PIC12F508-I/SN - 8-bit 4MHz MCU 768B Flash 8-SOIC | Microchip
MPN: PIC12F508-I/SN ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $0.62 | $0.62 |
| 10 | $0.55 | $5.50 |
| 100 | $0.47 | $47.00 |
| 500 | $0.41 | $205.00 |
| 1,000 | $0.36 | $360.00 |
| 3,000 | $0.31 | $930.00 |
PIC12F508-I/SN Overview
A microcontroller (MCU) is a single-chip computer integrating a CPU core, program memory (Flash/ROM), data memory (RAM), peripherals, and I/O on one die. The PIC12F508 belongs to the baseline PIC10/12/16 family - a subcategory of 8-bit microcontrollers optimized for low pin-count, low-cost, deterministic control tasks where an M-class ARM Cortex-M0 part would be overkill. Within the embedded hierarchy it sits between simple logic ICs (timers, gate drivers) and higher-end 32-bit MCUs, often replacing discrete logic plus a small EEPROM in space-constrained assemblies.
Key features of this part include an internal 4MHz RC oscillator (no external crystal required), one 8-bit Timer0 with programmable prescaler, a watchdog timer with on-chip RC oscillator for reliable reset, in-circuit serial programming (ICSP) via GP0/GP1, and on-chip in-circuit emulation support. The wide VDD range of 2.0V to 5.5V allows direct operation from 2xAA cells, single-cell Li-ion, or 3.3V/5V regulated rails. Six I/O pins each source/sink up to 25 mA, sufficient to drive LEDs, small relays, and logic buffers directly without external transistors.
The PIC12F508 architecture uses a Harvard RISC core with a single accumulator (W register) and 32-byte file-register SRAM, executing most instructions in a single 1us instruction cycle at 4MHz. The 12-bit instruction word eliminates unused upper bits, simplifying decoder logic and keeping silicon area minimal, which is why baseline PICs are consistently priced below 8-bit competitors. Brown-out detect and power-on reset are integrated.
Typical applications include low-cost consumer appliance controls, LED blinkers and decorative lighting drivers, PIR motion-sensor trigger boards, simple PWM fan or buzzer controllers, replacement of 555-timer + logic-gate circuits, and battery-powered remote keyfob transmitters. Its tiny 8-SOIC footprint and sub-$0.50 price point make it a go-to MCU for sub-100-node production runs.
Design tip: use GP0/GP1 for ICSP - reserve these two pins even in production PCB layouts so the firmware can be re-flashed without rework. Add a 100nF decoupling cap directly across VDD/VSS (pin 1 and pin 8), keep traces short, and route MCLR with its pull-up within 25 mm of pin 4 to avoid spurious resets in noisy environments.
This page synthesizes distributor pricing snapshots, verified drop-in alternatives in the same 8-SOIC package, and engineering design notes not found in the standalone datasheet - giving procurement and design engineers an at-a-glance view of supply, fit, and form.
Drop-in alternatives for PIC12F508-I/SN — 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 PIC12F508-I/SN (same form factor and footprint) — differing in Package, Timers, Maximum CPU Speed, Core Architecture, Data EEPROM.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PIC12F509-I/SN
✅ Drop-In✓ In Stock
$0.71 / Unit
View Datasheet →PIC12F508-E/SN
✅ Drop-In✓ In Stock
$0.62 / Unit
View Datasheet →PIC12F508T-I/SN
✅ Drop-In📋 Reference alternative (not in catalog)
PIC12F508-I/SNVAO
✅ Drop-In📋 Reference alternative (not in catalog)
PIC12F508T-E/SN
✅ Drop-In✓ In Stock
$0.48 / Unit
View Datasheet →PIC12F1501-E/SN
✅ Drop-In✓ In Stock
$0.58 / Unit
View Datasheet →PIC12F508-I/SN Maximum Ratings & Electrical Characteristics
| Core | PIC 8-bit RISC (Harvard) |
| Program Memory Type | Flash |
| Program Memory Size | 768 B (512 x 12 words) |
| RAM Size | 25 B |
| EEPROM Size | None |
| Maximum CPU Speed | 4 MHz (1 us instruction cycle) |
| I/O Pins | 6 |
| Timers | 1 x 8-bit (Timer0) |
| Watchdog Timer | Yes (independent on-chip RC oscillator) |
| ADC | None |
| ICSP (In-Circuit Serial Programming) | Yes (via GP0/GP1) |
| Supply Voltage (VDD) | 2.0 V to 5.5 V |
| Operating Temperature | -40 C to +85 C (Industrial) |
| I/O Pin Source/Sink Current | 25 mA per pin |
| Package | 8-SOIC (SN, 3.90 mm body) |
| Mounting Type | Surface Mount |
| MSL Level | 1 |
| RoHS Status | Compliant |
| Brown-out Reset | Yes (integrated) |
| Instruction Set Width | 12-bit |
PIC12F508-I/SN Pin Configuration
| Pin 1 | VDD — Positive supply voltage (2.0 V to 5.5 V) |
| Pin 2 | GP5/OSC1/CLKIN — GPIO 5 / Timer0 clock input / external oscillator input |
| Pin 3 | GP4/OSC2 — GPIO 4 / oscillator output |
| Pin 4 | GP3/MCLR (input only) — GPIO 3 (input only) / Master Clear reset, active-low |
| Pin 5 | GP2/T0CKI — GPIO 2 / Timer0 clock input |
| Pin 6 | GP1/ICSPCLK — GPIO 1 / ICSP clock |
| Pin 7 | GP0/ICSPDAT — GPIO 0 / ICSP data |
| Pin 8 | VSS — Ground reference |
Typical Applications
PIC12F508-I/SN is suitable for 6 applications: PIR Motion Sensor Trigger Board, Battery-Powered Remote Keyfob Transmitter, LED Blinker and Decorative Lighting Driver, 555-Timer Replacement and Discrete Logic Substitute, Small Appliance Control Board (Coffee Maker, Humidifier), Industrial Sensor Interface Front-End.
PIR Motion Sensor Trigger Board
The PIC12F508-I/SN is the canonical MCU for PIR motion-sensor trigger boards in security lighting and alarm pre-processing. Its 6 GPIO are sufficient to read a PIR analog front-end (one ADC-free comparator input), drive a relay or TRIAC output, blink a status LED, and listen to a manual override button. The 4 MHz internal oscillator eliminates an external resonator, and 2.0-5.5 V VDD lets the board run from a 3.3 V regulator off mains or a single 18650 cell. The 25 mA per-pin drive directly switches the LED and relay coil driver, and 768 B Flash fits the typical motion detection state machine plus EEPROM-emulated settings. Watchdog timer with independent RC handles brown-out and watchdog resets in unattended installations.
Recommended
Battery-Powered Remote Keyfob Transmitter
For sub-1 GHz OOK/FSK keyfob transmitters, the PIC12F508-I/SN delivers deterministic button-debounce, rolling-code bit-banging, and Sleep-mode duty cycling at price points below 8-bit competitors. At 4 MHz, a single instruction cycle of 1 us lets the firmware read up to 4 buttons, generate a 32-bit rolling code sequence, and key a SAW-resonator-based TX stage - all within 768 B Flash. Sleep current under 1 uA with watchdog disabled yields 5+ year shelf life on a CR2032 coin cell. The industrial -40C to +85C range covers automotive cabin conditions. ICSP via GP0/GP1 enables in-circuit programming on the final PCB before conformal coating.
Recommended
LED Blinker and Decorative Lighting Driver
Decorative LED strings, holiday lights, and chaser effects rely on the PIC12F508-I/SN's PWM-via-software flexibility plus its 6 GPIO that each source or sink 25 mA - enough to drive 5 V LEDs through 220 ohm resistors directly without transistors. The 4 MHz instruction rate supports multi-channel chase patterns, fade tables, and music-sync blink routines within the 768 B Flash budget. The 2.0-5.5 V supply accepts USB-powered, battery, or 12 V automotive (via small LDO) inputs. Brown-out reset prevents partial-program corruption during brown-outs. The tiny 8-SOIC footprint allows embedding inside miniature lamp housings or inline cord modules.
Recommended
555-Timer Replacement and Discrete Logic Substitute
Designers replacing legacy 555-timer plus discrete-logic circuits with a single PIC12F508-I/SN gain programmability, tighter timing accuracy, and one-BOM-line consolidation. The 4 MHz internal oscillator replaces RC timing networks with crystal-stability timing without external components, while 6 GPIO replace multiple gates and inverters. The MCU's 1 us instruction cycle generates frequencies from sub-Hz to hundreds of kHz with software precision, eliminating trim-pot adjustments. Industrial -40C to +85C range matches 555-grade environments, and the 25 mA I/O drive matches legacy TTL/CMOS logic outputs directly.
Recommended
Small Appliance Control Board (Coffee Maker, Humidifier)
Compact consumer appliances - coffee makers, humidifiers, aroma diffusers - use the PIC12F508-I/SN to replace electromechanical timers and cam switches with silent, programmable logic. The MCU's 6 GPIO handle button input, LED indicators, buzzer PWM, triac gate drive for heater element, and water-level sense. At $0.36 per unit in 1k quantities, the BOM cost beats discrete-logic alternatives. The 2.0-5.5 V supply accepts a small capacitive-dropper-derived 5 V rail directly from mains. Flash-based firmware supports late-stage feature updates and SKU differentiation through ICSP without hardware rework, useful for managing regional variants.
Recommended
Industrial Sensor Interface Front-End
Industrial binary sensor interface boards (limit switches, proximity sensors, photoelectric eyes) use the PIC12F508-I/SN as a debouncer, signal conditioner, and protocol translator. The 6 GPIO accept up to 4 sensor inputs, drive indicator LEDs, and bit-bang a simple UART or one-wire interface back to a master controller. The wide 2.0-5.5 V VDD accepts 24 V industrial bus power (after LDO), and -40C to +85C operation covers factory floor environments. The 768 B Flash fits debounce algorithms plus a simple LIN or Modbus-compatible framing layer. Watchdog timer with on-chip RC oscillator ensures autonomous recovery from EMI-induced lockups on long cable runs.
Recommended
Recommended Products Summary
Engineering reference data for PIC12F508-I/SN — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC12F509-I/SN | PIC12F508-E/SN | PIC12F508T-I/SN | PIC12F508-I/SNVAO | PIC12F1501-E/SN |
|---|---|---|---|---|---|---|
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Package | 8-SOIC (SN) | 8-SOIC (SN) - same | 8-SOIC (SN) - same | 8-SOIC (SN) - same | 8-SOIC (SN) - same | 8-SOIC (SN) - same |
| Program Memory (Flash) | 768 B | 1.5 KB | 768 B (same) | 768 B (same) | 768 B (same) | 1.75 KB |
| RAM | 25 B | 41 B | 25 B (same) | 25 B (same) | 25 B (same) | 64 B |
| I/O Pins | 6 | 6 (same) | 6 (same) | 6 (same) | 6 (same) | 6 (same) |
| Operating Temperature | -40C to +85C (Industrial) | -40C to +85C (same) | -40C to +125C (Extended) | -40C to +85C (same) | -40C to +125C (Automotive) | -40C to +125C (Extended) |
| ADC | None | None | None | None | None | 10-bit ADC |
| AEC-Q100 Qualified | No | No | No | No | Yes (VAO suffix) | No |
Key Differentiators
- Smallest pin-count Flash MCU in the PIC12 family with internal 4 MHz oscillator (vs PIC12F509-I/SN)
- Industrial temperature range standard, with extended and automotive grades available (vs PIC12F508-E/SN)
- No external crystal required - 2.0-5.5 V single-supply operation (vs PIC12F1501-E/SN)
Design Notes
Place a 100 nF decoupling capacitor within 5 mm of pins 1 (VDD) and 8 (VSS), with the ground lead going directly to the VSS pin via a short, wide trace. For noisy environments, add a 10 uF bulk capacitor near the VDD pin. Keep the ICSP traces (GP0/GP1, pin 6 and pin 7) short and route them to a 6-pin header on the PCB edge to retain in-circuit programming access in production boards.
The MCLR pin (pin 4) requires a pull-up resistor to VDD (typically 10 kohm) to prevent spurious resets. In high-noise environments, add a 100 nF capacitor from MCLR to VSS as an RC debounce (10 kohm * 100 nF = 1 ms time constant). Brown-out reset (BOR) is factory-trimmed; verify your application's minimum operating voltage (typically 2.0 V) is above the BOR threshold by checking datasheet 41236E electrical characteristics.
Do not exceed 25 mA source or sink per GPIO pin, and do not exceed 200 mA total package dissipation across all I/O simultaneously - per datasheet 41236E absolute maximum ratings. GP3 (pin 4) is input-only; configuring it as an output in firmware has no effect and can confuse code review. Reserve GP0 and GP1 for ICSP; if your design must use them as GPIO, plan for a 6-pin programming header accessible without rework.
Compliance Information
RoHS and REACH compliant per Microchip product page. The -I/SN variant is not AEC-Q100 qualified - choose the /SNVAO suffix variant for automotive applications.
