PIC12C508-04I/SM - 4MHz 8-bit OTP MCU 8-SOIJ | Microchip
MPN: PIC12C508-04I/SM ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $1.85 | $1.85 |
| 10 | $1.66 | $16.60 |
| 100 | $1.48 | $148.00 |
| 500 | $1.32 | $660.00 |
| 1,000 | $1.18 | $1,180.00 |
PIC12C508-04I/SM Overview
An 8-bit microcontroller (MCU) is a small, low-cost computer-on-a-chip that integrates a CPU, memory, and I/O peripherals onto a single silicon die. Within the semiconductor hierarchy, an MCU sits under the broader category of microcontrollers, which themselves fall under Integrated Circuits > Logic ICs. The PIC12C5xx family specifically belongs to Microchip's PIC® (Peripheral Interface Controller) architecture, employing a RISC design with only 33 single-word/single-cycle instructions. This instruction simplicity is a defining feature that reduces development time and allows the device to deliver roughly 2:1 code compression versus competing 8-bit MCUs in its class. The "C" in PIC12C508 denotes the EPROM/OTP (one-time programmable) program memory variant, distinguishing it from later flash-based "F" revisions.
Key features of the PIC12C508-04I/SM include 25 bytes of RAM, 6 general-purpose I/O pins, a 4 MHz internal/external oscillator option, and an industrial temperature range of -40°C to +85°C. The "-04" suffix denotes the 4 MHz oscillator speed grade, while "I" indicates industrial temperature grading and "SM" is the 8-SOIJ (Small Outline IC, J-leaded) surface-mount package. The device is fully static, allowing the clock to be stopped without losing register state, and supports a wide operating voltage range of 2.5V to 5.5V, making it tolerant of both 3.3V and 5V logic rails.
Technically, the PIC12C508-04I/SM uses a 12-bit instruction word and a 2-stage pipeline that fetches the next instruction while executing the current one, achieving effective throughput of approximately 4 MIPS at 4 MHz. Its Harvard architecture separates program and data memory, eliminating bus contention and improving deterministic interrupt response. The device also features a watchdog timer, power-on reset, brown-out detect (on selected revisions), and a precision 4 MHz RC oscillator option that allows operation without external crystals, saving both board space and BOM cost.
Typical applications include low-cost consumer electronics, automotive body controllers, simple sensor interfaces, hobbyist and educational projects, and 8-pin appliances such as LED controllers and battery chargers. The 8-pin footprint is particularly valuable where PCB real estate is severely constrained.
When designing with this device, note that OTP memory cannot be reprogrammed, so firmware must be verified before committing to production units. Decoupling capacitors (100 nF) should be placed within a few millimeters of the VDD pin, and unused I/O pins should be configured as outputs to minimize current consumption.
This page synthesizes distributor pricing, drop-in-compatible alternatives, and practical design notes from the Microchip datasheet that are not aggregated on any single distributor product page.
Drop-in alternatives for PIC12C508-04I/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 PIC12C508-04I/SM (same form factor and footprint) — differing in Instruction Set, Mounting Type, Program Memory Size, Program Memory Type, RoHS Status.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PIC12C508A-04I/SM
✅ Drop-In✓ In Stock
$1.05 / Unit
View Datasheet →PIC12C508-04/SM
✅ Drop-In📋 Reference alternative (not in catalog)
PIC12C508A-04/SM
✅ Drop-In✓ In Stock
$1.18 / Unit
View Datasheet →PIC12C508T-04I/SM
✅ Drop-In📋 Reference alternative (not in catalog)
PIC12C508T-04E/SM
✅ Drop-In✓ In Stock
$0.98 / Unit
View Datasheet →PIC12C508-04I/SM Maximum Ratings & Electrical Characteristics
| Program Memory Type | EPROM/OTP |
| Program Memory Size | 768 B (512 x 12) |
| Data RAM | 25 B |
| CPU Architecture | 8-bit PIC RISC |
| Instruction Set | 33 single-word/single-cycle instructions |
| Maximum CPU Speed | 4 MHz |
| Operating Voltage Range | 2.5 V to 5.5 V |
| I/O Pins | 6 |
| Package Type | 8-SOIJ (Small Outline IC, J-leaded) |
| Operating Temperature Range | -40 C to +85 C (Industrial) |
| Mounting Type | Surface Mount |
| Oscillator Type | Internal RC / External |
| ADC | None (digital I/O only) |
| Watchdog Timer | Yes |
| RoHS Status | Compliant |
PIC12C508-04I/SM Pin Configuration
| Pin 1 | GP5/OSC1/CLKIN — I/O pin GP5 / oscillator input / external clock input |
| Pin 2 | GP4/OSC2/CLKOUT — I/O pin GP4 / oscillator output / clock output |
| Pin 3 | GP3/MCLR/VPP — I/O pin GP3 / Master Clear reset / programming voltage |
| Pin 4 | GP2/T0CKI — I/O pin GP2 / Timer0 clock input |
| Pin 5 | GP1 — I/O pin GP1 |
| Pin 6 | GP0 — I/O pin GP0 |
| Pin 7 | VSS — Ground reference |
| Pin 8 | VDD — Positive supply voltage |
Typical Applications
PIC12C508-04I/SM is suitable for 6 applications: Low-Cost Consumer Appliance Controller, Automotive Body Electronics, LED Lighting Controller, Battery-Powered Sensor Interface, Hobbyist and Educational Projects, Simple Industrial Timer and Counter.
Low-Cost Consumer Appliance Controller
The PIC12C508-04I/SM fits appliance controllers because its 6 I/O pins drive LEDs, relays, and keypads directly while the 4 MHz core handles timing, debounce, and sequencing without external components. With 768 bytes of OTP, firmware can encode mode logic, sensor thresholds, and fault handling for products such as fans, toasters, and coffee makers. Compared to a discrete logic implementation, the device replaces 3-5 ICs and reduces PCB area significantly.
Recommended
Automotive Body Electronics
The PIC12C508-04I/SM is well suited for non-safety automotive body electronics such as interior lighting, window timers, and keyless-entry receivers because its industrial temperature range (-40C to +85C) handles cabin and engine-bay conditions. The 2.5V-5.5V supply tolerates automotive battery transients and direct 12V rail operation with a small linear regulator. Its 33-instruction RISC core simplifies ASIL-QM firmware and keeps development cycles short.
Recommended
LED Lighting Controller
The PIC12C508-04I/SM drives LED strips, chase patterns, and dimmers using PWM on its 6 I/O pins, with each pin able to source or sink enough current for a logic-level MOSFET gate. The 4 MHz core executes breath, blink, and color-mixing algorithms in real time, while the wide 2.5V-5.5V supply works directly from single-cell Li-ion or 5V USB. OTP memory locks the final lighting profile at production.
Recommended
Battery-Powered Sensor Interface
The PIC12C508-04I/SM is ideal for low-duty-cycle sensor nodes because its fully static design allows the CPU to be stopped between samples, dropping current consumption to microamp levels. Six I/O pins support I2C, SPI, or simple GPIO sensor connections, while 768 bytes of OTP accommodates calibration tables and digital filtering. The 2.5V minimum supply works directly from two alkaline or one Li-ion cell.
Recommended
Hobbyist and Educational Projects
The PIC12C508-04I/SM is widely used in microcontroller training kits and hobbyist projects because its 33-instruction RISC architecture is straightforward to learn and the 6 I/O pins are sufficient for breadboard experimentation with LEDs, buttons, and serial communication. Developers can simulate and debug firmware using MPLAB X IDE and the PICkit programmer ecosystem. Despite OTP, development kits use the JW windowed package for iteration.
Recommended
Simple Industrial Timer and Counter
The PIC12C508-04I/SM replaces mechanical timers and discrete counters in industrial cabinets, providing precise millisecond timing with the 4 MHz instruction cycle and configurable watchdog. Six I/O pins drive relays, optocouplers, and status LEDs directly. Its industrial -40C to +85C rating tolerates factory-floor temperatures, and OTP memory prevents firmware tampering.
Recommended
Recommended Products Summary
Engineering reference data for PIC12C508-04I/SM — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC12C508A-04I/SM | PIC12C508-04/SM | PIC12C508A-04/SM | PIC12C508T-04I/SM | PIC12C508T-04E/SM |
|---|---|---|---|---|---|---|
| Package | 8-SOIJ | 8-SOIJ - same | 8-SOIJ - same | 8-SOIJ - same | 8-SOIJ - same | 8-SOIJ - same |
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Program Memory | 768 B OTP | 768 B OTP | 768 B OTP | 768 B OTP | 768 B OTP | 768 B OTP |
| CPU Speed | 4 MHz | 4 MHz | 4 MHz | 4 MHz | 4 MHz | 4 MHz |
| Operating Temperature | -40C to +85C (Industrial) | -40C to +85C (Industrial) | 0C to +70C (Commercial) | 0C to +70C (Commercial) | -40C to +85C (Industrial) | -40C to +125C (Extended) |
| Comparator | No | Yes (1 comparator) | No | Yes (1 comparator) | No | No |
| I/O Pins | 6 | 6 | 6 | 6 | 6 | 6 |
| Operating Voltage | 2.5V to 5.5V | 2.5V to 5.5V | 2.5V to 5.5V | 2.5V to 5.5V | 2.5V to 5.5V | 2.5V to 5.5V |
Key Differentiators
- Wide 2.5V to 5.5V operating voltage supports both 3.3V and 5V rails (vs PIC12C508-04/SM)
- Industrial temperature grading included (vs PIC12C508-04/SM)
- Originally specified PIC12C508 core, the canonical 8-pin OTP design (vs PIC12C508A-04I/SM)
Design Notes
Place a 100 nF ceramic decoupling capacitor within 5 mm of the VDD pin (pin 8), and add a 10 uF bulk capacitor on the same supply rail. According to the Microchip datasheet 40139E, the device draws 1.8 mA typical at 4 MHz and 5V, but in sleep mode drops to under 1 uA. For battery applications, leverage sleep aggressively - the static core allows the clock to halt entirely while registers retain state.
Do not drive GP3 (MCLR/VPP, pin 3) with an external device while it is configured as a reset input - the device requires a 50 kohm pull-up to VDD. According to the Microchip datasheet 40139E, configuring GP3 as a digital input requires the MCLRE configuration bit to be cleared in the configuration word, after which pin 3 becomes general-purpose I/O. OTP programming is irreversible - verify firmware thoroughly before production runs.
Route the oscillator traces (GP4/OSC2 and GP5/OSC1, pins 1-2) short and surrounded by ground to minimize EMI pickup. According to the Microchip datasheet 40139E, when using an external crystal, both load capacitors must be placed within 5 mm of the respective oscillator pins. Keep high-current switching traces (relays, LEDs) away from the oscillator loop to avoid clock jitter.
Compliance Information
RoHS and lead-free compliant per Microchip product page. Not AEC-Q100 qualified; for automotive safety applications, use AEC-Q100-qualified PIC alternatives. Halogen-free status not explicitly stated in retrieved web data.
