EM4170

Copyright

 2002, EM Microelectronic-Marin SA

1

www.emmicroelectronic.com

125kHz CRYPTO READ/WRITE Contactless Identification Device

Description

The EM4170 is a CMOS integrated circuit intended for

use in electronic Read/Write RF Transponders. The chip

contains an implementation of a crypto-algorithm with 96

Bits of user configurable secret-key contained in

EEPROM. It also provides a unique Device Identification

of 32 bits that can never be modified as well as 94 bits of

freely programmable USER-MEMORY. Bits 15 and 14

of word 1 are used as Lock-Bits. The memory can only

be accessed for writing or erasing if these two bits have

the contents "x0" as when they are delivered.

The memory can be unlocked by using the PIN-code

command. In that case, the lock-bits are reset from the

value "x1" to the value "x0".

The EM4170 transmits data to the transceiver by

modulating the amplitude of the electromagnetic field,

and receives data and commands in a similar way.

The coil of the tuned circuit is the only external

component required, all remaining functions

are

integrated in the chip.

Features

•

On Chip Crypto-Algorithm

•

Two Way Authentication

•

96 bits of Secret-Key in EEPROM (unreadable)

•

32 bits of fix Device Identification

•

32 bits of PIN code (unreadable)

•

94 bits of USER_MEMORY (UM) with read access

(OTP)

•

Secret-Key programmable via CID-Interface

•

Lock-Bits to inhibit programming

•

Data

Transmission

performed

by

Amplitude

Modulation

•

Bit Period = 32 periods of carrier frequency

•

200pF on chip Resonant Capacitor (untrimmed)

•

-40 to +85°C Temperature range

•

100 kHz to 150 kHz Field Frequency

•

On chip Rectifier and Voltage Limiter

•

No external supply buffer capacitance needed due

to low power consumption

Typical Applications

• Anti-counterfeiting

• High security hands-free access control

Typical Operating Configuration

Fig. 1

COIL1

EM4170

L

COIL2