PIC12C509A-04E/SM - 8-bit 4MHz OTP MCU 1.5KB | Microchip
MPN: PIC12C509A-04E/SM ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $2.68 | $2.68 |
| 10 | $2.41 | $24.10 |
| 100 | $2.14 | $214.00 |
| 500 | $1.93 | $965.00 |
| 1,000 | $1.74 | $1,740.00 |
| 3,000 | $1.55 | $4,650.00 |
PIC12C509A-04E/SM Overview
An 8-bit microcontroller (MCU) is a small computer-on-a-chip integrating an 8-bit CPU, program memory (ROM/Flash/OTP), data RAM, I/O peripherals, and timers on a single die. The PIC12C509A belongs to the baseline PIC12C family, which targets cost-sensitive, space-constrained embedded applications. Within the broader taxonomy it sits as: 8-bit MCU -> microcontroller -> embedded processor -> semiconductor device. Its RISC Harvard architecture separates program and data buses for predictable single-cycle instruction execution, while CMOS process technology minimizes quiescent current for battery-powered designs.
Key features include an 8-bit real-time clock/counter (TMR0) with programmable prescaler, internal 4MHz RC oscillator (and external oscillator option), Power-On Reset (POR), Device Reset Timer (DRT), Watchdog Timer (WDT) with its own dedicated on-chip RC oscillator for reliable operation, and programmable code protection. It supports 1,000,000 erase/write cycles on internal EEPROM emulation cells and operates over 2.5V to 5.5V across the extended -40C to +125C industrial temperature range.
The architecture uses a 12-bit instruction word with 8-bit data path and a two-stage pipeline, achieving deterministic interrupt latency. The OTP program memory is factory-or-user-programmable using Microchip's development tools, while internal EEPROM emulation provides 16 bytes of non-volatile data storage. The WDT's independent RC oscillator ensures reliable system recovery even when the main clock fails - critical for unattended industrial and appliance installations.
Typical applications include automotive subsystems (interior lighting, sensor interfaces), industrial control (small appliance controllers, fan drivers, low-end sensor signal conditioning), consumer electronics (remote controls, toys, LED drivers), and IoT edge nodes. The 6 I/O pins support direct LED drive, button input scanning, and serial bit-banged protocols (UART/IR) without external peripherals.
When designing with this device, note that OTP memory cannot be re-programmed - use PIC12F509 (Flash) for prototypes or PIC12C509A for production. The 8-pin SOIJ package is more compact than standard SOIC but requires reflow-compatible land patterns. Ensure the WDT is enabled via configuration bits for unattended applications.
This page synthesizes distributor pricing, drop-in package equivalents, and practical design considerations not found in the standalone manufacturer datasheet, accelerating BOM selection for cost-sensitive 8-bit MCU designs.
Drop-in alternatives for PIC12C509A-04E/SM — 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-04E/SM (same form factor and footprint) — differing in Core Architecture, Package, Program Memory Size, Timers, Data EEPROM.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PIC12C509A-04/SM
✅ Drop-In✓ In Stock
$0.99 / Unit
View Datasheet →PIC12C509A-04I/SM
✅ Drop-In✓ In Stock
$0.93 / Unit
View Datasheet →PIC12C508A-04E/SM
✅ Drop-In📋 Reference alternative (not in catalog)
PIC12C509A-04E/SN
✅ Drop-In📋 Reference alternative (not in catalog)
PIC12C508A-04I/SM
✅ Drop-In✓ In Stock
$1.05 / Unit
View Datasheet →PIC12C509A-04E/SM Maximum Ratings & Electrical Characteristics
| Core Architecture | PIC 8-bit RISC (Harvard) |
| Program Memory Type | OTP (One-Time Programmable) |
| Program Memory Size | 1.5 KB (1K x 12) |
| Data RAM | 41 bytes |
| Data EEPROM | 0 bytes (no on-chip EEPROM) |
| Maximum Clock Frequency | 4 MHz |
| Instruction Execution Time | 1 us (at 4 MHz) |
| Number of Instructions | 33 single-word |
| Operating Voltage Range | 2.5 V to 5.5 V |
| Operating Temperature Range | -40 C to +125 C (Extended) |
| Number of I/O Pins | 6 |
| Timers | 1 x 8-bit (TMR0 with programmable prescaler) |
| Watchdog Timer (WDT) | Yes, with dedicated on-chip RC oscillator |
| Power-On Reset (POR) | Yes |
| Device Reset Timer (DRT) | Yes |
| Code Protection | Programmable |
| ADC | None |
| Package | 8-SOIJ (SM) |
| Mounting Type | Surface Mount |
| RoHS Status | Compliant |
PIC12C509A-04E/SM Pin Configuration
| Pin 1 | GP5/OSC1/CLKIN — Bidirectional I/O pin / oscillator crystal input / external clock input |
| Pin 2 | GP4/OSC2/CLKOUT — Bidirectional I/O pin / oscillator crystal output / clock output |
| Pin 3 | GP3/MCLR/VPP — Bidirectional I/O pin / Master Clear Reset (active low) / programming voltage input |
| Pin 4 | GP2/T0CKI — Bidirectional I/O pin / Timer0 clock input |
| Pin 5 | GP1 — Bidirectional I/O pin |
| Pin 6 | GP0 — Bidirectional I/O pin |
| Pin 7 | VSS — Ground reference |
| Pin 8 | VDD — Positive supply voltage (2.5V to 5.5V) |
Typical Applications
PIC12C509A-04E/SM is suitable for 6 applications: Automotive Interior Lighting Controllers, Small Appliance Control Boards, IR Remote Control Transmitters, Battery-Powered Sensor Interfaces, Consumer Toy and Hobby Electronics, Industrial Sensor Signal Conditioning.
Automotive Interior Lighting Controllers
The PIC12C509A-04E/SM is well-suited for automotive interior lighting modules such as dome lamps, courtesy lights, and ambient LED strips where the extended -40C to +125C temperature range matches cabin and door-panel thermal stress. Its 6 I/O pins directly drive low-current LED strings or relay coils via MOSFETs, while the dedicated WDT with independent RC oscillator recovers the lamp controller from clock faults. The 1.5KB OTP holds fade-table timing and PWM sequences for mood lighting. Compared with Flash MCUs, OTP offers lower unit cost at high volumes - critical for cost-sensitive automotive Tier-1 lighting assemblies.
Recommended
Small Appliance Control Boards
The PIC12C509A-04E/SM serves as the main controller in small appliances like toaster ovens, coffee makers, blenders, and fans where 6 I/O pins suffice for button input, LED indicators, and TRIAC/relay drive via optocouplers. The 1 us instruction execution at 4 MHz handles simple state machines for heating cycles, timer logic, and sensor sampling with deterministic timing. Its 2.5V to 5.5V supply range supports both 3.3V sensor interfaces and 5V relay drivers from a single MCU. OTP memory prevents firmware tampering - important for branded appliances - while the Watchdog Timer recovers the controller from power-line glitches common in motor-driven loads.
Recommended
IR Remote Control Transmitters
In IR remote control transmitters, the PIC12C509A-04E/SM runs the RC5/RC6 or SIRC protocol timing with 33 single-word instructions executed in 1 us at 4 MHz - sufficient for carrier generation, button matrix scanning, and protocol frame encoding. The 6 I/O pins directly drive IR LEDs via a transistor and scan up to a 3x3 button matrix. The 2.5V minimum operating voltage supports 2xAAA battery packs down to 2.0V with reduced oscillator accuracy. OTP prevents code cloning by competitors, protecting proprietary remote protocols in consumer AV equipment and HVAC thermostats.
Recommended
Battery-Powered Sensor Interfaces
The PIC12C509A-04E/SM interfaces with simple analog sensors in 2xAA battery-powered IoT edge nodes where its 2.5V minimum supply extends operating life below typical 3V Lithium coin-cell cutoffs. Sleep current in the microamp range combined with WDT wake-up intervals enables multi-year battery life for door/window contact sensors, leak detectors, and remote temperature loggers. The 1.5KB OTP holds the wake-up scheduler and basic sensor linearization tables. Industrial -40C to +125C support covers outdoor installations and unheated warehouses where consumer-grade MCUs fail.
Recommended
Consumer Toy and Hobby Electronics
Toy manufacturers leverage the PIC12C509A-04E/SM for cost-engineered products like talking dolls, model train controllers, LED light-up novelties, and educational electronics kits where sub-$3 unit pricing is mandatory. The 8-SOIJ package fits into compact toy enclosures, and the 33-instruction RISC core is easy for entry-level embedded engineers to program. The OTP memory discourages code cloning by competitors in the price-sensitive toy market. WDT recovery ensures toys never lock up completely - important for parental satisfaction - and the 6 I/O pins directly drive small speakers via PWM and multiple LEDs without external drivers.
Recommended
Industrial Sensor Signal Conditioning
In industrial sensor transmitter modules, the PIC12C509A-04E/SM performs sensor linearization and 4-20mA loop drive control via PWM for process control instrumentation. The 1 us instruction execution handles PID loops at modest sample rates (10-100 Hz) for temperature, pressure, and flow transmitters. The extended -40C to +125C operating temperature meets outdoor and factory-floor thermal demands. OTP protects proprietary calibration algorithms while the WDT with independent RC oscillator ensures the transmitter recovers from EMI-induced clock faults common near VFD motor drives and switching power supplies.
Recommended
Recommended Products Summary
Engineering reference data for PIC12C509A-04E/SM — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC12C509A-04/SM | PIC12C509A-04I/SM | PIC12C508A-04E/SM | PIC12C509A-04E/SN | PIC12C508A-04I/SM |
|---|---|---|---|---|---|---|
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Package | 8-SOIJ (SM) | 8-SOIJ (SM) - same | 8-SOIJ (SM) - same | 8-SOIJ (SM) - same | 8-SOIC (SN) - different land pattern | 8-SOIJ (SM) - same |
| Program Memory | 1.5 KB (1K x 12) OTP | 1.5 KB OTP | 1.5 KB OTP | 0.75 KB OTP (-50%) | 1.5 KB OTP | 0.75 KB OTP (-50%) |
| Data RAM | 41 bytes | 41 bytes | 41 bytes | 25 bytes (-39%) | 41 bytes | 25 bytes (-39%) |
| Maximum Clock | 4 MHz | 4 MHz | 4 MHz | 4 MHz | 4 MHz | 4 MHz |
| Operating Voltage | 2.5 V to 5.5 V | 2.5 V to 5.5 V | 2.5 V to 5.5 V | 2.5 V to 5.5 V | 2.5 V to 5.5 V | 2.5 V to 5.5 V |
| Operating Temperature | -40 C to +125 C (Extended) | 0 C to +70 C (Commercial) | -40 C to +85 C (Industrial) | -40 C to +125 C (Extended) | -40 C to +125 C (Extended) | -40 C to +85 C (Industrial) |
| Number of I/O Pins | 6 | 6 | 6 | 6 | 6 | 6 |
| Watchdog Timer | Yes (dedicated RC osc) | Yes (dedicated RC osc) | Yes (dedicated RC osc) | Yes (dedicated RC osc) | Yes (dedicated RC osc) | Yes (dedicated RC osc) |
| ADC | None | None | None | None | None | None |
Key Differentiators
- Extended -40C to +125C operating temperature range (vs PIC12C509A-04/SM (commercial 0C to +70C))
- Largest OTP program memory in PIC12C5xx 8-pin family (vs PIC12C508A-04E/SM (0.75 KB))
- 8-SOIJ package for compact SMD designs (vs PIC12C509A-04/P (PDIP-8 through-hole))
Design Notes
The PIC12C509A uses One-Time-Programmable (OTP) memory that cannot be electrically erased - mistakes in firmware require physical device replacement. For development cycles, substitute the PIC12F509 (Flash-based) which has identical pinout and peripherals but supports in-circuit re-programming via ICSP. Also note that GP3 is input-only on most PIC12 baseline parts - verify direction register behavior in DS40139E before assigning GP3 as an output. The MCLR function shares GP3 by default; to use GP3 as a digital input, configure MCLR as an internal reset only via the configuration word.
The PIC12C509A-04E/SM operates from 2.5V to 5.5V and lacks an internal brown-out reset (BOR) on older revisions - external voltage supervision (e.g., MCP100 or TPS38xx) is recommended for battery-powered designs to prevent code corruption during voltage droops. Decouple VDD with a 100 nF ceramic capacitor placed within 5 mm of the VDD pin, plus a 10 uF bulk capacitor if the supply has high inductance. The internal 4 MHz RC oscillator accuracy is typically +/-2% at 5V/25C but degrades at temperature extremes - calibrate OSCCAL register for timing-critical UART or IR protocols.
The 8-SOIJ (SM) package has a 5.00 mm body width with 1.27 mm pitch J-lead terminations - design the land pattern per Microchip package drawing for reliable reflow soldering. Unlike standard SOIC-8 (3.90 mm body), the SOIJ package is wider and requires a different PCB footprint; do not use SOIC-8 land patterns with SOIJ parts. For hand prototyping or breadboarding, use the PIC12C509A-04/P (PDIP-8) variant instead. The exposed die paddle on SOIJ improves thermal performance but requires via stitching to inner ground plane for best results.
Compliance Information
RoHS and lead-free compliant per Microchip product page. Not AEC-Q100 qualified - not suitable for safety-critical automotive applications. Conflict-mineral declaration available from Microchip.
