PIC12C508A/JW - 8-bit EPROM MCU, 4MHz, 768B, UV | Microchip
MPN: PIC12C508A/JW ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $12.5 | $12.50 |
| 10 | $11.25 | $112.50 |
| 100 | $9.8 | $980.00 |
| 500 | $8.75 | $4,375.00 |
| 1,000 | $7.95 | $7,950.00 |
PIC12C508A/JW Overview
A microcontroller (MCU) is a single-chip computer that integrates a CPU, program memory, data memory, and programmable I/O peripherals. The PIC12C508A belongs to the 8-bit microcontrollers -> PIC microcontrollers -> PIC12C family product hierarchy. It targets cost-sensitive embedded applications where a minimal 8-pin footprint and predictable deterministic execution are required. The /JW windowed package is specifically intended for erasing the EPROM via UV light during code development and prototyping, not for production deployment.
Key features include 768 bytes of EPROM program memory (512 x 12), 25 bytes of RAM, 6 programmable I/O lines, an internal 4 MHz RC oscillator, an internal power-on reset, a watchdog timer, and power-saving SLEEP mode. The device operates from 2.5V to 5.5V across commercial 0C to +70C (this JW variant) and consumes less than 2 mA at 5V, 4 MHz. It is pin-compatible with the PIC12C508, PIC12CE518, and PIC12F508/509 Flash families, simplifying code migration during product transitions.
The PIC12C508A uses a Harvard RISC architecture with separate program and data buses, a 12-bit wide instruction word delivering 2:1 code compression over typical 8-bit CISC controllers, and a hardware stack only two levels deep. The reduced instruction set and deterministic timing simplify real-time control firmware and embedded interrupt handling. The integrated MCLR/GP3 pin serves dual functions as master clear and general-purpose I/O with interrupt capability.
Typical applications include low-cost appliance controllers, sensor signal conditioning, intelligent sensor front-ends, simple PWM LED drivers, automotive body modules (industrial grade variants), and educational/development kits where the EPROM window allows iterative code erase/reprogram cycles. Designers evaluating firmware before committing to OTP PIC12C508A-04/P or flash PIC12F508-I/P production parts use the JW package in the design phase.
When designing with this MCU, ensure the GP3/MCLR pin is properly biased because it serves as both master clear and I/O. The device lacks an on-chip UART or ADC, so designers requiring analog or serial communication must add external components or migrate to the PIC12F675/683 Flash family with integrated peripherals. The JW ceramic windowed package is significantly more expensive than the plastic PDIP production version and should not be used in final production.
This page synthesizes distributor pricing, drop-in package-compatible alternatives (PIC12C508A-04/P, PIC12F508-I/P), and practical design guidance not found in the manufacturer datasheet alone.
Drop-in alternatives for PIC12C508A/JW — 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 PIC12C508A/JW (same form factor and footprint) — differing in Program Memory Type, Package, Program Memory Size, Instruction Set, Watchdog Timer.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PIC12C508A-04/P
✅ Drop-In✓ In Stock
$0.95 / Unit
View Datasheet →PIC12C508A-04I/P
✅ Drop-In✓ In Stock
$0.81 / Unit
View Datasheet →PIC12C508A-04E/P
✅ Drop-In✓ In Stock
$1.74 / Unit
View Datasheet →PIC12C508-04/P
✅ Drop-In ⚠️ 参数待验证✓ In Stock
$1.62 / Unit
View Datasheet →PIC12F508-I/P
✅ Drop-In✓ In Stock
$0.5 / Unit
View Datasheet →PIC12C508A/JW Maximum Ratings & Electrical Characteristics
| Architecture | 8-bit RISC (Enhanced PIC16C5X core) |
| Instruction Set | 33 single-word, single-cycle instructions |
| Instruction Execution Time | 1 us (at 4 MHz) |
| Program Memory Type | EPROM (UV-erasable, JW windowed package) |
| Program Memory Size | 768 B (512 x 12 words) |
| Data RAM | 25 bytes |
| EEPROM Data Memory | None |
| Operating Frequency | 4 MHz (max) |
| Supply Voltage Range | 2.5 V to 5.5 V |
| I/O Pins | 6 (GP0-GP5) |
| Internal Oscillator | 4 MHz RC (selectable) |
| Watchdog Timer | Yes (independent RC, software-enabled) |
| Power-on Reset | Yes (internal) |
| Brown-out Reset | No |
| SLEEP Mode | Yes |
| Hardware Stack | 2 levels |
| Package | 8-pin CDIP (JW, windowed ceramic) |
| Mounting Type | Through-Hole |
| Pin Count | 8 |
| Operating Temperature Range | 0C to +70C (commercial, JW variant) |
| RoHS Status | Non-compliant (windowed ceramic package) |
| Pb-free / Lead-free | No (contains lead in ceramic package) |
PIC12C508A/JW Pin Configuration
| Pin 1 | GP2 — Bidirectional I/O pin (T1CKI alternate function) |
| Pin 2 | GP3/MCLR/Vpp — Bidirectional I/O / Master Clear reset / Programming voltage |
| Pin 3 | GP4/OSC2 — Bidirectional I/O / Oscillator output |
| Pin 4 | GP5/OSC1/CLKIN — Bidirectional I/O / Oscillator input / External clock input |
| Pin 5 | Vss — Ground reference |
| Pin 6 | GP0 — Bidirectional I/O pin |
| Pin 7 | GP1/T0CKI — Bidirectional I/O / Timer0 clock input |
| Pin 8 | Vdd — Positive supply voltage (2.5 V to 5.5 V) |
Typical Applications
PIC12C508A/JW is suitable for 6 applications: Appliance Control Firmware Development, Intelligent Sensor Front-End, Simple PWM LED Driver, Educational Microcontroller Trainer, Automotive Body Module Prototype, Industrial Sensor Signal Conditioning.
Appliance Control Firmware Development
The PIC12C508A/JW suits development of small appliance control firmware where iterative code erase/reprogram cycles are essential. The 4 MHz RISC core delivers 1 us instruction execution with deterministic timing, ideal for motor speed control and timer-based sequence management. The UV-erasable EPROM and JW windowed package allow engineers to repeatedly test code versions on the same physical MCU before locking firmware into the production PIC12C508A-04/P OTP part. Pin count is minimal: 6 I/O drive relays, LEDs, and keypad inputs directly. Recommended companion: PIC12C508A-04/P (production OTP), PIC16F1823 (migrated modern core).
Recommended
Intelligent Sensor Front-End
Low-cost sensor conditioning applications benefit from the PIC12C508A/JW small 8-pin footprint and low 2 mA active current at 5V. The MCU reads analog sensors via simple RC timing on the T0CKI pin (GP1) or external comparator and outputs a digital control signal. With only 25 bytes RAM, firmware is restricted to simple lookup tables and threshold decisions rather than heavy processing. The 768-byte EPROM is adequate for direct sensor-to-actuator mapping logic. Recommended companion: PIC12F675 (with 10-bit ADC), MCP9700 (analog temp sensor).
Recommended
Simple PWM LED Driver
The PIC12C508A/JW delivers software PWM on its 6 I/O pins, sufficient for dimming single-color LEDs or driving RGB color-mixing via three software PWM channels. At 4 MHz, PWM resolution is approximately 8 bits with 244 Hz refresh, well above the flicker-fusion threshold. Low component count (only the MCU plus current-limit resistors) reduces BOM cost. Internal oscillator eliminates external RC components. The 2.5 V to 5.5 V supply range supports single-cell Li-ion and USB-powered lighting applications. Recommended companion: PIC12F615 (hardware PWM), PCA9633 (LED driver).
Recommended
Educational Microcontroller Trainer
Educational labs favor the PIC12C508A/JW for teaching embedded programming fundamentals because the JW windowed package allows students to erase and reprogram the same device many times, reducing per-lab cost. The 33-instruction RISC instruction set is small enough to learn in a single session and large enough to demonstrate real assembly-level control. All PIC architecture fundamentals (program counter, stack, I/O registers, interrupts) are present. Migration to PIC12F508-I/P for senior projects adds in-circuit reprogramming. Recommended companion: PICkit 1 programmer, MPLAB X IDE.
Recommended
Automotive Body Module Prototype
Industrial and automotive body-electronics prototypes leverage the PIC12C508A/JW during firmware development for door-lock, seat-position, and lighting controls where small 8-pin packaging fits tight in-line connector modules. The extended temperature PIC12C508A-04I/P variant supports underhood environments. The EPROM / JW windowed package lets engineers iterate against HALT and EMC qualification cycles. Watchdog timer ensures software lockup recovery in noisy vehicle environments. Recommended companion: PIC12F508-I/P (production), TLE4276 (5V automotive LDO).
Recommended
Industrial Sensor Signal Conditioning
Industrial sensor signal conditioning boards use the PIC12C508A/JW for digital trim of analog sensor outputs via GP0/GP1 controlling digital potentiometers or DACs. The hardware watchdog timer prevents field lockup in unattended installations. The 2.5 V to 5.5 V supply range supports both 3.3 V and 5 V industrial sensor rails. The deterministic 1 us instruction cycle is reliable for closed-loop control. Migration to PIC12F508-I/P adds Flash for last-minute firmware tweaks in the field. Recommended companion: MCP4011 (digital potentiometer), MCP4725 (DAC).
Recommended
Recommended Products Summary
Engineering reference data for PIC12C508A/JW — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC12C508A-04/P | PIC12C508A-04I/P | PIC12F508-I/P |
|---|---|---|---|---|
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Package | 8-pin CDIP (JW windowed ceramic) | PDIP-8 (same pinout) | PDIP-8 (same pinout) | PDIP-8 (same pinout) |
| Program Memory Type | 768 B EPROM (UV-erasable) | 768 B EPROM (OTP) | 768 B EPROM (OTP) | 768 B Flash (re-programmable) |
| Program Memory Size | 768 B (512 x 12) | 768 B (512 x 12) | 768 B (512 x 12) | 768 B (512 x 12) |
| Data RAM | 25 B | 25 B | 25 B | 25 B |
| Max Clock Frequency | 4 MHz | 4 MHz | 4 MHz | 4 MHz (20 MHz for PIC12F508) |
| Supply Voltage | 2.5 V to 5.5 V | 2.5 V to 5.5 V | 2.5 V to 5.5 V | 2.0 V to 5.5 V |
| Operating Temperature | 0C to +70C (Commercial, JW) | 0C to +70C (Commercial) | -40C to +85C (Industrial) | -40C to +85C (Industrial) |
| I/O Pins | 6 | 6 | 6 | 6 |
| Approximate Unit Price (qty 1) | $12.50 (as of 2026-09-14) | $1.80 | $2.10 | $1.60 |
Key Differentiators
- UV-erasable EPROM allows repeated code iteration on the same physical device (vs PIC12C508A-04/P (OTP))
- Flash in-circuit reprogramming with same pinout (vs PIC12F508-I/P (Flash))
- Industrial temperature range for harsh environments (vs PIC12C508A-04I/P)
- Extended temperature -40C to +125C for underhood automotive (vs PIC12C508A-04E/P)
Design Notes
The PIC12C508A/JW windowed ceramic package is significantly more expensive than the production OTP plastic counterpart (PIC12C508A-04/P), and the EPROM erase cycle requires 20-30 minutes of UV exposure. Do not deploy JW devices in production builds - they are intended exclusively for firmware development and pre-production validation. Use the plastic PDIP-8 production part for all customer-facing units.
Estimated power budget: at 5 V Vdd and 4 MHz active mode, the PIC12C508A draws approximately 2 mA; in SLEEP mode this drops to less than 1 uA with watchdog disabled, enabling battery-powered sensor applications. A 10 uF tantalum plus 0.1 uF ceramic decoupling pair placed within 5 mm of the Vdd pin is essential for noise immunity on the GP3/MCLR line, which is sensitive to Vdd droop. Brown-out reset is NOT integrated - external voltage supervisor (e.g., MCP100) is required for automotive and industrial deployments.
The PIC12C508A 8-pin PDIP footprint is industry-standard and accepts both the JW windowed ceramic and the OTP plastic PIC12C508A-04/P variants, allowing the same PCB to host development and production parts. Keep the GP3/MCLR/Vpp trace short (<25 mm) and route away from switching signals to avoid spurious resets. The quartz window on JW packages is fragile; protect it with a sticker during handling and never allow direct finger contact with the window, which can leave oils that block UV erasure.
The PIC12C508A internal RC oscillator is rated at 4 MHz nominal with +/- 10% tolerance across temperature, sufficient for UART bit-banged timing only at low baud rates (<2400). For reliable serial communication or precision timing, switch to the external GP5/OSC1 + GP4/OSC2 crystal/ceramic resonator mode. The T0CKI pin (GP1) supports external Timer0 clocking with 50 ns minimum pulse width; debounce mechanical switches via a 10 nF cap + 10 kohm pull-up if direct GPIO input is required.
Compliance Information
JW windowed ceramic package contains lead (Pb) and is NOT RoHS compliant; production OTP plastic variants PIC12C508A-04/P and Flash PIC12F508-I/P are RoHS compliant. REACH compliance per Microchip product declaration. AEC-Q100 qualification not available for this part - automotive designs should migrate to AEC-Q100 qualified PIC16F1xx family or use industrial-temperature variants with external qualification testing.
