Microchip Technology HCS301-I/P

The HCS301 generates a 66-bit transmitted code word from a 32-bit hopping portion and 34 fixed information bits. A programmable 64-bit crypt key and 28-bit serial number are stored with synchronization and configuration information in on-chip EEPROM. Four switch inputs select transmitter functions; the PWM output carries the encoded data to external transmitter circuitry.

Original LCDChip registration: 8-DIP (0.300", 7.62mm). Microchip's HCS301 identification table defines the /P suffix as an eight-lead plastic DIP with a 300-mil body. Check the manufacturer's controlled drawing, row spacing and pin-one orientation before selecting a socket or PCB footprint; the /SN SOIC option is not mechanically interchangeable.

Layout checks

• Confirm 300-mil body and through-hole row spacing.
• Keep VDD and VSS wiring within the rated supply range.
• Route PWM to appropriate transmitter circuitry, not directly to an antenna.

The expected local JPG is absent and the production image returns HTTP 404. Keep the detail unpublished until the correct image is restored and inspected.

Microchip's eight-pin HCS301 pin table assigns S0, S1, S2 and S3 switch inputs to pins 1 through 4. S2 doubles as the programming clock. Pin 5 is VSS, pin 6 is PWM output/programming data, pin 7 is the LED cathode connection and pin 8 is VDD.

Observe the manufacturer's programming and application circuits before multiplexing switch and programming functions.

Values are from the manufacturer's HCS301 data sheet DS21143C. Confirm receiver protocol, timing and power-circuit details for the final application.

Microchip describes HCS301 as functionally identical to HCS300, but any substitution still requires review of the exact order code, package, programmed key material, serial-number policy, receiver learning method and synchronization behavior. The HCS301 /SN version uses SOIC rather than the registered through-hole DIP footprint. No unverified internal alternative is linked.

Microchip Technology's HCS301 KEELOQ Code Hopping Encoder data sheet DS21143C provides the official feature list, pin descriptions, programming and code-word information, and the product identification table confirming the I/P industrial-temperature 300-mil DIP order code.

Inspect top marking, date and lot traceability, 300-mil DIP geometry and pin-one indication. Verify the programmed serial number and key policy using authorized test fixtures, then confirm receiver learning and synchronization under repeated button activations. Protect programming records and manufacturer-code secrets.

Use the controlled Microchip programming flow; safeguard the manufacturer code, unique crypt keys and receiver learn records. Validate the complete RF transmitter and receiver system, supply network and DIP footprint. Restore and inspect the live package JPG before formal publication.