GENERAL DESCRIPTION

The HCS473 combines the patented KEELOQ code hopping technology and bi-directional transponder challenge-and-response security into a single chip solution for logical and physical access control.

The three-input transponder interface allows the combination of three orthogonal transponder antennas, eliminating the directionality associated with traditional single antenna transponder systems.

FEATURES

Encoder Security

• Read protected 64-bit encoder key

• 69-bit transmission length

• 60-bit, read protected seed for secure learning

• Programmable 32-bit serial number

• Non-volatile 16/20-bit synchronization counter

Encoder Operation

• 2.05V to 5.5V operation

• Four switch inputs – up to 15 functions codes

• PWM or Manchester modulation

• Selectable Baud Rate (416 - 5,000 bps)

• Transmissions include button queuing information

• PLL interface

Transponder Security

• 2 read protected 64-bit Challenge/Response keys

• Two IFF encryption algorithms

• 16/32-bit Challenge/Response

• Separate Vehicle ID and Token ID

• 2 vehicles supported

• CRC on all communication

Transponder Operation

• Three sensitive transponder inputs

• Bi-directional transponder communication

• Transponder in/RF out operation

• Anticollision of multiple transponders

• Intelligent damping for high Q-factor LC-circuits

• Low battery operation

• Passive proximity activation

• 64-bit secure user EEPROM

• Fast reaction time

Peripherals

• Low Voltage Detector

• On-board RC oscillator with ±10% variation

Typical Applications

• Passive entry systems

• 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

• Passive proximity authentication