PIC12C509A-04I/P - 8-bit 4MHz OTP MCU, 1.5KB | Microchip
MPN: PIC12C509A-04I/P ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $1.62 | $1.62 |
| 10 | $1.42 | $14.20 |
| 100 | $1.18 | $118.00 |
| 500 | $1.02 | $510.00 |
| 1,000 | $0.89 | $890.00 |
PIC12C509A-04I/P Overview
A microcontroller (MCU) is a single-chip computer that integrates a CPU core, program memory, working RAM, and programmable I/O on one die. Within the broader product taxonomy, an 8-bit RISC MCU is a sub-category of microcontrollers -> microcontrollers (Integrated Circuits) -> semiconductors. The PIC12C5XX family, including PIC12C508, PIC12C509, PIC12C509A, PIC12CR509A, and PIC12CE519, is the compact 8-pin cousin of the classic PIC16C5X architecture and is well known for fitting control logic into a DIP-8 footprint.
Key features of the PIC12C509A-04I/P include 4 MHz maximum oscillator frequency (the "/04" suffix), an industrial-grade operating temperature range of -40C to +85C (the "I" suffix), 6 bidirectional I/O pins multiplexed with the device's peripherals, an 8-bit timer/counter (TMR0) with an 8-bit programmable prescaler, a watchdog timer with its own on-chip RC oscillator for reliable resets, and a power-on reset circuit. It is built on CMOS EPROM/OTP technology and operates from 2.5V to 5.5V VDD, drawing only microampere-level sleep current.
From an architectural perspective, the PIC12C509A uses a Harvard RISC architecture with separate program and data paths, a 12-bit-wide program word, and a two-level hardware stack. The PIC12C509A revision adds improvements in oscillator tolerance, DC RAM, and reset behavior versus the original PIC12C509, which is why datasheet users normally select the 'A' silicon for new designs. Program memory is OTP, so firmware is committed during device programming and is not field-rewriteable - choose PIC12CR509A or PIC12F509 if in-system reprogrammability is required.
Typical applications for the PIC12C509A-04I/P include appliance and white-goods controllers, automotive body and interior electronics (non-safety), small sensor signal processing and conditioning, smart battery chargers and low-cost power management controllers, and consumer remote controls. The industrial temperature grade makes it appropriate for outdoor controllers, building automation, and harsh industrial environments.
When designing with this device, observe the 4 MHz maximum clock, ensure that the MCLR pin is properly tied through the recommended RC reset network or pulled high, and respect the 25 mA per-pin / 150 mA per-port sink limits. Because the program memory is OTP, a device programmer (e.g., PICkit or MPLAB ICD) must be used during prototype bring-up before committing to masked/OTP silicon.
This page synthesizes drop-in same-package alternatives, distributor pricing as of 2026-10-09, and practical design considerations that go beyond what is in the manufacturer datasheet.
Drop-in alternatives for PIC12C509A-04I/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 PIC12C509A-04I/P (same form factor and footprint) — differing in Program Memory Size, Core Architecture, I/O Pins, Package, Program Memory Type.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PIC12C509A-04/P
✅ Drop-In📋 Reference alternative (not in catalog)
PIC12C509A-04I/SM
✅ Drop-In✓ In Stock
$0.93 / Unit
View Datasheet →PIC12C508A-04I/P
✅ Drop-In✓ In Stock
$0.81 / Unit
View Datasheet →PIC12C509-04I/P
✅ Drop-In📋 Reference alternative (not in catalog)
PIC12CE519-04I/P
✅ Drop-In📋 Reference alternative (not in catalog)
PIC12F509-I/P
✅ Drop-In✓ In Stock
$0.86 / Unit
View Datasheet →PIC12C509A-04I/P Maximum Ratings & Electrical Characteristics
| Core Architecture | PIC 8-bit RISC (Enhanced PIC16C5X) |
| Program Memory Type | OTP (One-Time-Programmable EPROM) |
| Program Memory Size | 1.5 KB (1K x 12) |
| RAM | 41 bytes |
| Data EEPROM | Not present |
| Maximum CPU Frequency | 4 MHz |
| Instruction Set Size | 33 single-word instructions |
| Instruction Cycle Time | 1 microsecond at 4 MHz |
| I/O Pins | 6 bidirectional |
| Timers | 1 x 8-bit (TMR0 with programmable prescaler) |
| Watchdog Timer | Yes (with on-chip dedicated RC oscillator) |
| Operating Voltage Range | 2.5 V to 5.5 V |
| Operating Temperature Range | -40 C to +85 C (Industrial) |
| Reset Circuit | Power-on Reset (POR) + MCLR pin |
| Package | 8-pin PDIP (through-hole) |
| Mounting Type | Through-Hole |
| MSL Level | 1 (not moisture-sensitive) |
PIC12C509A-04I/P Pin Configuration
| Pin 1 | GP5/OSC1/CLKIN — General-purpose I/O / oscillator input / external clock input |
| Pin 2 | GP4/OSC2/CLKOUT — General-purpose I/O / oscillator output / clock output |
| Pin 3 | GP3/MCLR/VPP — General-purpose input / master clear reset (active-low) / programming voltage |
| Pin 4 | GP2/T0CKI — General-purpose I/O / TMR0 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 supply voltage (2.5 V to 5.5 V) |
Typical Applications
PIC12C509A-04I/P is suitable for 7 applications: Appliance and White-Goods Controllers, Automotive Body and Interior Electronics, Sensor Signal Conditioning and Processing, Smart Battery Chargers and Power Management, Consumer Remote Controls and IR Interfaces, Industrial Control Logic Replacement, Educational and Hobby Prototyping.
Appliance and White-Goods Controllers
The PIC12C509A-04I/P is well suited to appliance controllers (timer relays, mode selectors, sensor interfaces in washing machines, microwaves, and dishwashers) thanks to its 4 MHz RISC performance, 1.5 KB OTP for compact firmware, and 6 bidirectional I/O pins. Its 1 microsecond instruction execution enables reliable mains-frequency timing via TMR0, while the integrated watchdog timer with a dedicated RC oscillator catches software lockups without external components. Industrial-grade -40 C to +85 C operation covers kitchen and laundry environments, and the 8-pin PDIP footprint keeps the BOM and PCB area small for cost-driven appliance designs.
Recommended
Automotive Body and Interior Electronics
The PIC12C509A-04I/P serves automotive body and interior applications such as lighting controllers, mirror adjusters, seat-position memory, and simple HVAC mode logic where AEC-Q100 is not mandated. Its 8-pin PDIP footprint, 4 MHz RISC core, and 1.5 KB program memory fit into very small modules, while the watchdog timer and POR circuit ensure recovery from transient electrical noise common in 12 V automotive supplies. Although it is industrial-grade (-40 C to +85 C) rather than AEC-Q100, the family is recommended by Microchip for non-safety automotive subsystems where cost and footprint dominate the design trade-off.
Recommended
Sensor Signal Conditioning and Processing
The PIC12C509A-04I/P is a strong fit for low-cost sensor signal-conditioning front ends (thermistor conditioning, photo-detector pulse counting, humidity sensors, and contact debouncing) thanks to its 6 I/O pins, TMR0 for timing/pulse counting, and 1.5 KB OTP for state-machine logic. Its 4 MHz core is fast enough to digitize low-rate analog signals via RC-charge timing or software PWM, while the integrated watchdog prevents firmware lockups from EMI-induced runaway. The 8-pin PDIP package allows technicians to swap sensors quickly in field installations.
Recommended
Smart Battery Chargers and Power Management
For low-cost smart battery chargers and simple power-management supervisors, the PIC12C509A-04I/P delivers 4 MHz RISC performance and 6 I/O pins in an 8-pin PDIP at a unit cost that fits consumer products. Its TMR0 module and software PWM can regulate charge current via MOSFET gate drive on a single I/O pin, while the watchdog and brown-out blocks protect batteries from firmware runaway. Operating from 2.5 V to 5.5 V allows direct connection to single-cell Li-Ion or multi-cell NiMH packs without a pre-regulator.
Recommended
Consumer Remote Controls and IR Interfaces
The PIC12C509A-04I/P is widely used in consumer remote controls and IR transceivers where a 6-I/O pin MCU with 1.5 KB OTP can encode RC-32 or RC-5 protocols using TMR0 interrupts. Its 1 microsecond instruction cycle lets the 4 MHz core generate accurate 38 kHz or 40 kHz IR carrier modulation with minimal software overhead, and the 8-pin PDIP footprint minimizes BOM cost for ultra-cheap consumer SKUs. Industrial temperature range covers residential thermal and storage conditions for retail-channel products.
Recommended
Industrial Control Logic Replacement
The PIC12C509A-04I/P replaces discrete 74HC logic gates and small relay-logic controllers in industrial control systems by collapsing boolean logic, timing, and I/O conditioning into a single 8-pin PDIP. It runs at 4 MHz with 33 RISC instructions and 1.5 KB of OTP, which is enough for sequence controllers, conveyor timers, and pump multiplexers in non-safety installations. The -40 C to +85 C industrial temperature range covers outdoor enclosures and most factory environments, while the integrated watchdog timer with a dedicated on-chip RC oscillator ensures recovery from supply transients and EMI-induced hangs.
Recommended
Educational and Hobby Prototyping
The PIC12C509A-04I/P is a favorite for educational and hobby projects because of its 8-pin PDIP breadboard-friendly package, only 33 single-word instructions, and 4 MHz cores that can be programmed with low-cost PICkit programmers. Its 1.5 KB OTP forces good design discipline, while the integrated watchdog and POR simplify robust code teaching examples. The PIC12C5XX family is a documented entry point in Microchip's training materials and remains widely stocked through DigiKey and Mouser for student and maker use cases.
Recommended
Recommended Products Summary
Engineering reference data for PIC12C509A-04I/P — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC12C509A-04/P | PIC12C508A-04I/P | PIC12C509-04I/P | PIC12CE519-04I/P | PIC12F509-I/P |
|---|---|---|---|---|---|---|
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Package | PDIP-8 (through-hole) | PDIP-8 - same | PDIP-8 - same | PDIP-8 - same | PDIP-8 - same | PDIP-8 - same |
| Core Architecture | 8-bit PIC RISC (12-bit instruction) | 8-bit PIC RISC (12-bit instruction) | 8-bit PIC RISC (12-bit instruction) | 8-bit PIC RISC (12-bit instruction, pre-A) | 8-bit PIC RISC (12-bit instruction) | 8-bit PIC RISC (14-bit instruction) |
| Program Memory | 1.5 KB OTP (1K x 12) | 1.5 KB OTP | 1.0 KB OTP (-33%) | 1.5 KB OTP (pre-A silicon) | 1.5 KB OTP | 1.5 KB Flash |
| RAM | 41 bytes | 41 bytes | 41 bytes | 41 bytes (less DC RAM) | 41 bytes | 41 bytes |
| Maximum Frequency | 4 MHz | 4 MHz | 4 MHz | 4 MHz | 4 MHz | 8 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 | 2.0 V to 5.5 V (wider) |
| Operating Temperature | -40 C to +85 C (Industrial) | 0 C to +70 C (Commercial) | -40 C to +85 C (Industrial) | -40 C to +85 C (Industrial) | -40 C to +85 C (Industrial) | -40 C to +85 C (Industrial) |
| Memory Type | OTP EPROM | OTP EPROM | OTP EPROM | OTP EPROM | OTP EPROM + on-chip EEPROM (16 bytes) | Flash (re-programmable) |
Key Differentiators
- Industrial temperature grade in 8-pin PDIP (vs PIC12C509A-04/P)
- Larger program memory than PIC12C508A family (vs PIC12C508A-04I/P)
- Improved 'A' silicon revision over pre-A PIC12C509 (vs PIC12C509-04I/P)
- OTP simplicity versus Flash reprogrammability (vs PIC12F509-I/P)
Design Notes
The PIC12C509A-04I/P operates from a single 2.5 V to 5.5 V VDD supply and has no internal voltage regulator. Place a 0.1 microfarat ceramic bypass capacitor as close as possible to pin 8 (VDD) and pin 7 (VSS) to suppress switching transients from the internal clock edges. For battery-powered designs, the PIC12C509A sleep current is in the microampere range, but watch-dog-timer-enabled sleep must be balanced against required wake-up latency.
Keep the oscillator traces (GP5/OSC1/CLKIN and GP4/OSC2/CLKOUT) as short as possible and surround them with a ground pour to minimize stray capacitance that can shift the internal oscillator frequency. The MCLR pin (GP3/MCLR/VPP, pin 3) requires a 10-50 kohm pull-up to VDD if no external reset is needed; add a 0.1 microfarat capacitor and series resistor only if a controlled power-on-reset edge is required by your application. All other I/O should be left open or tied to known logic states to avoid floating inputs.
Do not attempt to program the PIC12C509A-04I/P in-circuit unless your board meets Microchip's in-circuit-serial-programming (ICSP) layout guidelines - the MCLR/VPP pin and GP1 must be reachable by the programmer. Because the program memory is OTP, a programming error means the device is unusable; always verify on a windowed PIC12C509A prototype before committing to OTP volume programming. The 4 MHz speed suffix is the maximum oscillator frequency; do not run the device with an external clock above 4 MHz.
The PIC12C509A-04I/P in PDIP-8 has a low quiescent operating current (low milliampere range at 4 MHz) so internal power dissipation is dominated by I/O pin drive, not the core. The DIP-8 package has excellent thermal conduction through its leads; in practice the device does not require a heatsink. For high-temperature industrial installations above the rated +85 C maximum, derate or migrate to a wider-temperature PIC16F part.
Compliance Information
RoHS and REACH status not explicitly stated in the verified web data snippets; the part is generally considered lead-free (Pb-free) per Microchip manufacturing standards. Not AEC-Q100 qualified - the device targets industrial and consumer markets. RoHS marked as [DATA_NEEDED] in specs because the verified web data did not include a direct RoHS statement; consult Microchip's product compliance documentation for authoritative certification status.
