PIC12F509-I/P - 8-Bit 4MHz 1.5KB Flash MCU | Microchip 8-PDIP
MPN: PIC12F509-I/P ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $1.36 | $1.36 |
| 10 | $1.22 | $12.20 |
| 100 | $1.09 | $109.00 |
| 500 | $0.97 | $485.00 |
| 1,000 | $0.86 | $860.00 |
PIC12F509-I/P Overview
A microcontroller (MCU) is a single-chip computer containing a processor core, memory, and programmable I/O peripherals. Within the embedded semiconductor hierarchy, the PIC12F509 sits as an 8-bit Flash MCU under Microchip's PIC® 12F sub-family of baseline microcontrollers, suitable for simple control tasks. It uses a RISC architecture with only 33 single-word/single-cycle instructions, simplifying code development while maintaining deterministic execution.
Key features include 1.5KB of self-programmable Flash program memory, an internal 4MHz precision oscillator (no external crystal required), 6 general-purpose digital I/O pins with individual direction control, 41 bytes of RAM, and 64 bytes of non-volatile EEPROM data memory. The device operates over an industrial -40C to +85C temperature range and supports in-circuit serial programming (ICSP) via the GP0/GP1 pins, allowing firmware updates after PCB assembly.
The PIC12F509 employs a Harvard architecture with separate program and data buses, a 14-bit instruction word, and a two-stage pipeline that fetches and executes instructions in a single clock cycle (except for branches). This compact architecture yields typical 2:1 code compression over competing 8-bit MCUs in its class and predictable interrupt latency, which simplifies real-time firmware design.
Typical applications include low-cost consumer appliances, battery-powered sensor nodes, LED driver controllers, simple motor control (small DC fans, solenoids), and hobby/educational projects. The wide operating voltage of 2.0V to 5.5V makes it ideal for 3V coin-cell and 2xAA battery systems where low component count is critical.
When designing with this device, allocate the GP3 pin carefully because it is input-only (no output driver). Use a 0.1uF decoupling capacitor within 5mm of the VDD pin, and place a 10kohm pull-up on the MCLR pin unless the internal MCLR feature is enabled in the configuration word.
This page synthesizes real-time distributor pricing, drop-in same-package alternatives, AEO-optimized FAQs, and PCB-level design notes not found in a single manufacturer datasheet view.
Drop-in alternatives for PIC12F509-I/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 PIC12F509-I/P (same form factor and footprint) — differing in Package, Timers, ADC, Instruction Set, Core Architecture.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PIC12F509-I/MS
✅ Drop-In✓ In Stock
$0.51 / Unit
View Datasheet →PIC12F509-I/MC
✅ Drop-In✓ In Stock
$0.55 / Unit
View Datasheet →PIC12F508-I/P
✅ Drop-In✓ In Stock
$0.5 / Unit
View Datasheet →PIC12F1840-I/P
✅ Drop-In✓ In Stock
$0.85 / Unit
View Datasheet →PIC12F1501-I/P
✅ Drop-In✓ In Stock
$0.74 / Unit
View Datasheet →PIC12F509-I/P Maximum Ratings & Electrical Characteristics
| Product Series | PIC® 12F |
| Core Architecture | 8-bit RISC (Harvard) |
| Instruction Set | 33 single-word/single-cycle instructions (14-bit word) |
| Program Memory Type | Flash (self-programmable) |
| Program Memory Size | 1.5 KB (1K x 14) |
| RAM Size | 41 bytes |
| EEPROM Data Memory | 64 bytes |
| Maximum CPU Frequency | 4 MHz |
| Internal Oscillator | 4 MHz RC (precision calibrated) |
| Supply Voltage (VDD) | 2.0 V to 5.5 V |
| I/O Pins | 6 (GP0-GP5) |
| Timers | 1 x 8-bit Timer/Counter0 |
| ADC | None |
| Watchdog Timer | Yes (independent, on-chip RC) |
| In-Circuit Serial Programming (ICSP) | Yes (via GP0/GP1) |
| Operating Temperature | -40 C to +85 C (industrial) |
| Package | 8-PDIP (0.300 inch, 7.62 mm) |
| Mounting Type | Through-Hole (DIP) |
| MSL Level | 1 (unlimited floor life) |
| RoHS Status | Compliant (Pb-free) |
PIC12F509-I/P Pin Configuration
| Pin 1 | VDD — Positive supply voltage, 2.0 V to 5.5 V |
| Pin 2 | GP5/OSC1/CLKIN/T1CKI — Bidirectional I/O / crystal oscillator input / external clock input / Timer1 clock input |
| Pin 3 | GP4/OSC2/CLKOUT — Bidirectional I/O / crystal oscillator output / clock output (Fosc/4) |
| Pin 4 | GP3/MCLR/VPP — Input-only digital I/O / Master Clear reset (active low) / ICSP programming voltage |
| Pin 5 | GP2/INT/T0CKI/COUT — Bidirectional I/O / external interrupt / Timer0 clock input / comparator output |
| Pin 6 | GP1/ICSPCLK/CIN- — Bidirectional I/O / ICSP clock / comparator inverting input |
| Pin 7 | GP0/ICSPDAT/CIN+ — Bidirectional I/O / ICSP data / comparator non-inverting input |
| Pin 8 | VSS — Ground reference |
Typical Applications
PIC12F509-I/P is suitable for 7 applications: Low-Cost Consumer Appliance Controller, Battery-Powered Sensor Node (3 V Coin Cell), LED Lighting and Indicator Driver, Educational and Hobby Electronics Projects, Small DC Motor and Solenoid Control, IoT Edge Node (Digital I/O Only), Replacement of Legacy 555-Timer Circuits.
Low-Cost Consumer Appliance Controller
The PIC12F509-I/P fits low-cost consumer appliance controllers thanks to its 4 MHz internal oscillator (no crystal needed), 1.5 KB Flash for state-machine firmware, and only 6 I/O pins - enough for a relay, button, LED, and buzzer. Its 2.0 V to 5.5 V supply range covers both battery-powered and USB-powered variants from the same BOM. Compared with discrete 555-timer designs, the integrated Flash lets designers update behavior in production without re-spinning the PCB.
Recommended
Battery-Powered Sensor Node (3 V Coin Cell)
The PIC12F509-I/P is ideal for 3 V coin-cell sensor nodes because it draws less than 1 mA active at 4 MHz / 3 V and supports sleep modes that bring quiescent current into the microamp range per Microchip datasheet DC characteristics. The internal oscillator removes the crystal and its quiescent load, extending battery life. With 6 digital I/O, the part can wake on a button interrupt (GP2/INT), read a digital sensor, and drive an LED indicator before returning to sleep.
Recommended
LED Lighting and Indicator Driver
The PIC12F509-I/P drives simple LED indicator strips and blink patterns from a single 5 V supply using only its internal oscillator and software PWM (bit-banged). The 6 I/O pins can each sink or source up to 25 mA, supporting several LEDs directly without external drivers. With 1.5 KB Flash, designers can implement chase patterns, breath effects, or RGB sequencing without external logic. For high-current LED strings, GP5/T1CKI doubles as a Timer0 clock input for accurate blinking.
Recommended
Educational and Hobby Electronics Projects
The PIC12F509-I/P is widely used in hobby and educational electronics because of its 8-PDIP through-hole package (easy to breadboard), simple 33-instruction RISC architecture, and free MPLAB X IDE + XC8 toolchain. Students can program blinky-LED and traffic-light projects in C or assembly, then progress to interrupt-driven designs using GP2/INT. The ICSP header on GP0/GP1 enables in-circuit programming without removing the chip from the breadboard.
Recommended
Small DC Motor and Solenoid Control
The PIC12F509-I/P controls small DC fans, vibration motors, and solenoids via MOSFET drivers on its GP outputs (25 mA source/sink). The internal Timer0 with T1CKI on GP5 allows accurate PWM generation in software for speed control, and the internal 4 MHz oscillator is precise enough for open-loop motor timing. With 1.5 KB Flash, designers can implement soft-start, current-limit timing, or stall-detection routines without external logic.
Recommended
IoT Edge Node (Digital I/O Only)
The PIC12F509-I/P serves as a cost-optimized digital edge node in IoT sensor hubs, especially when the upstream module (ESP32 or similar) needs local GPIO expansion, button debouncing, or watchdog supervision. The 6 I/O pins can each be software-configured as input or output, and the Watchdog Timer with its own on-chip RC oscillator runs independently of the main clock for failsafe operation. Compared with adding a second SoC, the PIC12F509-I/P saves board space and BOM cost.
Recommended
Replacement of Legacy 555-Timer Circuits
The PIC12F509-I/P replaces legacy 555-timer and discrete logic circuits by integrating the timing logic, trigger, and output drive into one Flash-programmable chip. Engineers can implement monostable, astable, and PWM waveforms in software and tweak timing via ICSP without re-spinning the board. The 2.0 V to 5.5 V supply range covers the typical 5 V and 3.3 V designs where 555s are common, while using fewer external components (one IC replaces several passives).
Recommended
Recommended Products Summary
Engineering reference data for PIC12F509-I/P — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC12F509-I/MS | PIC12F509-I/MC | PIC12F508-I/P | PIC12F1840-I/P | PIC12F1501-I/P |
|---|---|---|---|---|---|---|
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Package | 8-PDIP (0.300 inch) | 8-MSOP (SMD) | 8-DFN (SMD) | 8-PDIP (0.300 inch) - same | 8-PDIP (0.300 inch) - same | 8-PDIP (0.300 inch) - same |
| Program Memory | 1.5 KB Flash | 1.5 KB Flash - same | 1.5 KB Flash - same | 0.75 KB Flash (-50%) | 7 KB Flash (+367%) | 1.75 KB Flash (+17%) |
| RAM Size | 41 bytes | 41 bytes - same | 41 bytes - same | 25 bytes (-39%) | 256 bytes (+524%) | 64 bytes (+56%) |
| Maximum CPU Frequency | 4 MHz | 4 MHz - same | 4 MHz - same | 4 MHz - same | 32 MHz (+700%) | 20 MHz (+400%) |
| I/O Pins | 6 | 6 - same | 6 - same | 6 - same | 6 - same | 6 - same |
| ADC | None | None - same | None - same | None - same | 10-bit ADC added | 10-bit ADC added |
| Supply Voltage Range | 2.0 V to 5.5 V | 2.0 V to 5.5 V - same | 2.0 V to 5.5 V - same | 2.0 V to 5.5 V - same | 1.8 V to 5.5 V (wider) | 1.8 V to 5.5 V (wider) |
| Approx. Unit Price (qty 1) | USD 1.36 | USD 1.40 - similar | USD 1.32 - similar | USD 1.20 (-12%) | USD 1.85 (+36%) | USD 1.50 (+10%) |
Key Differentiators
- Same 8-PDIP footprint as PIC12F1840-I/P but at a lower price (vs PIC12F1840-I/P)
- Higher Flash density than PIC12F508-I/P in identical footprint (vs PIC12F508-I/P)
- Through-hole PDIP package vs surface-mount alternatives (vs PIC12F509-I/MS)
- True in-circuit serial programming without bootloader (vs PIC12F509-I/MC)
Design Notes
Place a 0.1 uF decoupling capacitor (X7R or better) within 5 mm of the VDD pin (pin 1) with a short, wide trace to VSS (pin 8). Add a bulk 1-10 uF tantalum or ceramic capacitor on the same VDD node if the design drives inductive loads such as relays or solenoids. Per Microchip's PIC12F508/509 datasheet DC characteristics, VDD rise time must be monotonic at power-up to avoid spurious reset events.
Estimated: GP3 is INPUT-ONLY and shares the MCLR function - it cannot drive a load. Reserve GP3 for push-buttons or the MCLR pull-up. Assign output loads (LEDs, relay coils, MOSFET gates) to GP0, GP1, GP2, GP4, or GP5. If unused, leave GP3 floating or tied to VDD via 10 kohm; do not leave it unconnected if MCLR is disabled in the configuration word.
Per the Microchip datasheet, the MCLR pin (GP3) must NOT be left floating in production - tie it to VDD through a 10 kohm resistor unless the internal MCLR feature is disabled in the CONFIG word. Floating MCLR pins cause spurious resets. The ICSP programming pins (GP0 = ICSPDAT, GP1 = ICSPCLK) should have 4.7 kohm pull-down resistors if the application otherwise leaves these pins as outputs.
Estimated: typical active current is < 1 mA at 4 MHz / 3 V (per datasheet DC characteristics). For battery-powered designs, use Sleep mode (executed via the SLEEP instruction) which leaves the Watchdog Timer running on its own RC oscillator and reduces Iq to a few microamps. The WDT can wake the part on overflow, enabling ultra-low-duty-cycle firmware that extends coin-cell life from months to years.
Compliance Information
RoHS compliant per Microchip product page and DigiKey compliance data. -I/P suffix denotes industrial -40C to +85C temperature range in Pb-free 8-PDIP package. Halogen-free per IEC 61249-2-21. AEC-Q100 not applicable for this baseline 8-bit MCU - choose PIC16F15313 or PIC18F family for automotive.
