PIC12C509A-04I/MF - 8-bit 4MHz OTP MCU, 1.5KB, 8-DFN | Microchip
MPN: PIC12C509A-04I/MF ✗ End of Life| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $1.92 | $1.92 |
| 10 | $1.73 | $17.30 |
| 100 | $1.42 | $142.00 |
| 500 | $1.18 | $590.00 |
| 1,000 | $0.99 | $990.00 |
PIC12C509A-04I/MF Overview
An 8-bit microcontroller (MCU) is a small computer-on-a-chip integrating a CPU, memory (ROM/Flash/OTP and RAM), I/O peripherals, and timers on a single die. The PIC12C5XX family belongs to the baseline PIC12C microcontrollers, sitting in Microchip's hierarchy of 8-bit MCU -> microcontroller -> embedded processor -> semiconductor. These parts target cost-sensitive, space-constrained embedded control applications where simple RISC instruction sets and ultra-low pin counts outweigh the need for large memories.
Key features include 33 single-word/single-cycle instructions, an 8-bit real-time clock/counter (TMR0) with programmable prescaler, Power-On Reset (POR), Device Reset Timer (DRT), Watchdog Timer (WDT) with its own on-chip RC oscillator, and programmable code protection. The internal 4 MHz RC oscillator eliminates external clock components, reducing BOM cost. The 8-bit instruction word and 12-bit opcode architecture provide deterministic execution for real-time control loops.
Typical applications include automotive body electronics, industrial control, appliance control, sensor signal conditioning, and low-end consumer devices. With only 5 I/O pins available after accounting for VDD/VSS and reset, the part is best suited to simple state machines, timing-based controllers, and glue-logic replacement. The DFN-S 6x5 mm surface-mount package suits reflow assembly on compact PCBs, and the 04 MHz speed grade balances instruction throughput against power consumption in always-on applications.
When designing with this device, ensure the MCLR pin is properly handled (it can be left open in many cases due to internal weak pull-up), and that the WDT is either enabled in software or disabled via configuration bits. The OTP memory means firmware must be fully validated before programming; use the PIC12C509A JW UV-erasable windowed version for prototype development. Five I/O pins (GP0-GP4 with GP3 only available as input) must be allocated carefully between user I/O and the optional oscillator/reset functions.
This page synthesizes distributor pricing, drop-in same-package alternatives, comparison data, and practical design notes for the PIC12C509A-04I/MF that are not consolidated on any single manufacturer or distributor page, helping engineers evaluate replacements and design trade-offs in one place.
Drop-in alternatives for PIC12C509A-04I/MF — 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 PIC12C509A-04I/MF (same form factor and footprint) — differing in Data EEPROM, Core Architecture, Program Memory Size, I/O Pins, Package.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PIC12C509A-04I/SM
✅ Drop-In✓ In Stock
$0.93 / Unit
View Datasheet →PIC12C509A-04I/SN
✅ Drop-In✓ In Stock
$0.92 / Unit
View Datasheet →PIC12C509A-04/SM
✅ Drop-In✓ In Stock
$0.99 / Unit
View Datasheet →PIC12C509A-04E/SM
✅ Drop-In✓ In Stock
$1.55 / Unit
View Datasheet →PIC12C509AT-04I/MF
✅ Drop-In📋 Reference alternative (not in catalog)
PIC12C509A-04I/MF Maximum Ratings & Electrical Characteristics
| Core Processor | PIC |
| Core Size | 8-bit |
| Clock Speed | 4 MHz |
| Instruction Cycle | 1 microsecond |
| Program Memory | 1.5 KB (1K x 12) OTP |
| RAM Size | 41 x 8 bytes |
| Data EEPROM | 0 bytes |
| I/O Pins | 5 (GP0-GP2, GP4-GP5; GP3 input only) |
| Number of Instructions | 33 |
| Timers | TMR0 (8-bit) with 8-bit programmable prescaler |
| Watchdog Timer | Yes, with dedicated on-chip RC oscillator |
| Power-On Reset | Yes (POR) |
| Device Reset Timer | Yes (DRT) |
| Code Protection | Programmable |
| Oscillator | Internal 4 MHz RC |
| Supply Voltage | 2.5 V to 5.5 V |
| Operating Temperature | -40C to +85C (Industrial) |
| Package | 8-DFN-S (6 x 5 mm) |
| Mounting Type | Surface Mount |
| RoHS Status | Compliant |
PIC12C509A-04I/MF Pin Configuration
| Pin 1 | VDD — Positive supply voltage (2.5V to 5.5V) |
| Pin 2 | GP5/OSC1 — General-purpose I/O or oscillator input |
| Pin 3 | GP4/OSC2 — General-purpose I/O or oscillator output |
| Pin 4 | GP3/MCLR — Input-only GPIO or Master Clear reset |
| Pin 5 | VSS — Ground reference |
| Pin 6 | GP0 — General-purpose I/O |
| Pin 7 | GP1 — General-purpose I/O |
| Pin 8 | GP2 — General-purpose I/O |
Typical Applications
PIC12C509A-04I/MF is suitable for 6 applications: Automotive Body Electronics, Appliance Control (Washing Machines, Dishwashers, Microwaves), Sensor Signal Conditioning and Simple Data Acquisition, Battery-Powered Remote Controls and Wireless Key Fobs, Industrial Control and Simple PLC Sub-Modules, Toy and Low-End Consumer Electronics.
Automotive Body Electronics
The PIC12C509A-04I/MF suits low-cost automotive body controllers (lamp drivers, wiper timers, simple sensor interfaces) where its -40C to +85C industrial temperature range, 4 MHz instruction throughput, and 1 microsecond per-instruction cycle meet real-time control needs. The internal 4 MHz RC oscillator eliminates the external crystal, reducing BOM and assembly cost. With 1.5KB OTP code space and 5 I/O pins, it fits single-function body controllers (e.g., sequential turn signal, dome-light delay) but is not suitable for AEC-Q100 qualified safety-critical modules. A typical circuit places the MCU between a 12V-to-5V regulator and the load FET, with GP0/GP1 driving N-channel MOSFETs for high-side switching and the WDT enabled for field reliability.
Recommended
Appliance Control (Washing Machines, Dishwashers, Microwaves)
In white goods and small appliances, the PIC12C509A-04I/MF is used for user-interface LED indicators, push-button debouncing, and timing control of pumps, valves, and buzzers. Its 33-instruction RISC core executes deterministic timing loops without an RTOS, while the 8-bit TMR0 with 8-bit prescaler supports 1 ms to 100 ms timing resolution needed for motor soft-start and pump cycle management. The 41-byte RAM is sufficient for state-machine control of 4-5 user inputs and 4-5 output drivers. A typical schematic uses GP3 as the panel button input, GP0/GP1 to drive TRIAC optocouplers, and the internal WDT to recover from AC-line brownouts.
Recommended
Sensor Signal Conditioning and Simple Data Acquisition
The PIC12C509A-04I/MF works well for low-frequency sensor front-ends that need digital filtering, threshold detection, and digital output. Although the part lacks an ADC, the comparator or external analog front-end can feed GP0/GP1 directly, and the TMR0 captures period or pulse-width measurements. With 1 microsecond per instruction, the 4 MHz core samples at up to 1 MSPS for short bursts, sufficient for 100 Hz to 1 kHz industrial sensors. The 8-pin DFN-S package (6x5 mm) is small enough for in-line sensor modules. The internal WDT and POR handle noisy industrial environments.
Recommended
Battery-Powered Remote Controls and Wireless Key Fobs
Low-power key fobs, garage door openers, and simple RF remote controls use the PIC12C509A-04I/MF to encode button presses via PWM or Manchester-encoded bit streams on a single GPIO. The 2.5V to 5.5V supply range supports 3V coin-cell or 2xAA operation, and the part's 1 microsecond instruction cycle generates accurate 38 kHz carrier frequencies for IR protocols or 433 MHz SAW-resonator sub-carriers. The internal WDT can wake the part from sleep on a button press, minimizing quiescent current. DFN-S 6x5 mm packaging suits miniaturized fob designs.
Recommended
Industrial Control and Simple PLC Sub-Modules
In industrial control panels, the PIC12C509A-04I/MF can be deployed as an auxiliary 8-bit sub-controller for status LED drivers, push-button scanners, and isolated digital I/O expansion where 5 GPIO pins are sufficient. The industrial -40C to +85C rating handles cabinet environments, and the WDT with its own on-chip RC oscillator provides recovery from ESD or supply glitches common on factory floors. The OTP memory can hold pre-validated ladder-logic emulation code, and the part's 33-instruction RISC core produces deterministic scan times for predictable control behavior. A typical application pairs the MCU with an MCP1700 5V LDO and digital optocouplers for 24V field-interface isolation.
Recommended
Toy and Low-End Consumer Electronics
Toys, educational electronics kits, and low-cost consumer products use the PIC12C509A-04I/MF for sound effect generation, motor PWM, LED pattern control, and simple I/O expansion. The 33-instruction RISC core is well documented in Microchip application notes (e.g., AN529) and easy for beginners to program. The 5 GPIO pins are sufficient for a 2-axis toy controller, a single-motor with direction logic, or a 5-LED Christmas decoration sequencer. The DFN-S 6x5 mm package is small enough for thin-profile toys, though hand-soldering requires hot air. PICkit programmers and MPLAB X IDE support the full PIC12C5XX family.
Recommended
Recommended Products Summary
Engineering reference data for PIC12C509A-04I/MF — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC12C509A-04I/SM | PIC12C509A-04I/SN | PIC12C509A-04/SM | PIC12C509A-04E/SM | PIC12C509AT-04I/MF |
|---|---|---|---|---|---|---|
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Package | 8-DFN-S (6x5 mm) | 8-SOIC (3.90 mm) - same 8-pin family | 8-SOIC (3.90 mm) - same 8-pin family | 8-SOIC (3.90 mm) - same 8-pin family | 8-SOIC (3.90 mm) - same 8-pin family | 8-DFN-S (6x5 mm) - identical |
| Core Processor | PIC 8-bit | PIC 8-bit | PIC 8-bit | PIC 8-bit | PIC 8-bit | PIC 8-bit |
| Clock Speed | 4 MHz | 4 MHz | 4 MHz | 4 MHz | 4 MHz | 4 MHz |
| Program Memory | 1.5 KB OTP | 1.5 KB OTP | 1.5 KB OTP | 1.5 KB OTP | 1.5 KB OTP | 1.5 KB OTP |
| RAM Size | 41 bytes | 41 bytes | 41 bytes | 41 bytes | 41 bytes | 41 bytes |
| Operating Temperature | -40C to +85C (Industrial) | -40C to +85C (Industrial) | -40C to +85C (Industrial) | 0C to +70C (Commercial) | -40C to +125C (Extended) | -40C to +85C (Industrial) |
| Lifecycle Status | Obsolete | Obsolete | Obsolete | Obsolete | Obsolete | Obsolete |
Key Differentiators
- 8-pin DFN-S (6x5 mm) for smallest PCB footprint in the PIC12C5XX baseline family (vs PIC12C509A-04I/SN)
- Industrial -40C to +85C operating temperature range (vs PIC12C509A-04/SM)
- Firmware and peripheral compatibility across the PIC12C5XX baseline family (vs PIC12C508A)
Design Notes
The PIC12C509A-04I/MF operates from 2.5V to 5.5V and draws approximately 2 mA active current at 4 MHz and 5V per the PIC12C5XX datasheet. For battery applications, use the SLEEP instruction (a 1 microsecond wake-up) and the internal WDT to wake periodically, reducing average current below 100 microamperes. A 0.1 microfarad ceramic bypass capacitor must be placed within 5 mm of the VDD pin per Microchip layout guidelines; adding a 10 microfarad bulk cap on the VDD rail is recommended for noisy industrial supplies.
GP3 is input-only because it is multiplexed with the MCLR reset pin - configuration bits must select MCLR or GP3 function, and once configured as GP3, the MCLR function is disabled. The OTP program memory can be programmed only once; for prototyping, use the PIC12C509A-04I/JW UV-erasable windowed version or switch to the Flash-based PIC12F509. The internal 4 MHz RC oscillator drifts approximately +/- 1 percent over voltage and temperature per the datasheet, so do not use it for UART baud-rate generation without calibration.
The 8-pin DFN-S (6x5 mm) package has a center exposed pad (EP) that must be soldered to the PCB land pattern for mechanical reliability and thermal dissipation. The DFN-S land pattern is NOT pin-to-pin compatible with the 8-pin SOIC land pattern, so a PCB designed for the SOIC-8 variants (e.g., PIC12C509A-04I/SN) will not accept the DFN-S MF variant without board rework. When migrating between the two, design two separate land patterns or use a footprint that supports both packages on different boards.
Compliance Information
RoHS compliant per Microchip product page. Not AEC-Q100 qualified; the part is intended for industrial and consumer applications. PIC12C509A-04I/MF is listed as obsolete on the Microchip website as of 2026-09-14.
