The HCS301 from Microchip Technology Inc. is a code hopping encoder designed for secure Remote Keyless Entry (RKE) systems. It features a programmable 28-bit serial number, programmable 64-bit encryption key, unique transmission for each transmission, 66-bit transmission code length, 32-bit hopping code, and 34-bit fixed code.
The HCS301 encoder is designed for Remote Keyless Entry (RKE) applications such as automotive door locks, garage door openers and alarm systems. It offers a 66‑bit transmission code, four button inputs, selectable baud rates and low‑cost external components.
Technical details include a 192‑bit EEPROM memory map, a 28‑bit programmable serial number, a 64‑bit encryption key, and configurable synchronization and configuration words. The device operates from 3.5 V to 13.0 V and includes features like an auto‑shutoff timer and low‑voltage trip point selection.
| Operating voltage | 3.5 V – 13.0 V |
|---|---|
| EEPROM size | 192 bits (12 × 16‑bit words) |
| Transmission code length | 66 bits |
| Hopping code length | 32 bits |
| Fixed code length | 34 bits (28‑bit serial number, 4‑bit button code, 2‑bit status) |
| Button inputs | 4 |
| Functions available | 15 |
| Auto‑shutoff timer | Enabled when MSB of serial number is 1 (≈25 s) |
The encoder operates from 3.5 V to 13.0 V.
It provides four button inputs.
The device contains 192 bits of EEPROM memory, organized as 12 × 16‑bit words.
Each transmission uses a 66‑bit code word.