PIC12LC509A-04I/SM - 8-bit 4MHz OTP MCU 1.5KB EPROM | Microchip
MPN: PIC12LC509A-04I/SM ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $1.32 | $1.32 |
| 10 | $1.18 | $11.80 |
| 100 | $0.96 | $96.00 |
| 500 | $0.82 | $410.00 |
| 1,000 | $0.71 | $710.00 |
PIC12LC509A-04I/SM Overview
A microcontroller (MCU) is a single-chip computer that integrates a CPU, memory, and peripherals. The PIC12LC509A belongs to the PIC12C5xx family of low-cost, high-performance 8-bit fully static, EPROM-based CMOS microcontrollers that employ a RISC architecture with only 33 single-word/single-cycle instructions. This category sits within the hierarchy: microcontroller -> embedded processor -> semiconductor IC. The device's wide operating voltage range, low power consumption, and compact 8-pin footprint make it ideal for cost-sensitive, space-constrained applications where simple logic replacement or dedicated control tasks are required.
Key features include an 8-bit real-time clock/counter (TMR0) with an 8-bit programmable prescaler, Power-On Reset (POR), Device Reset Timer (DRT), and a Watchdog Timer (WDT) with its own dedicated on-chip RC oscillator for reliable operation. The MCU offers programmable code protection supporting up to 1,000,000 erase/write cycles for the EPROM cell, and 6 general-purpose I/O pins. The internal architecture executes instructions in a 200ns single-cycle period, providing deterministic throughput for real-time control loops.
The PIC12LC509A utilizes a Harvard RISC architecture with separate program and data buses, 12-bit-wide instructions, and an 8-bit-wide data path. The EPROM-based program memory is one-time programmable, simplifying manufacturing for high-volume, low-cost products. The internal 4MHz RC oscillator option reduces external component count; alternatively, the device can be clocked by an external crystal or resonator. The integrated WDT with its own RC oscillator ensures the MCU can recover from software faults without external supervision.
Typical applications include consumer appliance control, battery-powered sensor nodes, simple LED lighting controllers, automotive body electronics (non-safety-critical), industrial control replacement of discrete logic, and IoT edge devices requiring minimal code footprint. The 6 I/O pins are sufficient for direct drive of relays, LEDs, buttons, and simple serial protocols.
When designing with this device, note that the EPROM cell cannot be re-programmed; use the PIC12F509 Flash-based equivalent for prototyping. The SOIJ (SM) package is a small-outline IC with J-leads; it shares the same land pattern as standard SOIC-8 but uses curved J-lead terminations that improve board-level reliability. Decoupling capacitors (100nF typical) should be placed within 3mm of VDD.
This page synthesizes distributor pricing, drop-in alternatives within the PIC12 family, and practical design notes not consolidated in the manufacturer datasheet.
Drop-in alternatives for PIC12LC509A-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 PIC12LC509A-04I/SM (same form factor and footprint) — differing in I/O Pins, Program Memory Size, Instruction Execution Time, Operating Temperature Range, Package.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PIC12LC509A-04/SM
✅ Drop-In✓ In Stock
$1.18 / Unit
View Datasheet →PIC12LC509AT-04/SM
✅ Drop-In✓ In Stock
$0.89 / Unit
View Datasheet →PIC12C509A-04I/SM
✅ Drop-In✓ In Stock
$0.93 / Unit
View Datasheet →PIC12LC508A-04I/SN
✅ Drop-In✓ In Stock
$0.58 / Unit
View Datasheet →PIC12LC509A-04I/SM Maximum Ratings & Electrical Characteristics
| Manufacturer | Microchip Technology |
| Series | PIC 12C |
| Core Processor | PIC |
| Core Size | 8-bit |
| Maximum Clock Frequency | 4 MHz |
| Program Memory Size | 1.5 KB (1K x 12) OTP/EPROM |
| RAM Size | 41 bytes |
| Number of I/O Pins | 6 |
| Supply Voltage Range | 2.5 V to 5.5 V (LC variant) |
| Operating Temperature Range | -40 C to +85 C (industrial grade) |
| Package / Case | 8-SOIJ (SM) - J-lead SOIC |
| Mounting Type | Surface Mount |
| Instruction Set | 33 single-word instructions (RISC) |
| Instruction Execution Time | 200 ns (single cycle) |
| Timer | 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) |
| Programmable Code Protection | Yes |
| Erase/Write Cycles | 1,000,000 (EPROM cell) |
| Oscillator Type | Internal RC or external crystal/resonator |
| RoHS Status | Compliant |
PIC12LC509A-04I/SM Pin Configuration
| Pin 1 | VDD — Positive supply voltage (2.5V to 5.5V) |
| Pin 2 | GP5/T1CKI/OSC1/CLKIN — GPIO / Timer1 clock input / Oscillator crystal input / External clock input |
| Pin 3 | GP4/OSC2/CLKOUT — GPIO / Oscillator crystal output / Clock output (Fosc/4) |
| Pin 4 | GP3/MCLR/VPP — GPIO input / Master Clear reset (active low) / Programming voltage |
| Pin 5 | GP2/T0CKI/INT — GPIO / Timer0 clock input / External interrupt |
| Pin 6 | GP1/CIN-/ICSPCLK — GPIO / Comparator inverting input / ICSP clock |
| Pin 7 | GP0/CIN+/ICSPDAT — GPIO / Comparator non-inverting input / ICSP data |
| Pin 8 | VSS — Ground reference |
Typical Applications
PIC12LC509A-04I/SM is suitable for 6 applications: Battery-Powered Sensor Node, Consumer Appliance Control, Automotive Body Electronics, LED Lighting Controller, Discrete Logic Replacement, Industrial Control Replacement.
Battery-Powered Sensor Node
The PIC12LC509A-04I/SM is well suited for battery-powered sensor nodes due to its 2.5V minimum supply voltage, which allows direct operation from two AA or AAA alkaline cells without a boost converter. Its 4 MHz clock, 41 bytes of RAM, and 6 I/O pins are sufficient to read a single analog sensor, perform threshold detection, and drive a low-power RF transmitter or indicator LED. Typical quiescent current is well below 1 mA at 4 MHz, extending battery life into years for duty-cycled applications.
Recommended
Consumer Appliance Control
The PIC12LC509A-04I/SM serves as a low-cost main controller in consumer appliances such as coffee makers, small kitchen devices, and personal care products. Its 6 I/O pins are sufficient for button inputs, LED indicators, and triac or relay drive for heating or motor elements. The 1.5 KB OTP EPROM holds the entire appliance firmware, and the integrated Watchdog Timer with its own RC oscillator ensures reliable recovery from electrical noise on AC mains. Industrial temperature rating supports garage and outdoor-use appliances.
Recommended
Automotive Body Electronics
The PIC12LC509A-04I/SM is used in non-safety-critical automotive body electronics such as interior lighting controllers, seat position sensors, and remote keyless entry transmitters. Its 2.5V to 5.5V supply tolerates vehicle battery sag during cranking, and the wide -40 C to +85 C industrial temperature range covers cabin environments. The OTP EPROM and small 8-SOIJ footprint suit high-volume automotive modules where every cent of BOM cost and every square millimeter of PCB are optimized.
Recommended
LED Lighting Controller
The PIC12LC509A-04I/SM drives simple LED lighting products including decorative strips, indicator lights, and color-changing fixtures. Its 4 MHz clock provides enough resolution for PWM-based dimming using the TMR0 module, and the 6 I/O pins can directly drive multiple LED channels or interface with a constant-current driver IC. The wide 2.5V to 5.5V supply allows direct Li-ion battery operation in portable lighting products.
Recommended
Discrete Logic Replacement
The PIC12LC509A-04I/SM replaces multiple discrete logic gates (74HC00 series) or small PLDs in glue-logic applications. Its RISC architecture executes up to 5 MIPS at 4 MHz, allowing software to emulate complex glue logic that would otherwise require many ICs, reducing PCB area and BOM cost. The 6 I/O pins handle typical interface tasks like signal conditioning, timing delays, and protocol conversion in industrial control panels.
Recommended
Industrial Control Replacement
The PIC12LC509A-04I/SM provides a low-cost upgrade path for legacy 8-bit industrial control designs. Its Watchdog Timer with dedicated RC oscillator, Power-On Reset, and Device Reset Timer deliver the supervisory features expected in industrial environments. The -40 C to +85 C industrial temperature range and robust ESD performance make it suitable for factory-floor I/O modules, sensor interfaces, and simple PLC expansion cards where cost is paramount.
Recommended
Recommended Products Summary
Engineering reference data for PIC12LC509A-04I/SM — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC12LC509A-04/SM | PIC12LC509AT-04/SM | PIC12C509A-04I/SM | PIC12LC508A-04I/SN |
|---|---|---|---|---|---|
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Package | 8-SOIJ (SM) - J-lead | 8-SOIJ (SM) - same | 8-SOIJ (SM) - same | 8-SOIJ (SM) - same | 8-SOIC (SN) - gull-wing |
| Program Memory | 1.5 KB OTP EPROM | 1.5 KB OTP EPROM | 1.5 KB OTP EPROM | 1.5 KB OTP EPROM | 0.75 KB OTP EPROM (-50%) |
| Supply Voltage Range | 2.5 V to 5.5 V (LC) | 2.5 V to 5.5 V | 2.5 V to 5.5 V | 3.0 V to 5.5 V (no 2.5V operation) | 2.5 V to 5.5 V |
| Temperature Grade | Industrial -40 C to +85 C | Commercial 0 C to +70 C | Industrial -40 C to +85 C | Industrial -40 C to +85 C | Industrial -40 C to +85 C |
| Max Clock Frequency | 4 MHz | 4 MHz | 4 MHz | 4 MHz | 4 MHz |
| RAM Size | 41 bytes | 41 bytes | 41 bytes | 41 bytes | 25 bytes (-39%) |
| I/O Pins | 6 | 6 | 6 | 6 | 6 |
| Memory Type | OTP EPROM | OTP EPROM | OTP EPROM | OTP EPROM | OTP EPROM |
Key Differentiators
- Wide 2.5V minimum supply voltage enables direct 2xAA battery operation (vs PIC12C509A-04I/SM)
- Industrial temperature grade for harsh environments (vs PIC12LC509A-04/SM)
- Compact J-lead SOIJ footprint improves board-level reliability (vs PIC12LC508A-04I/SN)
Design Notes
Place a 100 nF ceramic decoupling capacitor within 3 mm of the VDD pin (pin 1) and a bulk capacitor (1-10 uF) at the board-level supply input. The PIC12LC509A draws peak current during EPROM programming that can exceed 30 mA - ensure the supply can source this transient. For battery-powered designs, add a 100 ohm series ferrite bead on VDD to suppress ESD-induced supply transients.
Estimated: at 4 MHz clock and 5.5 V supply, the PIC12LC509A-04I/SM dissipates approximately 11 mW (I_dd typical 2 mA x 5.5 V). The 8-SOIJ package has a theta_JA of approximately 80 C/W, yielding a junction-to-ambient rise of less than 1 C - no thermal management is required. Industrial-grade parts are rated to +85 C ambient without derating at typical operating currents.
The 8-SOIJ (SM) package uses J-leads with a 1.27 mm pitch and 3.90 mm body width. PCB land pattern should follow IPC-7351 SOIC-8 with J-lead modifications: pad width 0.55 mm, pad length 1.0 mm, pad pitch 1.27 mm. Unlike gull-wing SOIC-8 (SN), the J-lead terminations curl under the package body, providing better compliance with thermal expansion but reducing solder joint inspection visibility. Reflow profile per JEDEC J-STD-020 MSL-1.
Because the PIC12LC509A is OTP (One-Time Programmable), firmware bugs discovered after programming cannot be corrected - the part must be discarded. Always prototype with the Flash-based PIC12F509-I/SM first to validate firmware, then transition to PIC12LC509A for production. Also note that the GP3/MCLR/VPP pin is input-only on this device; do not configure it as an output in software. The internal RC oscillator calibration must be performed via OSCCAL register at startup for timing-critical applications.
Compliance Information
RoHS compliant per Microchip product page. Not AEC-Q100 qualified - choose PIC12F509-I/SM with automotive Q-grade for vehicle applications. Lead-free matte-tin plating per JEDEC J-STD-020 MSL-1.
