HCS301/P

The HCS301/P from Microchip Technology is a secure code hopping encoder utilizing KEELOQ® technology for Remote Keyless Entry (RKE) applications. This IC is designed for unidirectional remote keyless entry and access control systems, offering high security through its unique transmission code mechanism.

Key features include a programmable 28-bit serial number and a programmable 64-bit encryption key. Each transmission is unique, with a 66-bit code word comprising a 32-bit hopping code and a 34-bit fixed code. The device supports operation from 3.5V to 13.0V and includes four button inputs, with 15 functions available. It also provides a battery low signal and indication.

The HCS301/P is housed in an 8-PDIP package and is designed for through-hole mounting. Its on-chip EEPROM stores encryption keys, serial numbers, and configuration data, which are read-protected for enhanced security. The device also features an on-chip oscillator and timing components, internal pull-down resistors on button inputs, and current limiting on the LED output, minimizing external component requirements.

Typical applications include automotive RKE systems, alarm systems, immobilizers, gate and garage door openers, and identity tokens. The selectable baud rate and automatic code word completion simplify integration into various systems.