PIC12LC508AT-04I/SM - 4MHz 8-Bit OTP MCU, 768B | Microchip
MPN: PIC12LC508AT-04I/SM ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $1.45 | $1.45 |
| 10 | $1.3 | $13.00 |
| 100 | $1.12 | $112.00 |
| 500 | $0.97 | $485.00 |
| 1,000 | $0.84 | $840.00 |
PIC12LC508AT-04I/SM Overview
An 8-bit microcontroller (MCU) is a single-chip computer that integrates a CPU, RAM, non-volatile program memory, and peripheral set on one die. The PIC12C family from Microchip uses a RISC-based Harvard architecture with a 12-bit instruction word and 8-bit data path; these parts target simple control tasks where cost, pin count, and deterministic interrupt response are more important than raw compute throughput. The 'LC' sub-family specifically trades higher speed for low-voltage operation (down to 3.0V) and reduced current consumption versus the standard PIC12C508A. The hypernym hierarchy: 8-bit microcontroller -> microcontroller -> embedded processor -> integrated circuit -> semiconductor.
Key features of the PIC12LC508AT-04I/SM include a programmable 8-bit timer/counter (TMR0) with an 8-bit prescaler, Watchdog Timer (WDT) with its own on-chip RC oscillator for reliable operation independent of the main clock, Power-On Reset (POR), Device Reset Timer (DRT), and selectable code protection to guard against unauthorized memory reads. The 6-bit general-purpose I/O is multiplexed with shared peripheral functions including GP2/T0CKI for the timer clock input. The device uses a serial in-circuit programming interface via GP1/GP0 pins, eliminating the need for a parallel programmer.
From an architecture perspective, the PIC12C5xx core executes most instructions in a single oscillator cycle (200 ns at 4 MHz), enabling responsive event handling. The 12-bit instruction width optimizes code density for bit-oriented and byte-oriented operations commonly used in control firmware. Internal 4 MHz RC oscillator accuracy is typically within ±1% over the industrial temperature range, removing the need for external crystal in cost-sensitive applications.
Typical applications for the PIC12LC508AT-04I/SM include low-power battery sensors, smart-card / token / disposable electronic devices, simple LED controllers, PWM fan controllers, and small appliance control boards. The 'I' suffix indicates industrial temperature range (-40°C to +85°C), making the part suitable for outdoor and automotive-cabin environments. The 'T' suffix denotes tape-and-reel packaging, and the 'SM' suffix specifies the SOIJ-8 surface-mount package (a J-lead variant of SOIC).\n
When designing with this part, note that OTP memory cannot be electrically erased—prototyping should be performed with the windowed JW variant or the pin-compatible PIC12F508 (Flash). Decoupling VDD with a 100 nF ceramic cap placed within 5 mm of the pin is recommended. For applications needing ADC, EEPROM, or more RAM, consider the PIC12F675 or PIC12CE518 upgrade paths.
This page synthesizes distributor stock data, parametric drop-in alternatives, and application guidance not collected in the manufacturer datasheet alone.
Drop-in alternatives for PIC12LC508AT-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 PIC12LC508AT-04I/SM (same form factor and footprint) — differing in Core Architecture, Instruction Set, Package, Program Memory Size, Program Memory Type.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PIC12C508A-04I/SM
✅ Drop-In✓ In Stock
$1.05 / Unit
View Datasheet →PIC12LC508A-04I/SM
✅ Drop-In✓ In Stock
$0.6144 / Unit
View Datasheet →PIC12F508-I/SM
✅ Drop-In📋 Reference alternative (not in catalog)
PIC12CE518-04I/SM
✅ Drop-In📋 Reference alternative (not in catalog)
PIC12F675-I/SM
✅ Drop-In📋 Reference alternative (not in catalog)
PIC12LC508AT-04I/SM Maximum Ratings & Electrical Characteristics
| Core Architecture | 8-bit PIC RISC (Harvard) |
| Series | PIC® 12C |
| Program Memory Type | OTP (One-Time Programmable) |
| Program Memory Size | 768 bytes (512 x 12 bits) |
| RAM Size | 25 bytes |
| Maximum Clock Speed | 4 MHz |
| I/O Pins | 6 |
| Supply Voltage (Vdd) | 3.0 V to 5.5 V |
| Timer Modules | 1 x 8-bit (TMR0 with 8-bit prescaler) |
| Watchdog Timer (WDT) | Yes (independent on-chip RC oscillator) |
| Power-On Reset (POR) | Yes |
| Code Protection | Programmable |
| Operating Temperature | -40 °C to +85 °C (Industrial, 'I' suffix) |
| Package | 8-pin SOIJ (5.30 mm width) |
| Mounting Type | Surface Mount |
| Packaging | Tape & Reel ('T' suffix) |
PIC12LC508AT-04I/SM Pin Configuration
| Pin 1 | VDD — Positive supply voltage (3.0 V–5.5 V) |
| Pin 2 | GP5/OSC1/CLKIN — General-purpose I/O / oscillator input / external clock input |
| Pin 3 | GP4/OSC2 — General-purpose I/O / oscillator output |
| Pin 4 | GP3/MCLR/VPP — General-purpose input / Master Clear reset (active low) / programming voltage |
| Pin 5 | GP2/T0CKI — General-purpose I/O / Timer0 clock input |
| Pin 6 | GP1 — General-purpose I/O / serial programming data |
| Pin 7 | GP0 — General-purpose I/O / serial programming clock |
| Pin 8 | VSS — Ground reference |
Typical Applications
PIC12LC508AT-04I/SM is suitable for 6 applications: Low-Power Battery Sensor Node, Smart Card / Disposable Electronics, Simple LED Lighting Controller, Small Appliance Control Board, PWM Fan Speed Controller, Automotive Cabin Sensor Module.
Low-Power Battery Sensor Node
The PIC12LC508AT-04I/SM is well-suited for battery-powered sensor nodes because of its low-voltage 'LC' family specification, which guarantees full 4 MHz operation down to 3.0 V—directly compatible with two fresh alkaline or NiMH cells. With 25 B RAM and 768 B OTP, the device can hold compact firmware for periodic ADC-free sampling of digital inputs (e.g., reed switches, thermistor comparators) and report via simple GPIO toggling. The integrated Watchdog Timer with independent RC oscillator lets the firmware recover from brownouts without external supervisor hardware. For sub-mA average current, the device spends most of its time in Sleep mode with TMR0 waking it; this is one of Microchip's lowest-cost low-voltage MCU options for disposable and remote-sensor applications. The 8-pin SOIJ also keeps PCB area minimal for coin-cell form factors.
Recommended
Smart Card / Disposable Electronics
The OTP program memory of PIC12LC508AT-04I/SM is ideally matched to disposable electronic products such as prepaid tokens, single-use access cards, or promotional giveaway gadgets, where the part must be inexpensive and firmware is finalized before volume production. The 768 B OTP holds small state machines that drive LEDs, buzzers, or simple LCD segments without needing runtime reprogramming. The 'LC' low-voltage operation extends battery life versus higher-voltage PIC12C508A when paired with 3 V lithium coin cells. Industrial temperature (-40 °C to +85 °C, 'I' suffix) supports outdoor or wallet-environment operation. The 6 GPIO are sufficient to drive a piezo buzzer, status LED, and a single tactile switch in a typical token-application circuit, with the SOIJ-8 package fitting inside credit-card-form-factor enclosures.
Recommended
Simple LED Lighting Controller
The PIC12LC508AT-04I/SM drives small LED lighting controllers, including decorative LED strings and indicator panels, where each GPIO bit directly controls an LED via current-limit resistor and the TMR0 module generates PWM modulation in software. The 4 MHz clock provides adequate PWM resolution at typical LED dimming frequencies (100 Hz to 1 kHz), and 25 B RAM easily handles 4-channel PWM state. Industrial temperature grade allows use in outdoor signage or refrigerated display cases. With 6 GPIO, the device can independently drive 6 LED channels or 3 RGB channels without external driver logic, and code protection prevents unauthorized firmware cloning. The SOIJ-8 SMD package supports automated assembly at sub-1 cm² PCB footprints, ideal for space-constrained decorative fixtures.
Recommended
Small Appliance Control Board
PIC12LC508AT-04I/SM integrates a programmable MCU into small household appliances such as fan controllers, hair dryers, and kitchen timers, where the 6 GPIO directly interface with tactile keypads, LED indicators, TRIAC trigger pins, and relay coils. The PIC RISC Harvard architecture executes most instructions in a single 200 ns cycle, so response latency to user button presses is imperceptible. The Watchdog Timer prevents firmware lockup from electrical noise generated by motor or TRIAC switching, and Power-On Reset guarantees a clean startup after power restoration. The 768 B OTP holds state-machine firmware for typical 8-state appliance cycles, with industrial temperature (-40 °C to +85 °C) supporting garage and unheated-storage environments.
Recommended
PWM Fan Speed Controller
For PC case fans, instrument-cooling fans, and low-power brushless DC fan controllers, the PIC12LC508AT-04I/SM delivers PWM fan-speed control using the TMR0 8-bit timer and software-based PWM output. The 4 MHz clock supports 25 kHz PWM at 8-bit resolution—above the audible band to eliminate whining noise from the fan motor. 6 GPIO are sufficient for tachometer input, PWM output, and fault LEDs. The Watchdog Timer independently recovers the controller if firmware hangs due to electrical transients from the motor. Industrial temperature rating ('I' suffix) supports computer-room and outdoor-cabinet installations. The SOIJ-8 footprint mounts directly inline with fan-header pin headers on compact fan-controller PCBs.
Recommended
Automotive Cabin Sensor Module
The industrial temperature range (-40 °C to +85 °C, 'I' suffix) of PIC12LC508AT-04I/SM makes it suitable for automotive cabin applications such as dome-light controllers, seat-occupancy indicator LEDs, and accessory-delay relays, where under-hood temperatures are not seen but wide thermal swings still occur. With 6 GPIO, the device reads a door-switch input, drives an LED indicator, and controls a relay coil—typical cabin-body-controller I/O. The PIC12C core's deterministic interrupt response (fixed instruction cycles) suits automotive latency requirements, and the SOIJ-8 surface-mount package withstands automotive PCB-level vibration. For under-hood applications requiring +125 °C, upgrade to the 'E' extended temperature variant instead. The 3.0 V minimum supply lets the device run from 12 V battery via a simple linear regulator.
Recommended
Recommended Products Summary
Engineering reference data for PIC12LC508AT-04I/SM — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC12C508A-04I/SM | PIC12LC508A-04I/SM | PIC12F508-I/SM | PIC12CE518-04I/SM | PIC12F675-I/SM |
|---|---|---|---|---|---|---|
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Package | 8-pin SOIJ | 8-pin SOIJ - same | 8-pin SOIJ - same | 8-pin SOIJ - same | 8-pin SOIJ - same | 8-pin SOIJ - same |
| Program Memory Type | OTP (768 B) | OTP (768 B) | OTP (768 B) | Flash (768 B) | OTP (768 B) + 16 B EEPROM | Flash (1 KB) |
| Supply Voltage | 3.0 V–5.5 V | 4.0 V–5.5 V | 3.0 V–5.5 V | 2.0 V–5.5 V | 3.0 V–5.5 V | 2.0 V–5.5 V |
| Maximum Clock Speed | 4 MHz | 4 MHz | 4 MHz | 4 MHz | 4 MHz | 20 MHz |
| RAM Size | 25 bytes | 25 bytes | 25 bytes | 25 bytes | 25 bytes | 64 bytes |
| I/O Pins | 6 | 6 | 6 | 6 | 6 | 6 |
| ADC | No | No | No | No | No | Yes (10-bit) |
| Internal EEPROM / Calibration | No | No | No | No | Yes (16 B EEPROM, calibrated OSC) | Yes (128 B EEPROM, calibrated OSC) |
| Operating Temperature | -40 °C to +85 °C | -40 °C to +85 °C | -40 °C to +85 °C | -40 °C to +85 °C | -40 °C to +85 °C | -40 °C to +85 °C |
Key Differentiators
- Low-voltage ('LC') family operation down to 3.0 V (vs PIC12C508A-04I/SM)
- Tape-and-reel packaging for high-volume SMD assembly (vs PIC12LC508A-04I/SM)
- Industrial temperature grade (-40 °C to +85 °C) for outdoor/automotive cabin use (vs PIC12C508A-04/SM (commercial 0 °C to +70 °C))
- Drop-in pin compatibility with Flash-based PIC12F508 family (vs PIC12C508A-04I/SM)
Design Notes
The PIC12LC508AT-04I/SM requires a single 3.0 V–5.5 V supply on VDD (pin 1); place a 100 nF ceramic decoupling capacitor within 5 mm of the VDD pin to suppress switching transients generated by the internal oscillator and I/O toggling. The internal 4 MHz RC oscillator accuracy is typically ±1% over the industrial temperature range, eliminating the need for an external crystal in most cost-sensitive designs. For designs sensitive to frequency drift, switch to a low-power external crystal on OSC1/OSC2 (GP5/GP4), but note that those pins lose their GPIO function. The Power-On Reset (POR) circuit holds the device in reset until VDD rises above the POR threshold (~2.0 V typical), so no external reset IC is needed for slowly rising supplies.
OTP program memory cannot be electrically erased or rewritten—once programmed, the device is fixed. Prototyping must use either a windowed JW-package PIC12C508A or the pin-compatible Flash-based PIC12F508. The GP3/MCLR/VPP pin (pin 4) is shared between general-purpose input (input-only on this part) and the Master Clear reset function; if MCLR is enabled in the configuration bits, this pin cannot be used as a digital input and must be pulled high through a 10 kΩ resistor. For low-voltage designs running at 3.0 V–3.3 V, ensure the 'LC' variant is used—standard PIC12C508A is specified only down to 4.0 V and may exhibit timing violations below that.
The 8-pin SOIJ ('SM') package has J-leads on a 5.30 mm body width with 1.27 mm pitch; standard SOIC-8 land patterns are compatible, but the SOIJ body is wider than SOIC, so verify keep-out zones for adjacent components. A ground pour on the top or bottom layer directly under the device is recommended to reduce EMI and provide thermal relief. Place the ICSP programming footprint (VPP, ICSPCLK, ICSPDAT routed to test points or a 6-pin header) so that production programming can be performed without removing the device from the board. For tape-and-reel placement, the package orientation matches JEDEC SOIC-8 standards—no special tooling required.
Long GPIO traces (>50 mm) should be series-terminated with 100 Ω to dampen ringing from the device's edge rates (~10 ns). The PIC12C5xx GPIO drive strength is approximately 25 mA source/sink, sufficient for direct LED drive, but for high-speed signals or long cable interfaces, add external buffers. MCLR (pin 4) is sensitive to noise below VDD/2; route this trace away from switching signals or add a 100 nF bypass capacitor close to the MCLR pin if it is enabled. The Watchdog Timer uses an independent on-chip RC oscillator, so WDT timeouts remain accurate even if the main system clock fails—a significant reliability advantage over microcontrollers with WDT tied to the system clock.
Compliance Information
Compliance status not stated in the verified web data; consult Microchip's product compliance portal at microchip.com/compliance or your distributor for the current RoHS/REACH/AEC-Q100 certificate as of 2026-09-16. The SOIJ-8 package suffix historically denoted leaded parts, but modern production lots are typically RoHS-compliant—verify against shipped-date documentation.
