PIC12LC509A-04/SM - 8-bit OTP MCU, 1.5KB EPROM, 4MHz | Microchip
MPN: PIC12LC509A-04/SM ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $2.25 | $2.25 |
| 10 | $2.02 | $20.20 |
| 100 | $1.79 | $179.00 |
| 500 | $1.55 | $775.00 |
| 1,000 | $1.35 | $1,350.00 |
| 3,000 | $1.18 | $3,540.00 |
PIC12LC509A-04/SM Overview
What is an 8-bit OTP microcontroller? It is a small, fully-static CMOS processor that executes a fixed RISC instruction set from non-volatile one-time-programmable program memory. The PIC12LC509A belongs to the taxonomy: microcontroller -> embedded MCU -> 8-bit MCU -> PIC12 family -> PIC12C5xx OTP sub-family. Within a system hierarchy it sits below the application processor, handling glue logic, sensor I/O, and low-power control tasks where simplicity and pin count matter more than raw MIPS.
Key features of the PIC12LC509A include 33 single-word single-cycle instructions, a Power-On Reset (POR), a Device Reset Timer (DRT), a Watchdog Timer (WDT) with its own on-chip RC oscillator, programmable code protection, and 1,000,000 erase/write cycle endurance on EPROM. It executes instructions in 1 microsecond at 4 MHz and offers four oscillator options for system-clock flexibility.
Architecturally the PIC12LC509A uses a Harvard-style RISC core with separate program and data buses, which is why it can fetch an instruction and access data in a single cycle. The device draws very low operating current (typical I_dd in the low-mA range at full speed) and supports a wide operating voltage range from 2.5V up to 5.5V, enabling direct battery or 3.3V-rail operation in portable designs.
Typical applications include low-cost consumer appliances, sensor signal conditioning, simple motor and lighting controllers, automotive body modules, and standalone glue-logic replacements for discrete 555/74HC-based designs. It is also well suited to industrial control loops that require deterministic timing but tolerate 4 MHz throughput. Designers choose the PIC12LC509A when they need a proven PIC architecture in an 8-pin footprint with EPROM-based code storage.
When designing with this part, remember that OTP memory cannot be re-programmed in-circuit - the device must be programmed in a socket programmer before final assembly. Provide adequate decoupling (0.1 uF + bulk) close to Vdd, and configure the MCLR pin with a proper pull-up and, if desired, a manual reset switch.
This page synthesizes distributor pricing, drop-in same-package alternatives, and practical design notes that go beyond what is printed on the Microchip datasheet, helping engineers select, second-source, and deploy the PIC12LC509A-04/SM with confidence.
Drop-in alternatives for PIC12LC509A-04/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-04/SM (same form factor and footprint) — differing in Program Memory Size, Package, Instruction Set, Operating Temperature Range, Timers.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PIC12C509A-04/SM
✅ Drop-In✓ In Stock
$0.99 / Unit
View Datasheet →PIC12LC509A-04I/SM
✅ Drop-In✓ In Stock
$0.71 / Unit
View Datasheet →PIC12LC509AT-04/SM
✅ Drop-In✓ In Stock
$0.89 / Unit
View Datasheet →PIC12LC508A-04I/SN
✅ Drop-In ⚠️ 参数待验证✓ In Stock
$0.58 / Unit
View Datasheet →PIC12CE518-04E/SM
✅ Drop-In ⚠️ 参数待验证✓ In Stock
$1.6 / Unit
View Datasheet →PIC12C672-04/SM
✅ Drop-In✓ In Stock
$3.1 / Unit
View Datasheet →PIC12LC509A-04/SM Maximum Ratings & Electrical Characteristics
| Architecture | 8-bit RISC Harvard |
| Program Memory Type | OTP EPROM |
| Program Memory Size | 1.5 KB (1K x 12 words) |
| Data RAM | 41 bytes |
| Data EEPROM | None (OTP only) |
| Maximum CPU Frequency | 4 MHz |
| Instruction Execution Time | 1 us at 4 MHz |
| Instruction Set | 33 single-word instructions, single-cycle |
| I/O Pins | 6 |
| Timers | 1 x 8-bit TMR0 with 8-bit prescaler |
| Watchdog Timer | Yes (WDT with dedicated on-chip RC) |
| Power-On Reset | Yes (POR) |
| Device Reset Timer | Yes (DRT) |
| Supply Voltage Range | 2.5 V to 5.5 V |
| Operating Temperature Range | 0 C to +70 C (commercial) |
| Package | 8-pin SOIJ (SM), 0.209 in (5.30 mm) body width |
| Mounting Type | Surface Mount |
| Erase/Write Endurance | 1,000,000 cycles |
| Code Protection | Programmable |
| RoHS Status | Compliant |
PIC12LC509A-04/SM 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 / programming voltage |
| Pin 4 | GP2/T0CKI/INT — General-purpose I/O / TMR0 clock input / external interrupt |
| Pin 5 | GP1 — General-purpose bidirectional I/O |
| Pin 6 | GP0 — General-purpose bidirectional I/O |
| Pin 7 | VSS — Ground reference |
| Pin 8 | VDD — Positive supply voltage (2.5 V to 5.5 V) |
Typical Applications
PIC12LC509A-04/SM is suitable for 6 applications: Low-Cost Consumer Appliance Controller, Automotive Body Module (OTP code-stable nodes), Sensor Signal Conditioning and Threshold Logic, Simple Motor and Lighting Driver, Industrial Control Loop Glue Logic Replacement, Standalone Glue-Logic / 555 Replacement.
Low-Cost Consumer Appliance Controller
The PIC12LC509A-04/SM fits low-cost consumer appliance controllers because it offers 6 GPIO pins, 4 MHz deterministic instruction execution, and a 0.1 mA-class active current draw in an 8-pin SOIJ package. With 1.5 KB of OTP program memory and 33 single-cycle instructions, the device can implement timer-based wash cycles, simple keypad scanners, or LED-driving routines on a single die. The 2.5 V-5.5 V supply range lets designers reuse the part on either 3.3 V or 5 V rails without level translation, while the Power-On Reset and Watchdog Timer add the system-level robustness required by IEC 60730 household-appliance safety guidance. Compared with discrete 555/74HC solutions, a single PIC reduces BOM count and gives engineers firmware-driven feature flexibility.
Recommended
Automotive Body Module (OTP code-stable nodes)
The PIC12LC509A-04/SM is used in automotive body modules such as seat controllers, mirror adjusters, and simple lighting nodes where OTP memory locks code for the lifetime of the vehicle and prevents unauthorized firmware modification. Its 6 GPIO pins can directly drive small relays and read switches, while the on-chip Watchdog Timer with dedicated RC oscillator ensures recovery from lockups without external components. The 0 C to +70 C commercial grade suits cabin applications, but designers must select PIC12LC509AT or industrial-grade variants for under-hood environments. The 4 MHz deterministic 1 us instruction cycle keeps latency predictable for safety-critical debounce logic, and the 2.5 V-5.5 V supply tolerates cranking transients on the 12 V bus when paired with a pre-regulator.
Recommended
Sensor Signal Conditioning and Threshold Logic
In sensor signal conditioning applications, the PIC12LC509A-04/SM serves as the threshold-detection and pre-processing element next to a transducer, offloading low-level analog decisions from a more expensive main MCU. The 8-bit TMR0 with 8-bit prescaler generates precise sample intervals for thermistor, photodiode, or Hall-sensor pulse trains, while the WDT handles fault recovery on noisy industrial lines. Engineers use it to debounce mechanical switches, linearize NTC curves in software, and wake a higher-tier MCU only when an event exceeds a threshold - extending the system-level sleep current into the microamp range. The 8-pin SOIJ package allows direct PCB integration next to the sensor, reducing analog-loop trace length.
Recommended
Simple Motor and Lighting Driver
The PIC12LC509A-04/SM is suitable for simple brushed-DC motor speed/timing controllers and LED chaser lighting modules where 6 GPIO and 4 MHz throughput are sufficient. Each GPIO can source/sink roughly 25 mA, enough to drive a small logic-level MOSFET or low-current LED string directly via current-limit resistors. The 1 us instruction cycle supports software PWM up to a few kHz, enough for LED dimming and slow motor ramp profiles. Programmable code protection prevents reverse engineering of proprietary lighting patterns. Operating from a USB-style 5 V rail or 3.3 V LDO output, the part fits compact driver boards behind cabinetry or under furniture with minimal thermal concerns.
Recommended
Industrial Control Loop Glue Logic Replacement
Engineers replace discrete 555 timer and 74HC logic chains with the PIC12LC509A-04/SM in industrial control loops to consolidate timing, sequencing, and I/O conditioning into one programmable part. The 1.5 KB OTP holds PID-style setpoint logic, while the Watchdog Timer with on-chip RC keeps the node alive through EMI events typical of motor-control cabinets. The 0 C to +70 C commercial grade is adequate for sealed enclosures; specify the -I industrial variant when the PCB sits near heat sources. The 8-pin SOIJ footprint is mechanically drop-in compatible with SOIC, simplifying retrofits of legacy boards.
Recommended
Standalone Glue-Logic / 555 Replacement
As a drop-in replacement for 555/74HC-style discrete glue logic, the PIC12LC509A-04/SM cuts BOM count and adds firmware flexibility to designs that historically needed several timing ICs. A single part can implement a missing-edge detector, monostable, astable, or shift-register chain, freeing board space for analog stages. The 41 bytes of data RAM allow short buffer queues for protocol-bridging between two asynchronous bitstreams, while the 8-bit TMR0 handles deterministic bit timing. Designers migrating from 5 V legacy boards can keep the same supply rail, while 3.3 V systems use the same part directly thanks to the 2.5 V-5.5 V range.
Recommended
Recommended Products Summary
Engineering reference data for PIC12LC509A-04/SM — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC12C509A-04/SM | PIC12LC509A-04I/SM | PIC12LC509AT-04/SM | PIC12LC508A-04I/SN | PIC12CE518-04E/SM | PIC12C672-04/SM |
|---|---|---|---|---|---|---|---|
| Package | 8-pin SOIJ (SM) | 8-pin SOIJ (SM) - same | 8-pin SOIJ (SM) - same | 8-pin SOIJ (SM) - same | 8-pin SOIC (SN) - footprint compatible | 8-pin SOIJ (SM) - same | 8-pin SOIJ (SM) - same |
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Program Memory | 1.5 KB (1K x 12) OTP | 1.5 KB OTP | 1.5 KB OTP | 1.5 KB OTP | 768 B OTP | 768 B OTP + 16 B EEPROM | 3.5 KB (2K x 14) EPROM |
| Data RAM | 41 bytes | 41 bytes | 41 bytes | 41 bytes | 25 bytes | 25 bytes | 128 bytes |
| Max CPU Frequency | 4 MHz | 4 MHz | 4 MHz | 4 MHz | 4 MHz | 4 MHz | 4 MHz |
| Supply Voltage Range | 2.5 V to 5.5 V | 3.0 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 | 3.0 V to 5.5 V |
| Operating Temperature | 0 C to +70 C | 0 C to +70 C | -40 C to +85 C | 0 C to +70 C | -40 C to +85 C | -40 C to +85 C | 0 C to +70 C |
| I/O Pins | 6 | 6 | 6 | 6 | 6 | 6 | 6 |
| Unit Price (qty 1, USD, as of 2026-09-16) | $2.25 | $2.25 - $2.50 | $2.80 - $3.20 | $2.25 - $2.50 | $1.60 - $1.90 | $2.60 - $3.00 | $3.20 - $3.60 |
Key Differentiators
- Extended 2.5 V-5.5 V supply range (vs PIC12C509A-04/SM)
- Lowest unit-cost OTP option in 8-pin SOIJ (vs PIC12C672-04/SM)
- Industrial-grade sibling available with same die (vs PIC12LC509A-04I/SM)
Design Notes
The PIC12LC509A-04/SM supply range is 2.5 V-5.5 V. Place a 0.1 uF ceramic decoupling capacitor as close as possible to pin 8 (VDD), with a bulk 1-10 uF tantalum or aluminum on the same node. For battery applications below 3.0 V, the 'LC' variant is mandatory; substituting a standard 'C' version will brown-out the core. Estimated quiescent current at 4 MHz is in the low-mA range per Microchip datasheet curves; in sleep mode the part draws microamp-level current suitable for coin-cell duty.
OTP memory is one-time-programmable. Prototype firmware in a Flash sibling such as PIC12F509-I/SN or PIC12F629-I/SN before committing to the PIC12LC509A. Code-protect bits are independent of MCLR; locking the part without enabling code protection allows a third party to read back the OTP array. The MCLR pin (pin 3) doubles as VPP during programming - never tie it directly to VDD without a series resistor or pull-up that allows the programmer to overdrive it to ~13 V.
The 8-pin SOIJ footprint is pin-compatible with 8-pin SOIC land patterns, but verify the J-lead bend radius does not collide with adjacent components in dense layouts. Keep the oscillator traces (pins 1 and 2) short and guarded by a ground ring if you are using a crystal; for RC oscillator configurations add a small series resistor to limit crystal drive and avoid over-exciting low-power crystals. Provide a 10 kohm pull-up on MCLR if the pin is used as a reset input.
GPIO toggling at 4 MHz produces fast edges; route sensitive analog traces away from the GP0-GP5 lines and add a ground pour to reduce crosstalk. Each GPIO can source/sink roughly 25 mA, but the total package dissipation budget (typically 700-800 mW) limits simultaneous high-current drive; derate when more than two pins switch full load. Use the WDT with its dedicated on-chip RC oscillator to recover from software lockups without depending on the primary system clock.
Compliance Information
RoHS and lead-free status confirmed via Microchip product page. Not AEC-Q100 qualified; for automotive body ECUs consider the automotive-grade sibling if available. Halogen-free status not stated in the verified web data.
