User defined Write protected words

• User defined Read protected words

• Power-check before EEPROM Write operation

• 32 bits WORM anticollision ID

• 32 bits WORM device identification

• Fast Anticollision Protocol for a large number of

Transponders

• Detection of Tag entering the field

• Data transmission performed by amplitude modulation

Reader to transponder : ASK 100%, Transponder to

Reader : ASK

• User selectable data-rate : RF/64 or RF/32

• 100kHz to 150kHz field frequency range

• On-chip rectifier and voltage limitation

• On-chip supply buffer capacitor

• Power-on Reset

• -40 to +85°C operating temperature range

Typical Operating Configuration

C2

C1

EM4055

C

L

Typical configuration at 125 kHz uses a coil of 4.9 mH

and a 330 pF capacitor

Fig. 1