PIC12C509A-04E/P - 8-Bit 4MHz OTP MCU 1.5KB | Microchip
MPN: PIC12C509A-04E/P ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $1.6 | $1.60 |
| 10 | $1.51 | $15.10 |
| 100 | $1.36 | $136.00 |
| 500 | $1.21 | $605.00 |
| 1,000 | $1.1 | $1,100.00 |
PIC12C509A-04E/P Overview
A microcontroller (MCU) is a single-chip computer that integrates a CPU, RAM, non-volatile program memory, and peripheral interfaces onto one IC. The 8-bit PIC MCU family from Microchip uses a RISC (Reduced Instruction Set Computer) architecture with only 33 single-word single-cycle instructions, so most instructions execute in 1 us at 4 MHz. Within the broader taxonomy, the PIC12C509A belongs to the 8-bit PIC microcontrollers category, which sits under the wider umbrella of microcontrollers, embedded processors, and ultimately semiconductor integrated circuits.
Key features of this device include six general-purpose digital I/O pins with 25 mA source/sink drive capability, selectable oscillator modes (internal 4 MHz RC, external RC, external crystal, or low-cost RC), Power-On Reset (POR), Device Reset Timer (DRT), in-circuit serial programming (ICSP) support, and programmable code protection. The OTP program memory is one-time programmable yet retains field-reprogrammability through the ICSP interface during development, simplifying firmware iteration.
The PIC12C509A's RISC core executes instructions in a single cycle (1 us at 4 MHz) except for program branches (two cycles), and its Harvard architecture with separate program and data buses lets the CPU fetch the next instruction while executing the current one. The integrated 4 MHz internal RC oscillator with programmable calibration removes the need for external crystals in cost-sensitive designs, while external oscillator options support timing-critical or low-EMI applications.
Typical applications include automotive body and chassis subsystems, industrial sensor interfaces and small appliance controllers, low-end consumer electronics, and remote control transmitters. The wide 3.0V to 5.5V operating range and extended temperature grade make it well-suited to harsh-environment 8-bit embedded designs where cost and pin count dominate over raw computational horsepower.
When designing with the PIC12C509A-04E/P, the main trade-off is OTP memory: once locked, the program cannot be changed. Designers should plan for ICSP header access and consider whether an EPROM- or Flash-based cousin (PIC12F509, PIC10F202) is more appropriate for firmware that will be revised in the field. The 6 I/O pins also limit peripheral count, often requiring I/O expansion via shift registers or I2C port expanders.
This page synthesizes distributor pricing, drop-in alternatives within the PIC12C family, and practical design notes not found in the manufacturer datasheet alone, providing a single reference for BOM selection, lifecycle planning, and cross-vendor risk mitigation.
Drop-in alternatives for PIC12C509A-04E/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-04E/P (same form factor and footprint) — differing in Package, Watchdog Timer, Program Memory Size, Operating Temperature, Timers.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PIC12F509-I/P
✅ Drop-In✓ In Stock
$0.86 / Unit
View Datasheet →PIC12C509A-04/SN
✅ Drop-In✓ In Stock
$0.98 / Unit
View Datasheet →PIC12C509A-04/SM
✅ Drop-In✓ In Stock
$0.99 / Unit
View Datasheet →PIC12C508A-04E/P
✅ Drop-In✓ In Stock
$1.74 / Unit
View Datasheet →PIC12C509-04/P
✅ Drop-In✓ In Stock
$1.18 / Unit
View Datasheet →PIC12C509A-04I/P
✅ Drop-In📋 Reference alternative (not in catalog)
PIC12C509A-04E/P Maximum Ratings & Electrical Characteristics
| Core Architecture | 8-bit PIC RISC |
| Instruction Set | 33 single-word instructions |
| Program Memory Type | OTP (One-Time Programmable) EPROM |
| Program Memory Size | 1.5 KB (1K x 12) |
| RAM | 41 bytes |
| Data EEPROM | None |
| CPU Speed | 4 MHz (1 us instruction cycle) |
| I/O Pins | 6 |
| I/O Sink/Source Current | 25 mA per pin |
| Timers | 1 x 8-bit TMR0 with 8-bit prescaler |
| Watchdog Timer | Yes, with dedicated on-chip RC oscillator |
| Operating Voltage | 3.0 V to 5.5 V |
| Operating Temperature | -40 C to +125 C (Extended "E" grade) |
| Package | 8-pin PDIP (P) |
| Mounting Type | Through-Hole |
| Oscillator Modes | Internal 4 MHz RC, External RC, XT, LP |
| ICSP (In-Circuit Serial Programming) | Yes |
| Code Protection | Programmable |
| RoHS Status | Compliant (lead-free, per Microchip product page) |
PIC12C509A-04E/P Pin Configuration
| Pin 1 | VDD — Positive supply voltage (3.0 V to 5.5 V) |
| Pin 2 | OSC1/CLKIN — Oscillator crystal input or external clock input |
| Pin 3 | OSC2/CLKOUT — Oscillator crystal output or 1/4 clock output |
| Pin 4 | GP3/MCLR — General-purpose I/O (input only) / Master Clear reset |
| Pin 5 | GP2/T0CKI — General-purpose I/O / Timer0 clock input |
| Pin 6 | GP1 — General-purpose bidirectional I/O |
| Pin 7 | GP0 — General-purpose bidirectional I/O |
| Pin 8 | VSS — Ground reference |
Typical Applications
PIC12C509A-04E/P is suitable for 6 applications: Automotive Body Electronics, Industrial Sensor Interface, Remote Control Transmitter, Small Appliance Controller, LED Lighting Controller, Battery-Powered IoT Sensor Node.
Automotive Body Electronics
The PIC12C509A-04E/P fits automotive body-electronics modules such as interior lighting controllers, seat position sensors, and simple HVAC damper drivers where 6 I/O pins and 1.5 KB of OTP code are sufficient. Its 4 MHz RISC core executes 33 single-cycle instructions in 1 us, easily handling brushed-motor PWM, debounced switch scanning, and LIN-bus slave protocol stacks. The extended -40C to +125C temperature grade covers cabin and under-hood thermal envelopes, while 25 mA per-pin drive directly sinks automotive relay coils and LED indicators without external transistors.
Recommended
Industrial Sensor Interface
The PIC12C509A-04E/P serves as a low-cost front-end for industrial 4-20 mA and 0-10 V sensor transmitters, digitizing analog inputs via its analog comparator and PWMing the result onto a current loop. The 4 MHz core and 1 us instruction cycle provide 1 MIPS of processing, sufficient for linearization, cold-junction compensation, and HART-style modulation. The 3.0 V to 5.5 V supply range interfaces directly to 5 V industrial rails, and the integrated 4 MHz RC oscillator eliminates crystal cost in distributed sensor nodes.
Recommended
Remote Control Transmitter
The PIC12C509A-04E/P powers infrared and sub-GHz remote-control transmitters for consumer TV, set-top box, and garage-door applications, where its 6 I/O pins map directly to a button matrix of up to 12 keys (4x3) plus an IR LED driver. The 1.5 KB OTP holds complete RC5/RC6/SIRC encoding tables, and the 25 mA I/O source drive pulses the IR LED at 50 percent duty without an external transistor. The 4 MHz internal RC oscillator and 1.5-3 V operating range extend battery life in coin-cell-powered remotes.
Recommended
Small Appliance Controller
The PIC12C509A-04E/P is well-suited to small kitchen and household appliances such as coffee makers, toasters, and fan speed controllers, where 6 I/O pins drive triac-fired heating elements, sense thermistor inputs, and read push-button user interfaces. The 4 MHz core handles zero-crossing detection, PID-style temperature regulation, and triac phase-angle control in real time. The extended -40C to +125C temperature grade survives the thermal rise inside toaster and coffee-machine enclosures, while 1.5 KB OTP holds complete menu and timing logic.
Recommended
LED Lighting Controller
The PIC12C509A-04E/P drives low-channel-count LED lighting products such as decorative strips, signage, and architectural fixtures by generating hardware PWM on its 6 I/O pins. Each pin delivers 25 mA, enough to sink a chain of 3-5 indicator LEDs through a single resistor. The 4 MHz core supports up to 6 channels of 8-bit PWM at 244 Hz update rate or 4 channels of 10-bit PWM via the TMR0 prescaler. The wide 3.0 V to 5.5 V supply range accepts both 3.3 V logic-level and 5 V regulated supplies.
Recommended
Battery-Powered IoT Sensor Node
The PIC12C509A-04E/P forms the low-power core of disposable or long-life IoT sensor nodes, where sleep current, cost, and pin count dominate over raw computational throughput. The integrated 4 MHz RC oscillator can be gated between active and sleep modes, and the watchdog timer with dedicated on-chip RC keeps duty cycle below 1 percent for multi-year coin-cell life. The 1.5 KB OTP accommodates simple application firmware for temperature, humidity, or contact sensing, and 6 I/O pins drive a piezo buzzer, LED, and I2C-attached sensor.
Recommended
Recommended Products Summary
Engineering reference data for PIC12C509A-04E/P — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC12F509-I/P | PIC12C509A-04/SN | PIC12C508A-04E/P | PIC12C509-04/P | PIC12C509A-04I/P |
|---|---|---|---|---|---|---|
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Package | 8-pin PDIP (P) | 8-pin PDIP - same | 8-pin SOIC - same pin count | 8-pin PDIP - same | 8-pin PDIP - same | 8-pin PDIP - same |
| Program Memory Type | OTP EPROM (1.5 KB) | Flash (1.5 KB, 100k E/W) | OTP EPROM (1.5 KB) - same | OTP EPROM (750 B) | OTP EPROM (1.5 KB) | OTP EPROM (1.5 KB) - same |
| Program Memory Size | 1.5 KB (1K x 12) | 1.5 KB | 1.5 KB | 750 B | 1.5 KB | 1.5 KB |
| RAM | 41 bytes | 41 bytes | 41 bytes | 25 bytes | 41 bytes | 41 bytes |
| I/O Pins | 6 | 6 | 6 | 6 | 6 | 6 |
| CPU Speed | 4 MHz | 4 MHz | 4 MHz | 4 MHz | 4 MHz | 4 MHz |
| Operating Temperature | -40 C to +125 C (Extended) | -40 C to +85 C (Industrial) | -40 C to +125 C (Extended) | -40 C to +125 C (Extended) | -40 C to +85 C (Industrial) | -40 C to +85 C (Industrial) |
Key Differentiators
- Extended -40C to +125C temperature grade as standard (vs PIC12C509A-04I/P)
- Through-hole PDIP package for hand prototyping and stress-relief applications (vs PIC12C509A-04/SN)
- Drop-in upgradeable to Flash via PIC12F509 (vs PIC12C508A-04E/P)
Design Notes
The PIC12C509A-04E/P uses one-time programmable (OTP) EPROM, so once the code-protection bit is set, the firmware cannot be changed. Always program a known-good image and verify with Microchip's MPLAB IDE + ICD before sealing the code-protection bit. For development or field-updatable designs, select the Flash-based PIC12F509 drop-in instead, which retains the same 8-pin PDIP pinout and 1.5 KB program memory but adds 100,000 erase/write cycles.
The PIC12C509A-04E/P operates from 3.0 V to 5.5 V. Bulk-decouple VDD with a 100 nF ceramic capacitor placed within 5 mm of pin 1, and add a 10 uF tantalum or aluminum polymer bulk capacitor at the PCB power-entry point. For battery-powered designs, the device draws a few hundred uA in active mode at 4 MHz and drops to a few uA in sleep mode - place the MCU in sleep between sensor samples to extend coin-cell life into the multi-year range.
Route the ICSP programming signals (GP0/GP1 data and clock, GP3/MCLR high-voltage) to a 6-pin header on the PCB even on production boards, so factory programming and field firmware updates remain possible without removing the MCU. Keep the ICSP traces short (under 50 mm) and avoid running them parallel to switching-power or motor-drive traces to prevent programming-voltage noise from corrupting writes. A 10 kohm pull-up on MCLR prevents spurious resets in electrically noisy environments.
GP3 on the PIC12C509A-04E/P is input-only and shares its pin with the MCLR reset function, so it cannot drive outputs. The remaining five I/O pins (GP0, GP1, GP2, GP4, GP5) are bidirectional. When driving LEDs or relays, add a flyback diode across any inductive load, and never exceed 25 mA source or sink per pin or 200 mA total across all I/O combined to stay within the package's thermal dissipation budget.
Compliance Information
RoHS and lead-free per Microchip product page. The "E" extended temperature grade (-40C to +125C) is not equivalent to AEC-Q100 automotive qualification; for AEC-Q100 applications use a -Q1 suffix variant such as the PIC12F509-E/SN or PIC16F18313-E/P.
