HCS412-I/P

Specialized ICS Overview

The HCS412-I/P is a KEELOQ code hopping encoder and transponder manufactured by Microchip Technology. It integrates bi-directional challenge-and-response security with code hopping technology for access control. The device operates on a supply voltage of 2.0V to 6.3V and features programmable 64-bit encryption keys, two 64-bit IFF keys, and a 69-bit transmission length comprising a 32-bit hopping code and a 37-bit non-encrypted portion. It supports asynchronous transponder communication, PWM or Manchester encoding, and includes an onboard RC oscillator with ±10% accuracy. The component is housed in an 8-pin PDIP package.

Specialized ICS Feature Summary

• KEELOQ Code Hopping: Utilizes a 64-bit crypt key and 32-bit synchronization counter to generate unique 69-bit transmissions, preventing code grabbing and scanning attacks.
• Bi-directional Transponder: Supports Identify Friend or Foe (IFF) authentication using one of two possible keys and algorithms via low-frequency inductive communication.
• Integrated Security Features: Includes read-protected keys, a 60-bit seed for secure learning, delayed counter increment mechanism, and automatic code word completion.
• Flexible Input/Output: Provides three switch inputs (S0, S1, S2) supporting seven functions, battery-low detection, LED indication, and selectable baud rates.

Specialized ICS Applications

• Automotive remote entry systems
• Automotive alarm systems
• Gate and garage openers
• Electronic door locks (Home/Office/Hotel)
• Proximity access control

Specialized ICS Procurement Notes

Verify the specific suffix 'I' indicates industrial temperature range operation (-40°C to +85°C) as per Microchip documentation. Confirm the 'P' suffix corresponds to the 8-pin PDIP package type. Check current availability status as this product family may have discontinued variants or limited stock depending on the distributor.

Specialized ICS Selection Notes

Select the HCS412 when both unidirectional code hopping and bidirectional transponder capabilities are required in a single component. Ensure the application supports the 2.0V to 6.3V operating voltage range. Verify that the system can accommodate the 69-bit transmission format and utilizes compatible KEELOQ decoders for authentication.

Specialized ICS Part Context

The HCS412 belongs to the Microchip KEELOQ product family, which specializes in secure wireless access solutions. It combines the functionality of traditional encoders like the HCS301 with transponder capabilities found in dedicated tokens. This integration reduces the bill of materials for hybrid transmitter/transponder applications compared to using separate discrete components.

Specialized ICS Replacement Considerations

Direct pin-compatible replacements within the same package may include other HCS4xx series devices if programming parameters match. However, due to the proprietary nature of KEELOQ keys and specific configuration bits, substitution requires verification of EEPROM content and decoder compatibility rather than simple electrical equivalence.