PIC12C509A-04I/SM - 8-bit 4MHz OTP MCU 1.5KB | Microchip
MPN: PIC12C509A-04I/SM ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $1.46 | $1.46 |
| 10 | $1.31 | $13.10 |
| 100 | $1.17 | $117.00 |
| 500 | $1.04 | $520.00 |
| 1,000 | $0.93 | $930.00 |
PIC12C509A-04I/SM Overview
What is an 8-bit OTP microcontroller? An 8-bit OTP microcontroller is a small, low-pin-count programmable logic controller that stores its program code in one-time-programmable EPROM rather than Flash or EEPROM. OTP parts occupy the lowest-cost tier of the microcontroller market and are widely used in cost-sensitive, high-volume products where firmware will not change after programming. They sit within the broader category hierarchy: microcontroller (MCU) -> 8-bit MCU -> baseline PIC12 family -> PIC12C5xx series -> PIC12C509A sub-family.
Key features of the PIC12C509A-04I/SM include a wide operating voltage range from 2.5 V to 5.5 V (industrial, -40C to +85C), an integrated 4 MHz internal RC oscillator option plus external oscillator support, Power-On Reset (POR), Watchdog Timer (WDT) with on-chip RC oscillator, 5 GPIO pins (6 I/O on some variants), and code protection via EPROM bit. The device draws very low operating current and supports sleep mode for battery-powered designs.
Architecturally, the PIC12C509A uses a 12-bit program word width and Harvard-style separate program/data buses, enabling single-cycle instruction fetch with deterministic 1 us execution at 4 MHz. The device includes a hardware ALU, 8-level deep stack, and self-programming capability. Compared to the PIC12C508A (which has 0.75 KB / 512 x 12 program memory), the PIC12C509A doubles the program memory and is otherwise pin-compatible.
Typical applications include consumer appliance controllers, sensor signal conditioning, LED driving logic, automotive body electronics sub-modules, simple remote-control encoders, battery chargers, and industrial timer/counter modules. The 8-pin SOIJ package supports compact surface-mount assembly in space-constrained PCB layouts.
Design considerations include the OTP nature - code must be perfect before programming as it cannot be erased or rewritten. Engineers should prototype with the PIC12F509 (Flash equivalent) before committing to OTP for production. The /SM suffix denotes the SOIJ package with industrial (-40C to +85C) temperature grade.
This page synthesizes XAIPART distributor pricing, drop-in same-brand and cross-brand alternatives, application reference designs, and practical engineering notes beyond the manufacturer datasheet summary.
Drop-in alternatives for PIC12C509A-04I/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-04I/SM (same form factor and footprint) — differing in Core Architecture, I/O Pins, Timers, Data EEPROM, Package.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PIC12C509A-04/SM
✅ Drop-In✓ In Stock
$0.99 / Unit
View Datasheet →PIC12F509-I/SM
✅ Drop-In📋 Reference alternative (not in catalog)
PIC12LC509A-04I/SM
✅ Drop-In📋 Reference alternative (not in catalog)
PIC12C509A-04E/SM
✅ Drop-In✓ In Stock
$1.55 / Unit
View Datasheet →PIC12C509A-04I/MF
✅ Drop-In✓ In Stock
$0.99 / Unit
View Datasheet →PIC12C508A-04I/SM
✅ Drop-In✓ In Stock
$1.05 / Unit
View Datasheet →PIC12C509A-04I/SM Maximum Ratings & Electrical Characteristics
| Product Family | PIC12C5xx Series |
| Core Architecture | 8-bit PIC RISC (Enhanced PIC16C5X) |
| Program Memory Type | OTP EPROM |
| Program Memory Size | 1.5 KB (1K x 12 words) |
| RAM Size | 41 bytes |
| Data EEPROM | None (0 bytes) |
| Maximum Clock Frequency | 4 MHz |
| Instruction Execution Time | 1 us at 4 MHz (200 ns per instruction) |
| Instruction Set Size | 33 single-word instructions |
| Operating Voltage Range | 2.5 V to 5.5 V |
| I/O Pins | 5 (GPIO0-GPIO4, shared with oscillator) |
| Operating Temperature Range | -40C to +85C (Industrial) |
| Package Type | 8-pin SOIJ (SM) |
| Mounting Type | Surface Mount |
| Integrated Peripherals | POR, WDT, 4 MHz internal RC oscillator option |
| Power-Saving Modes | Sleep mode with WDT wake-up |
| RoHS Status | Compliant |
| MSL Level | 1 (Unlimited at floor life) |
PIC12C509A-04I/SM Pin Configuration
| Pin 1 | GP5/OSC1/CLKIN — General-purpose I/O / oscillator input / external clock input |
| Pin 2 | GP4/OSC2 — General-purpose I/O / oscillator output |
| Pin 3 | GP3/MCLR/VPP — Input-only GPIO / Master Clear reset (active low) / programming voltage input |
| Pin 4 | GP2/T0CKI — General-purpose I/O / Timer0 external clock input |
| Pin 5 | GP1 — General-purpose I/O |
| Pin 6 | GP0 — General-purpose I/O |
| Pin 7 | VSS — Ground reference |
| Pin 8 | VDD — Positive power supply (2.5 V to 5.5 V) |
Typical Applications
PIC12C509A-04I/SM is suitable for 6 applications: Consumer Appliance Controllers, Battery-Powered Sensor Modules, LED Lighting Controllers, Industrial Timer and Counter Modules, Remote Control Encoders, Automotive Accessory Sub-Controllers.
Consumer Appliance Controllers
The PIC12C509A-04I/SM fits consumer appliance controllers (rice cookers, washing machines, microwave ovens) where cost dominates and firmware is locked. Its 1.5 KB OTP memory accommodates simple state-machine code for relay drivers, timer sequencing, and sensor input polling. The 8-pin SOIJ package fits small PCB footprints inside sealed enclosures. Operating voltage from 2.5 V to 5.5 V supports direct connection to rectified mains-derived rails without additional regulators. Designers benefit from the 33-instruction PIC RISC set, which compiles to highly compact code - critical when total program memory is only 1.5 KB. Industrial temperature rating (-40C to +85C) handles under-cabinet kitchen heat. Use MPASM or XC8 compiler; prototypes on PIC12F509 before committing to OTP.
Recommended
Battery-Powered Sensor Modules
The PIC12C509A-04I/SM suits battery-powered sensor modules such as wireless temperature loggers, smoke detector sub-controllers, and remote control encoders. Its 2.5 V to 5.5 V supply range works directly from two AA alkaline cells or a single Li-ion cell with regulation. Sleep current and WDT-driven wake-up enable multi-year battery life when the MCU sleeps between infrequent sensor reads. The 4 MHz internal RC oscillator eliminates the external crystal, reducing BOM cost and board area in space-constrained modules. OTP memory is appropriate because production firmware for sensor modules rarely changes. Industrial temperature rating accommodates outdoor installations. Use the Watchdog Timer and sleep mode to minimize average current draw below 1 uA in standby.
Recommended
LED Lighting Controllers
The PIC12C509A-04I/SM is well-suited for LED lighting controllers in decorative strips, signage, and architectural fixtures. With 5 GPIO pins, the MCU can drive multiple LED channels via PWM-emulated bit-banging or interface with external driver ICs like the TLC5940. The 4 MHz clock provides sufficient resolution for 8-bit PWM dimming across hundreds of Hz refresh rates. OTP memory keeps unit cost low for high-volume consumer lighting products. The wide operating voltage (2.5 V to 5.5 V) supports both 3.3 V regulated and 5 V direct LED-driver supplies. The 8-pin SOIJ package minimizes PCB real estate. Program firmware to deliver smooth dimming curves, color-mixing sequences, and DMX-512 decode for professional fixtures.
Recommended
Industrial Timer and Counter Modules
The PIC12C509A-04I/SM serves industrial timer and counter modules including conveyor controllers, machine cycle timers, and pump duty-cycle managers. The integrated 16-bit Timer0 with external T0CKI input on pin 4 captures external pulse counts up to 4 MHz. Industrial -40C to +85C temperature rating supports factory floor deployment. The PIC RISC architecture executes deterministic 1 us instructions, critical for accurate timing loops. OTP memory prevents field firmware tampering in industrial settings. The MCU's small footprint fits inside DIN-rail enclosures. Use the Watchdog Timer to recover from electrical noise-induced lockups common in motor-drive environments.
Recommended
Remote Control Encoders
The PIC12C509A-04I/SM is ideal for remote control encoders in garage door openers, fan controllers, and RF key fobs. Its 1.5 KB program memory holds fixed transmission protocols (PT2262-compatible, EV1527, or custom rolling codes). The 4 MHz internal oscillator drives accurate 38 kHz carrier generation for IR remotes or 315/433 MHz OOK modulation for RF fobs. Sleep current below 1 uA extends coin-cell battery life to multiple years. OTP memory prevents cloning of proprietary transmission codes. Five GPIO pins handle multiple button inputs and status LEDs. Use the WDT to wake the MCU on button press and return to sleep, minimizing standby power.
Recommended
Automotive Accessory Sub-Controllers
The PIC12C509A-04I/SM can be used in non-critical automotive accessory sub-controllers such as interior LED mood lighting, seat heater buttons, and auxiliary accessory timing modules. Note: industrial temperature grade (-40C to +85C) limits deployment to cabin applications; for under-hood or AEC-Q100-mandated designs, use PIC16F or PIC18 automotive-grade parts. The 8-pin SOIJ package fits inside small switch housings and connector modules. The 4 MHz clock generates accurate PWM dimming for cabin lighting. OTP memory locks production firmware to prevent unauthorized modification. Designers should prototype on PIC12F509-I/SM before committing to the OTP variant for production cost savings.
Recommended
Recommended Products Summary
Engineering reference data for PIC12C509A-04I/SM — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC12C509A-04/SM | PIC12F509-I/SM | PIC12LC509A-04I/SM | PIC12C509A-04E/SM | PIC12C508A-04I/SM |
|---|---|---|---|---|---|---|
| Package | 8-pin SOIJ (SM) | 8-pin SOIJ (SM) - same | 8-pin SOIJ (SM) - same | 8-pin SOIJ (SM) - same | 8-pin SOIJ (SM) - same | 8-pin SOIJ (SM) - same |
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Program Memory | 1.5 KB OTP | 1.5 KB OTP | 1.5 KB Flash | 1.5 KB OTP | 1.5 KB OTP | 0.75 KB OTP |
| Operating Voltage | 2.5 V to 5.5 V | 2.5 V to 5.5 V | 2.0 V to 5.5 V | 2.0 V to 5.5 V | 2.5 V to 5.5 V | 2.5 V to 5.5 V |
| Operating Temperature | -40C to +85C | 0C to +70C | -40C to +85C | -40C to +85C | -40C to +125C | -40C to +85C |
| Memory Type | OTP EPROM | OTP EPROM | Flash (re-programmable) | OTP EPROM | OTP EPROM | OTP EPROM |
| Max Clock Frequency | 4 MHz | 4 MHz | 4 MHz (8 MHz internal) | 4 MHz | 4 MHz | 4 MHz |
| I/O Pins | 5 GPIO | 5 GPIO | 5 GPIO | 5 GPIO | 5 GPIO | 5 GPIO |
| Approx Unit Price (Qty 1) | USD 1.46 | USD 1.20 (est.) | USD 1.70 (est.) | USD 1.55 (est.) | USD 1.80 (est.) | USD 1.30 (est.) |
Key Differentiators
- Industrial -40C to +85C temperature grade in same package (vs PIC12C509A-04/SM)
- Flash reprogrammability with identical pinout and memory (vs PIC12F509-I/SM)
- Extended -40C to +125C temperature for harsh environments (vs PIC12C509A-04E/SM)
Design Notes
Critical: the PIC12C509A uses OTP EPROM, not Flash. Code cannot be erased or rewritten after programming. Always prototype and validate firmware on the Flash-based PIC12F509 (same 8-pin SOIJ pinout) before committing to OTP for production. A single firmware bug in production OTP parts requires complete scrap and re-spin of new silicon. The '04' suffix in the part number denotes 4 MHz maximum clock; do not exceed this frequency or instruction timing becomes invalid.
Recommended: place a 100 nF decoupling capacitor as close as possible to the VDD pin (pin 8). Add a 10 uF bulk capacitor if the supply line is shared with other switching loads. For MCLR (pin 3), either tie directly to VDD or use the internal MCLR configuration via the configuration word. If using external MCLR reset, add a 10 kohm pull-up to VDD. For battery-powered designs, place the MCU on the same ground plane as the sensor to minimize noise coupling.
Recommended: enable Sleep mode and use the Watchdog Timer (WDT) for periodic wake-up to minimize average current draw in battery-powered applications. Typical sleep current is sub-1 uA. The internal 4 MHz RC oscillator eliminates the external crystal, saving cost and board area. For very low-power designs, clock the MCU at the lowest frequency that meets timing requirements - 32 kHz operation from an external watch crystal is possible by switching oscillator modes. Disable unused peripherals via the configuration word to minimize quiescent current.
Optional: the PIC12C509A in the 8-pin SOIJ package dissipates negligible power due to its CMOS construction. Junction temperature is typically within 5C of ambient. No heatsink or thermal management is required. Verify in high-temperature environments (-40C to +85C industrial grade) that the WDT and internal oscillator drift stay within timing budget; the internal RC oscillator drifts approximately +/- 2% over the full temperature range. For designs requiring tight timing accuracy, use an external crystal instead of the internal oscillator.
Compliance Information
RoHS compliant per Microchip product page. Industrial temperature grade (-40C to +85C); not AEC-Q100 qualified for automotive under-hood applications. Lead-free terminations. Halogen-free status not explicitly stated in available datasheets.
