PIC12LC509A-04I/P - 8-bit 4MHz OTP MCU, 1.5KB | Microchip
MPN: PIC12LC509A-04I/P β Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $1.65 | $1.65 |
| 10 | $1.49 | $14.90 |
| 100 | $1.32 | $132.00 |
| 500 | $1.18 | $590.00 |
| 1,000 | $1.05 | $1,050.00 |
| 3,000 | $0.94 | $2,820.00 |
PIC12LC509A-04I/P Overview
An 8-bit microcontroller (MCU) is a single-chip processor that integrates a CPU, memory, and peripherals onto one silicon die. The PIC12C5xx family belongs to the broader PIC microcontroller hierarchy: 8-bit MCU -> microcontroller -> embedded processor -> semiconductor. These MCUs use a RISC (Reduced Instruction Set Computer) architecture that prioritizes a small, fixed-length instruction set for deterministic execution, making them well-suited for cost-sensitive real-time control applications where predictability matters more than raw computational throughput.
Key features include a hardware 8-bit timer/counter (TMR0) with programmable prescaler, an on-chip Watchdog Timer (WDT) backed by its own dedicated RC oscillator for reliable operation independent of the main clock, Power-On Reset (POR), Device Reset Timer (DRT), and programmable code protection. The device also supports in-circuit serial programming (ICSP) via two pins, enabling firmware updates without removing the part from the board.
The architecture combines a Harvard-style separated program/data bus with a 12-bit-wide instruction word, which is wider than typical 8-bit data to embed literal operands and reduce fetch count. The LC suffix designates the low-voltage CMOS process, allowing reliable operation down to 2.5V for battery-powered designs where a standard PIC12C509A (4.0V-5.5V only) would not function.
Typical applications include appliance control boards, automotive sub-system modules, industrial sensor interfaces, battery-powered smart sensors, security system peripherals, and general-purpose logic replacement. Its 8-pin footprint makes it ideal for space-constrained retrofits and cost-down conversions from discrete logic.
When designing with this MCU, ensure the MCLR pin is pulled high through a proper resistor-capacitor network and provide adequate decoupling (100nF) on VDD. Programming voltage on the GP0/GP1 ICSP pins must respect the absolute maximum ratings to avoid damaging the part during repeated development cycles.
This page synthesizes distributor pricing, drop-in alternatives, application circuits, and practical design notes that go beyond what the manufacturer datasheet alone provides, organized specifically for engineering selection and procurement workflows.
Drop-in alternatives for PIC12LC509A-04I/P β same package, pin-to-pin compatible. Different-package parts requiring PCB rework are excluded.
Quick Comparison Tool β Select alternative parts for side-by-side comparison:
PIC12C509A-04I/P
β Drop-Inπ Reference alternative (not in catalog)
PIC12LC509A-04E/P
β Drop-Inπ Reference alternative (not in catalog)
PIC12C509A-04/P
β Drop-Inπ Reference alternative (not in catalog)
PIC12LC509A-04I/P Maximum Ratings & Electrical Characteristics
| Core Processor | PIC |
| Core Size | 8-Bit |
| Maximum Clock Speed | 4 MHz |
| Program Memory Size | 1.5 KB (1K x 12) OTP |
| 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, 'I' suffix) |
| Package | 8-PDIP (0.300 inch / 7.62 mm) |
| Instruction Set | 33 single-word/single-cycle instructions |
| Instruction Execution Time | 200 ns @ 4 MHz |
| Timer/Counters | 1 x 8-bit TMR0 with programmable prescaler |
| Watchdog Timer | Yes, dedicated on-chip RC oscillator |
| Power-On Reset (POR) | Yes |
| Device Reset Timer (DRT) | Yes |
| Code Protection | Programmable |
| ICSP (In-Circuit Serial Programming) | Yes (via GP0/GP1) |
| Program Memory Endurance | 1,000,000 erase/write cycles |
| Mounting Type | Through-Hole |
| RoHS Status | Compliant |
PIC12LC509A-04I/P Pin Configuration
| Pin 1 | VDD β Positive supply voltage (2.5V-5.5V) |
| Pin 2 | GP5/OSC1/CLKIN β GPIO 5 / Oscillator input / External clock input |
| Pin 3 | GP4/OSC2/CLKOUT β GPIO 4 / Oscillator output / Clock output |
| Pin 4 | GP3/MCLR/VPP β GPIO 3 / Master Clear (Reset) input / Programming voltage |
| Pin 5 | GP2/T0CKI/INT/COUT β GPIO 2 / Timer0 clock input / External interrupt / Comparator output |
| Pin 6 | GP1/CIN-/ICSPCLK β GPIO 1 / Comparator inverting / ICSP clock |
| Pin 7 | GP0/CIN+/ICSPDAT β GPIO 0 / Comparator non-inverting / ICSP data |
| Pin 8 | VSS β Ground reference |
Typical Applications
PIC12LC509A-04I/P is suitable for 6 applications: Battery-Powered Sensor Node Controller, Automotive Sub-System Module Controller, Appliance Control Board Replacement, Cost-Down Logic Replacement / Glue Logic, Security System Peripheral Controller, Educational / Hobbyist Microcontroller Platform.
Battery-Powered Sensor Node Controller
The PIC12LC509A-04I/P's 2.5V minimum supply enables direct operation from a single 3V CR2032 or two AA alkaline cells down to their end-of-life voltage, eliminating boost converters. Its 4MHz maximum clock and 200ns instruction execution let it poll sensors, run control loops, and enter sleep mode within strict energy budgets. The 41-byte RAM accommodates small state buffers for duty-cycled wireless or wired sensor nodes in environmental monitoring and IoT edge devices where 6 GPIO suffice for SPI/I2C bit-banging or simple LED/HMI control.
Recommended
Automotive Sub-System Module Controller
The PIC12LC509A-04I/P is used in non-safety automotive sub-systems where its industrial -40C to +85C temperature grade and automotive-rated supply tolerance meet cabin and under-hood sensor requirements. Its 6 GPIO can drive relay coils, read switches, and interface LIN-bus transceivers at bit-banged rates, while the dedicated WDT with its own RC oscillator ensures recovery from software lockups. The 1.5KB OTP provides sufficient headroom for state-machine control firmware in lighting, accessory, and body-electronics modules.
Recommended
Appliance Control Board Replacement
In white-goods and small appliance controls, the PIC12LC509A-04I/P replaces legacy 8-bit discrete-logic boards by integrating timing, sequencing, and user-input handling in one chip. Its 8-bit TMR0 with programmable prescaler drives wash-cycle, defrost, and timer functions deterministically, while 6 GPIO drive triac interfaces, read keypads, and control indicator LEDs. The PIC RISC architecture's deterministic 200ns instruction cycle keeps real-time loops jitter-free - critical for zero-cross triac switching that minimizes EMI in motor and heater loads.
Recommended
Cost-Down Logic Replacement / Glue Logic
When 7400-series discrete logic gates, timers (555), or shift registers would require multiple packages, the PIC12LC509A-04I/P consolidates equivalent functionality into a single 8-pin MCU costing under $1 in volume. Engineers port a small state machine into 1.5KB of OTP, reducing PCB area and BOM count. Common replacements include one-shots, monostables, sequence detectors, and simple protocol converters where the PIC's 4MHz instruction rate is more than adequate for ms-scale timing requirements.
Recommended
Security System Peripheral Controller
Peripheral devices in security panels - such as remote keypads, PIR-sensor interface boards, and low-power wireless receiver modules - use the PIC12LC509A-04I/P for local I/O handling and tamper detection. Its hardware watchdog timer, power-on reset, and code protection together provide the security primitives required to resist firmware extraction and lockup recovery. The 8-pin PDIP footprint and low pin count suit compact PCB layouts inside sensor housings.
Recommended
Educational / Hobbyist Microcontroller Platform
The PIC12LC509A-04I/P is a popular teaching platform for first-time embedded programmers because its 8-pin PDIP through-hole form factor fits standard breadboards and its 33-instruction RISC architecture is easy to learn. Educational labs use it to teach timer interrupts, GPIO bit manipulation, and watchdog reset behavior without requiring surface-mount soldering. Its low cost (under $2 in unit quantities) and broad hobbyist ecosystem of PIC programmers, ICD debuggers, and example code make it a staple in microcontroller training.
Recommended
Recommended Products Summary
Engineering reference data for PIC12LC509A-04I/P β comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC12C509A-04I/P | PIC12LC509A-04I/SM | PIC12LC509A-04E/P | PIC12C509A-04/P | PIC12C509A-04I/JW |
|---|---|---|---|---|---|---|
| Package | 8-PDIP | 8-PDIP - same | 8-SOIJ - different (SMT) | 8-PDIP - same | 8-PDIP - same | 8-CDIP (windowed) - different |
| 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 OTP | 1.5 KB OTP | 1.5 KB OTP | 1.5 KB EPROM |
| Max Clock Speed | 4 MHz | 4 MHz | 4 MHz | 4 MHz | 4 MHz | 4 MHz |
| Supply Voltage Range | 2.5 V to 5.5 V | 4.0 V to 5.5 V | 2.5 V to 5.5 V | 2.5 V to 5.5 V | 4.0 V to 5.5 V | 4.0 V to 5.5 V |
| Operating Temperature | -40 C to +85 C (I grade) | -40 C to +85 C | -40 C to +85 C | -40 C to +125 C (E grade) | 0 C to +70 C (commercial) | -40 C to +85 C |
| I/O Pins | 6 | 6 | 6 | 6 | 6 | 6 |
| Unit Price (qty 1) | $1.65 | $1.55 | $1.62 | $1.80 | $1.45 | $14.50 (windowed, prototype) |
Key Differentiators
- Wider low-voltage supply range than PIC12C509A (vs PIC12C509A-04I/P)
- Extended temperature grade option (E suffix) (vs PIC12LC509A-04I/P (industrial -40 to +85C))
- OTP memory in PDIP for low-cost prototyping (vs PIC12F509-I/P (Flash, 8-PDIP))
Design Notes
Estimated: The PIC12LC509A-04I/P typical active current at 4MHz/5V is ~2.0 mA and at 2.5V/32kHz (LF mode) drops to ~14 uA. Place a 100nF ceramic decoupling capacitor as close as possible to the VDD pin (pin 1) with a ground return via the shortest possible path to VSS (pin 8). For battery applications, switch to the internal 32.768 kHz LF oscillator and use sleep mode aggressively; this can reduce average current below 1 uA in duty-cycled sensor designs. The WDT has its own RC oscillator and continues running in sleep - enable it to wake the MCU from sleep on overflow.
The 8-PDIP through-hole footprint is 0.300 inch (7.62 mm) row spacing with 0.100 inch (2.54 mm) pin pitch - same as the standard 7400-series DIP. Route the MCLR/VPP pin (pin 4) away from high-frequency switching nodes to avoid spurious resets; a 10k pull-up to VDD plus a 100nF cap to ground forms the standard reset network. Place the crystal or resonator close to OSC1/OSC2 (pins 2/3) and guard the traces with a grounded copper pour to minimize EMI coupling. When using ICSP, dedicate the GP0/GP1 pins and isolate them from heavy loads so programming does not conflict with application circuitry.
Three common mistakes: (1) Assuming the LC and C variants are interchangeable below 4.0V - the PIC12C509A will fail to execute below 4.0V; use the LC variant explicitly. (2) Forgetting to disable the WDT in software or hardware config bits - if the WDT overflows in development, the MCU resets unexpectedly and looks like a code bug. (3) Programming OTP parts in-circuit without proper VPP isolation - the MCLR/VPP pin must be able to rise to ~13V during ICSP programming, and any external circuitry that clamps this pin below 13V will prevent programming.
Keep analog and digital grounds separated if the design interfaces with the on-chip comparator via GP0/GP1 - the datasheet recommends a star-ground configuration with the MCU VSS pin as the single tie-point. For RC oscillator mode (cheapest, lowest power), the OSC1 pin is the only analog concern; bypass it from high-current switching. In noisy environments, place a 4.7k pull-up on MCLR and a 100nF cap to ground directly at the pin - the rise time of MCLR determines the Power-On Reset behavior.
Compliance Information
RoHS compliant per DigiKey product listing. Industrial temperature grade (-40C to +85C) but not AEC-Q100 qualified - for AEC-Q100 automotive applications, Microchip recommends PIC12F615-I/P or PIC12HV615-I/P.
