GENERAL DESCRIPTION

The HCS412 combines patented KEELOQ code hopping technology with bi-directional transponder challenge-and-response security into a single chip solution for logical and physical access control.

When used as a code hopping encoder, the HCS412 is ideally suited to keyless entry systems; vehicle and garage door access in particular. The same HCS412 can also be used as a secure bi-directional transponder for contactless token verification. These capabilities make the HCS412 ideal for combined secure access control and identification applications, dramatically reducing the cost of hybrid transmitter/transponder solutions.

FEATURES

Security

? Programmable 64-bit encoder crypt key

? Two 64-bit IFF keys

? Keys are read protected

? 32-bit bi-directional challenge and response using one of two possible keys

? 69-bit transmission length

? 32-bit hopping code,

? 37-bit nonencrypted portion

? Programmable 28/32-bit serial number

? 60-bit, read protected seed for secure learning

? Two IFF encryption algorithms

? Delayed counter increment mechanism

? Asynchronous transponder communication

? Transmissions include button Queuing information

Operating

? 2.0V to 6.3V operation

? Three switch inputs: S2, S1, S0 – seven functions

? Battery-less bi-directional transponder capability

? Selectable baud rate and code word blanking

? Automatic code word completion

? Battery low detector

? PWM or Manchester data encoding

? Combined transmitter, transponder operation

? Anticollision of multiple transponders

? Passive proximity activation

? Device protected against reverse battery

? Intelligent damping for high Q LC-circuits

? 100 mVPP sensitive LC input

Typical Applications

? Automotive remote entry systems

? Automotive alarm systems

? Automotive immobilizers

? Gate and garage openers

? Electronic door locks (Home/Office/Hotel)

? Burglar alarm systems

? Proximity access control

Other

? Simple programming interface

? On-chip tunable RC oscillator, ± 10

? On-chip EEPROM

? 64-bit user EEPROM in Transponder mode

? Battery-low LED indication

? Serialized Quick Turn Programming (SQTPSM)

? 8-pin PDIP/SOIC

? RF Enable output

? ASK and FSK PLL interface option

? Built in LC input amplifier