PIC16F636-E/P - 8-bit Flash MCU, 3.5KB, 12 I/O | Microchip
MPN: PIC16F636-E/P ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $2.75 | $2.75 |
| 10 | $2.45 | $24.50 |
| 100 | $2.1 | $210.00 |
| 500 | $1.85 | $925.00 |
| 1,000 | $1.65 | $1,650.00 |
PIC16F636-E/P Overview
A microcontroller (MCU) is a single-chip computer that integrates a CPU core, non-volatile program memory, working RAM, peripherals and I/O on one die. Within the broader taxonomy, the PIC16F636 belongs to the mid-range PIC16 family of 8-bit microcontrollers (RISC architecture), which itself sits under the 8-bit MCU hierarchy (8-bit MCU -> microcontroller -> embedded processor -> semiconductor). The mid-range core delivers deterministic single-cycle instruction execution and a compact 35-instruction set, allowing engineers to maintain code portability across the PIC16F-family while adding cryptographic, analog and timing peripherals.
Key features of the PIC16F636 include 12 digital I/O pins, two analog comparators with programmable on-chip reference, a KeeLoq-compatible hardware cryptographic peripheral for secure remote-keyless-entry (RKE) transmitters, a programmable Low-Voltage Detect (PLVD) module, an Enhanced Universal Synchronous/Asynchronous Receiver/Transmitter (EUSART) and a Capture/Compare/PWM (CCP) module. Internal 8 MHz and 31 kHz oscillators plus an external oscillator option give the designer flexibility between low power and accurate timing. The device supports In-Circuit Serial Programming (ICSP) for in-field firmware updates and retains MPLAB ICD debugging compatibility across the family.
Typical applications include automotive RKE transmitters and tire-pressure monitor encoders, security alarm keyfobs, wireless sensor transmitters, low-cost industrial control modules, and consumer white-goods user-interface boards. Its combination of cryptographic hardware and a small 14-pin footprint makes it especially common in battery-powered remote controls where PCB real estate is at a premium and security of the rolling code is mandatory.
When designing with the PIC16F636, allocate one decoupling 100 nF ceramic capacitor adjacent to each VDD/VSS pin pair, route the MCLR pin through a 10 kohm pull-up for normal operation, and observe the maximum 20 MHz clock with a 5 V supply. EEPROM endurance is 100,000 erase/write cycles typical, so use it for infrequently-updated parameters such as calibration constants or rolling-code counters rather than high-write-rate logs.
This page synthesizes distributor pricing and inventory, drop-in same-package alternatives, and practical design notes that complement the manufacturer datasheet to help engineers compare the PIC16F636-E/P against pin-compatible PIC16F630/PIC16F631 family members and PIC12F/PIC10F migrators.
Drop-in alternatives for PIC16F636-E/P — same package, pin-to-pin compatible. Different-package parts requiring PCB rework are excluded.
Variants in this series
Same-series models that are drop-in compatible with PIC16F636-E/P (same form factor and footprint) — differing in Package, Timers, Operating Temperature, Internal Oscillator, RoHS Status.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PIC16F636-I/P
✅ Drop-In✓ In Stock
$1.58 / Unit
View Datasheet →PIC16F630-E/P
✅ Drop-In✓ In Stock
$1.22 / Unit
View Datasheet →PIC16F631-E/P
✅ Drop-In✓ In Stock
$1.29 / Unit
View Datasheet →PIC16F616-E/P
✅ Drop-In✓ In Stock
$1.02 / Unit
View Datasheet →PIC16F610-E/P
✅ Drop-In✓ In Stock
$0.83 / Unit
View Datasheet →PIC12F1840-I/P
✅ Drop-In✓ In Stock
$0.85 / Unit
View Datasheet →PIC16F636-E/P Maximum Ratings & Electrical Characteristics
| Core | PIC16 mid-range 8-bit RISC |
| Program Memory Type | Flash |
| Program Memory Size | 3.5 KB (2K x 14 words) |
| RAM | 128 bytes |
| EEPROM Data Memory | 256 bytes |
| Maximum CPU Frequency | 20 MHz |
| Instruction Cycle | 200 ns |
| Supply Voltage (VDD) | 4.5 V to 5.5 V |
| I/O Pins | 12 |
| Analog Comparators | 2 (with programmable reference) |
| Communication | EUSART |
| CCP Module | 1 (Capture/Compare/PWM) |
| PLVD (Programmable Low-Voltage Detect) | Yes |
| Cryptographic Peripheral | KeeLoq-compatible hardware encoder |
| Internal Oscillator | 8 MHz and 31 kHz |
| Package | 14-pin PDIP (300 mil, through-hole) |
| Operating Temperature | -40 C to +125 C (extended, "E") |
| ICSP / In-Circuit Debug | Yes (MPLAB ICD compatible) |
| RoHS Status | Compliant (lead-free) |
PIC16F636-E/P Pin Configuration
| Pin 1 | VDD — Positive supply voltage (4.5 V to 5.5 V) |
| Pin 2 | RA5/T1CKI/OSC1/CLKIN — Digital I/O / Timer1 clock input / OSC1 / external clock input |
| Pin 3 | RA4/AN3/T1G/OSC2/CLKOUT — Digital I/O / analog input / Timer1 gate / OSC2 / clock output |
| Pin 4 | RA3/MCLR/VPP — Digital input / Master Clear (reset, active low) / programming voltage |
| Pin 5 | RC5 — Digital I/O |
| Pin 6 | RC4 — Digital I/O |
| Pin 7 | RC3 — Digital I/O |
| Pin 8 | RC2 — Digital I/O |
| Pin 9 | RC1 — Digital I/O |
| Pin 10 | RC0 — Digital I/O |
| Pin 11 | RB7/ICDAT/ICSPCLK — Digital I/O / ICD data / ICSP clock |
| Pin 12 | RB6/ICCK/ICSPDAT — Digital I/O / ICD clock / ICSP data |
| Pin 13 | RB5 — Digital I/O |
| Pin 14 | VSS — Ground reference |
Typical Applications
PIC16F636-E/P is suitable for 6 applications: Automotive Remote Keyless Entry (RKE) Transmitter, Wireless Security Alarm Keyfob / Sensor Transmitter, Tire Pressure Monitoring System (TPMS) Sensor Encoder, Industrial Control Module (Relay/Opto-Isolated I/O), Consumer Appliance User-Interface Board, Low-Cost Sensor Node / IoT Edge Transmitter.
Automotive Remote Keyless Entry (RKE) Transmitter
The PIC16F636-E/P is purpose-built for battery-powered automotive RKE keyfobs thanks to its integrated KeeLoq-compatible hardware cryptographic encoder, which performs rolling-code encryption in hardware without external security ICs. Its 4.5 V to 5.5 V VDD range matches a single CR2032 or two CR2016 cells with regulation, and the 20 MHz mid-range core gives enough throughput for button debounce, transmit framing and EEPROM-backed counter management. The 14-pin PDIP footprint keeps the PCB small enough to fit inside a standard keyfob enclosure, while the extended -40 C to +125 C temperature grade survives glove-box and dashboard thermal cycling. Power consumption benefits from the internal 31 kHz LF oscillator and NanoWatt sleep modes, giving months of standby life on a coin cell. Together, the KeeLoq encoder, EUSART for RF link and 256-byte EEPROM for non-volatile counter storage make the PIC16F636-E/P the canonical Microchip part for this application class.
Recommended
Wireless Security Alarm Keyfob / Sensor Transmitter
For wireless security alarm keyfobs and PIR/sensor transmitters, the PIC16F636-E/P provides the 128-byte RAM and 3.5 KB Flash needed to drive state machines, encode RF packets, and manage pairing sequences without an external companion IC. The two on-chip analog comparators with programmable voltage reference enable direct connection to a battery-voltage divider for low-battery detection via PLVD, replacing an external supervisor. The 12 GPIO pins can be allocated to two or three push-buttons, a learn-mode jumper, an LED driver and the RF transceiver's data/enable lines, all in the same 14-pin PDIP. NanoWatt technology lets the device drop to microamp-level sleep currents between transmissions, and the EUSART directly drives sub-GHz transceivers in OOK/FSK modes common in 315/433/868 MHz ISM bands. Its extended temperature grade ensures reliable operation in unheated garages and outdoor enclosures.
Recommended
Tire Pressure Monitoring System (TPMS) Sensor Encoder
In automotive Tire Pressure Monitoring System sensor encoders, the PIC16F636-E/P executes the application firmware, monitors the pressure-sensor front-end via its two analog comparators, and manages the RF transmitter timing through the CCP PWM module. Its 20 MHz instruction rate is sufficient to read the comparator thresholds, apply software filtering, and orchestrate UHF transmit frames inside the 100 ms wake windows typical of TPMS duty cycles. The 256-byte EEPROM stores the unique transmitter ID and pressure calibration coefficients for the lifetime of the sensor module, while the PLVD module issues a low-battery warning as the coin cell decays. The 14-pin PDIP footprint is small enough to fit inside the valve-stem sensor housing, and the -40 C to +125 C extended range covers under-tire thermal stress. Industrial-grade KeeLoq encoder support also allows encrypted TPMS variants for premium OEM programs.
Recommended
Industrial Control Module (Relay/Opto-Isolated I/O)
The PIC16F636-E/P fits compact industrial control modules where 12 GPIO pins drive relay coils, optocouplers, status LEDs and a serial diagnostic bus. Its 20 MHz mid-range core, 3.5 KB Flash and 128-byte RAM are enough to run a Modbus-RTU slave over the EUSART or a half-duplex RS-485 link, while the 256-byte EEPROM retains calibration setpoints and node addresses across power cycles. The PLVD module provides deterministic brown-out behavior on 24 V->5 V industrial rails, an important feature for IEC 61131-2 compliant equipment. Its extended -40 C to +125 C range covers outdoor cabinet and factory-floor temperatures. The 14-pin PDIP package remains popular for through-hole industrial designs because it tolerates conformal coating and mechanical stress better than fine-pitch SMD parts.
Recommended
Consumer Appliance User-Interface Board
In consumer white-goods UI boards (washing machines, dishwashers, microwave ovens), the PIC16F636-E/P scans a matrix keypad or capacitive touch front-end, drives a 7-segment or character LCD, and communicates with the main appliance controller over UART. The on-chip EUSART links directly to the appliance MCU without an external transceiver, while the 3.5 KB Flash supports look-up tables for button de-bounce, child-lock state and energy-saver profiles. The two analog comparators monitor line-frequency zero-crossing for triac dimming and detect door-open switches. The extended temperature grade covers oven-cabinet environments, and the through-hole 14-pin PDIP package is favored by appliance OEMs for hand-soldered or wave-soldered production lines. Designers can drop down to PIC16F630-E/P for cost-sensitive UI boards that do not need the comparator or KeeLoq hardware.
Recommended
Low-Cost Sensor Node / IoT Edge Transmitter
For ultra-low-cost sensor nodes that transmit small packets over sub-GHz ISM links, the PIC16F636-E/P runs the sensor read loop, encodes the data, and handles RF timing while drawing microamp currents in sleep. The two analog comparators with programmable reference support battery-voltage and threshold-crossing detection without an ADC, which is sufficient for thermistor-style sensors, PIR motion detectors and magnetic-reed switch debouncing. Its 12 GPIO can drive an SPI temperature/humidity sensor, an LED status indicator and the RF enable line, all inside the 14-pin PDIP. The 256-byte EEPROM preserves device identity and last-known state across power cycles, and the KeeLoq-compatible crypto peripheral can be repurposed for lightweight authentication on edge nodes. Combined with NanoWatt sleep, a CR2032 can power a transmit-every-30-seconds node for several years.
Recommended
Recommended Products Summary
Engineering reference data for PIC16F636-E/P — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC16F636-I/P | PIC16F630-E/P | PIC16F631-E/P | PIC16F616-E/P | PIC16F610-E/P |
|---|---|---|---|---|---|---|
| Package | PDIP-14 (300 mil) | PDIP-14 (300 mil) - same | PDIP-14 (300 mil) - same | PDIP-14 (300 mil) - same | PDIP-14 (300 mil) - same | PDIP-14 (300 mil) - same |
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Program Memory | 3.5 KB Flash | 3.5 KB Flash | 3.5 KB Flash | 4 KB Flash | 3.5 KB Flash | 2 KB Flash |
| RAM | 128 bytes | 128 bytes | 128 bytes | 128 bytes | 128 bytes | 64 bytes |
| Analog Comparators | 2 | 2 | 0 | 2 | 2 | 2 |
| KeeLoq Crypto Encoder | Yes | Yes | No | No | No | No |
| PLVD Module | Yes | Yes | No | No | No | No |
| Operating Temperature | -40 C to +125 C (E) | -40 C to +85 C (I) | -40 C to +125 C (E) | -40 C to +125 C (E) | -40 C to +125 C (E) | -40 C to +125 C (E) |
Key Differentiators
- Integrated KeeLoq-compatible hardware cryptographic encoder (vs PIC16F630-E/P)
- Two analog comparators with programmable on-chip reference (vs PIC16F630-E/P)
- Programmable Low-Voltage Detect (PLVD) module (vs PIC16F631-E/P)
- Extended -40 C to +125 C operating temperature grade (vs PIC16F636-I/P)
Design Notes
Decouple VDD (pin 1) and VSS (pin 14) with a 100 nF ceramic capacitor placed within 5 mm of the supply pins. For battery-powered RKE keyfobs powered directly from a CR2032 cell, add a 10 uF bulk capacitor in parallel to ride out RF transmit current spikes; the PIC16F636-E/P draws only microamps in sleep but burst current during EUSART/CCP-driven transmit can briefly exceed 10 mA. Always include the standard 10 kohm pull-up on MCLR (pin 4) to keep the device out of reset during noisy supply events.
Route the ICSP lines RB6/ICCK (pin 12) and RB7/ICDAT (pin 11) with a 5-10 kohm series isolation resistor on each line to the programming header so production programming can be done with the rest of the circuit connected. Keep the OSC1/OSC2 traces short and surround them with a ground pour if an external crystal is used; in HS-mode the 20 MHz signal has fast edges and is susceptible to capacitive coupling into adjacent analog comparator inputs. The 14-pin PDIP package permits wide trace routing, which is helpful for hand-rework and educational designs.
Do not exceed the 5.5 V absolute-maximum rating on VDD; the PIC16F636-E/P is not a 3.3 V part and will erase Flash unreliably below 4.5 V. When migrating code from PIC16F630 to PIC16F636, remember that the extra comparator registers (CMCON0/CMCON1) and CVR module must be initialized correctly or the comparator outputs may interfere with the RB port digital logic. Estimated: at 20 MHz with 5 V VDD, supply current is approximately 8-10 mA active; use the NanoWatt sleep modes and the internal 31 kHz LF oscillator for battery applications to drop quiescent current below 1 uA.
The internal comparators on the PIC16F636-E/P have a maximum toggle time on the order of hundreds of nanoseconds and are well-suited to low-frequency battery-voltage detection rather than high-speed analog signal conditioning. For RF applications, place the comparator reference voltage divider near the VDD pin and bypass with 100 nF to avoid ground bounce during EUSART activity. When using the CCP module for PWM, keep the PWM output trace short and add a 100 ohm series resistor if the trace exceeds 25 mm to reduce ringing on the gate of the driven FET.
Compliance Information
RoHS-compliant lead-free PDIP package per Microchip product page. Not formally AEC-Q100 qualified as a standalone MCU; PIC16F636 family is used inside many automotive RKE subsystems but the part itself is not listed on Microchip's automotive-grade catalog for this exact MPN.
