Product Overview
The PIC16F636-I is a 14-pin, 8-bit Flash-based CMOS microcontroller from Microchip Technology featuring a KEELOQ-compatible hardware cryptographic module. Based on the Mid-Range PIC architecture with 35 instructions and an 8-level deep hardware stack, it offers 3.5KB (2K x 14 words) of Flash program memory, 128 bytes of RAM, and 256 bytes of data EEPROM. Operating at up to 20 MHz with a 200 ns instruction cycle, this MCU integrates a precision 8 MHz internal oscillator, two analog comparators, and the unique KEELOQ cryptographic engine for secure authentication applications. With its nanoWatt Technology providing ultra-low power consumption and Programmable Low-Voltage Detect (PLVD), the PIC16F636 is ideal for keyless entry systems, remote controls, security tokens, and other authentication-based applications requiring hardware encryption.
Key Specifications
| Core Architecture | 8-bit PIC (Mid-Range Core) |
| Program Memory | 3.5KB Flash (2K x 14 words) |
| RAM | 128 bytes |
| Data EEPROM | 256 bytes |
| Maximum Speed | 20 MHz (5 MIPS) |
| Operating Voltage | 2.0V to 5.5V |
| I/O Pins | 12 |
| ADC | None |
| Comparators | 2 |
| Timers | 1 x 8-bit (TMR0) + 1 x 16-bit (TMR1) |
| Crypto Module | KEELOQ-compatible hardware encryptor |
| Communication | SPI |
| Internal Oscillator | 8 MHz (±1% factory calibrated) |
| Stack Levels | 8 |
| Operating Temperature | -40°C to +85°C (Industrial) |
| Package | 14-pin PDIP / SOIC / TSSOP / QFN |
Features
- Mid-Range PIC architecture with 35 single-cycle instructions and 8-level stack
- KEELOQ-compatible hardware cryptographic module for secure authentication
- Precision internal oscillator: 8 MHz factory calibrated to ±1%
- Software selectable frequency range: 8 MHz to 125 kHz
- Two analog comparators with programmable on-chip voltage reference (CVREF)
- 256 bytes of data EEPROM for secure key storage
- Programmable Low-Voltage Detect (PLVD) for brown-out protection
- nanoWatt Technology for ultra-low power consumption
- Ultra Low-Power Wake-up (ULPW) on pin change
- SPI serial communication port
- Enhanced Timer1 with external gate and low-power oscillator option
- Power-on Reset (POR), Power-up Timer (PWRT), Oscillator Start-up Timer (OST)
- Brown-out Reset (BOR) with software control option
- Enhanced Watchdog Timer (WDT) with on-chip RC oscillator
- In-Circuit Serial Programming (ICSP) via two pins
- Programmable code protection for program and data memory security
Applications
- Keyless entry systems (RKE/PKE)
- Remote controls with rolling code encryption
- Security tokens and authentication devices
- Access control systems
- Battery-powered secure remote sensors
- Automotive immobilizer systems
- Garage door openers with security features