Microchip Technology HCS370/P

The HCS370 creates a code-hopping transmission from a nonlinear encrypted hopping value, serial number, and button status. It is designed for remote keyless entry and related access-control transmitters. The `/P` suffix denotes a 14-lead, 300-mil plastic DIP; no `I` temperature prefix denotes the commercial 0 to +70 °C ordering grade in Microchip's product identification system. It must be programmed with the intended key, serial number, and configuration before system use.

• KEELOQ code-hopping encoder for remote keyless entry.
• 67-bit transmission format described in the Microchip data sheet.
• EEPROM storage for encryption key, serial number, and configuration.
• Multiple button inputs and support for a dual-encoder configuration.
• RF-enable, LED, shift, and step-related functions in the 14-pin pin diagram.
• Serial programming method detailed in Microchip's HCS370 programming specification.

Microchip identifies package code P as a 14-lead plastic dual in-line package with a 300-mil body. The local catalog lists 14-DIP (0.300 inch / 7.62 mm), matching the family package outline. The workbook registers 14-DIP, but its local `14-DIP.jpg` illustration is absent; use the manufacturer's dimensioned PDIP drawing for board design.

Assembly checks

• Verify pin-1 orientation and 300-mil row spacing.
• Confirm lead pitch and board hole size from the data sheet.
• Check device marking and selected temperature grade.

The 14-pin diagram identifies S0–S4 button inputs, SLEEP/S5, SHIFT, LED, DATA, RFEN, STEP, VIN, VDD, and VSS. Button inputs select transmitted status; DATA carries the encoded stream; RFEN can control the radio section. Programming uses defined pins and voltages from the separate Microchip programming specification. Follow the numbered PDIP top-view drawing rather than this summary when wiring.

Use the applicable manufacturer revision, errata, programming specification, and electrical test conditions for design limits.

HCS370/SL and /ST use different surface-mount footprints. HCS370-I/P has a different order temperature grade; do not assume identical temperature qualification. Confirm security configuration, code format, receiver synchronization, button mapping, pinout, supply, and package before substitution. No unverified internal alternative link is provided.

Microchip's HCS370 data sheet DS41111E defines the KEELOQ encoder, /P package, commercial ordering grade, pin functions, and electrical tables. The HCS370 programming specification DS41157D details serial programming. Errata DS80137A corrects an industrial-temperature condition in an earlier data-sheet table; this catalog `/P` code is the commercial grade, so no industrial lower-temperature claim is made here.

Verify exact `/P` marking, manufacturer traceability, package geometry, and configured cryptographic data. Protect programming secrets and validate interoperability with the intended decoder. A package photo is illustrative only and cannot establish electrical or security compatibility.

Before publication, restore and inspect the 14-DIP JPG and verify the rendered page. Before product use, review the latest Microchip data sheet and errata, program keys securely, confirm receiver synchronization and RF circuitry, and validate environmental and security requirements in the complete system.