Microchip Technology HCS365-I/SM

The HCS365 generates changing KEELOQ code words for remote-control transmitters. Two programmable serial numbers, crypt keys, and seed values support dual-encoder operation. Four button inputs allow up to 15 encoded functions, with configurable modulation and timing. The I/SM code identifies the industrial ordering option and an eight-lead wide-body surface-mount package.

• Two programmable 64-bit crypt keys and two 60-bit seed values.
• 32-bit hopping-code field and 67- or 69-bit transmission format depending on configuration.
• PWM, VPWM, PPM, or Manchester output modulation.
• Four selectable baud rates, button-queue information, and low-battery indication.
• On-chip EEPROM, tuned oscillator, LED output, and ASK/FSK PLL control.

Microchip's SM suffix specifies an eight-lead plastic SOIC with a nominal 208 mil molded-body width. The catalog lists 8-SOIC at approximately 5.30 mm width. Use the manufacturer drawing to confirm land pattern, overall width, and pin-1 orientation; do not interchange with the through-hole P variant or a narrow-body SOIC.

Layout checks

• Match the 208 mil body drawing to the PCB footprint.
• Follow the eight-pin top-view numbering.
• Place supply decoupling close to VDD and VSS.

The image is illustrative; exact dimensions come from the manufacturer package drawing.

Microchip DS41109D top-view assignment:

Multiplexed behavior depends on configuration; verify before wiring.

The ordering table and errata use different industrial lower-temperature values; obtain manufacturer confirmation for the exact operating qualification.

HCS365/P is a through-hole package and is not footprint-compatible with SM. Compare package, actual qualified temperature, modulation, timing, serial and key provisioning, seed behavior, and receiver synchronization before selecting an alternative. No unverified internal product link is provided.

Microchip DS41109D documents the encoder architecture, pin diagram, operating conditions, SM SOIC outline, and product identification system. Microchip errata DS80136A explicitly corrects the industrial lower-temperature condition in the DC and AC characteristics tables from −40 °C to −20 °C.

Verify the exact HCS365-I/SM order code, wide-body SOIC marking, lot traceability, and temperature qualification. Protect keys and seed values during programming and test the provisioned transmitter against the intended receiver.

Resolve the temperature discrepancy against Microchip DS80136A and current controlled documentation before release. Verify the SM footprint, pinout, receiver compatibility, modulation, low-battery threshold, timing, and cryptographic provisioning.