PIC12F508-E/SN - 8-Bit 4MHz Flash MCU, 768B, 6 I/O | Microchip
MPN: PIC12F508-E/SN ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $0.95 | $0.95 |
| 10 | $0.86 | $8.60 |
| 100 | $0.76 | $76.00 |
| 500 | $0.68 | $340.00 |
| 1,000 | $0.62 | $620.00 |
PIC12F508-E/SN Overview
What is an 8-bit Flash microcontroller? An 8-bit Flash microcontroller is a single-chip computer built around an 8-bit data path, with program memory implemented in non-volatile Flash (rather than ROM, EPROM, or one-time programmable memory). This category sits inside the broader microcontroller hierarchy (microcontroller -> embedded processor -> semiconductor) and is widely used in cost- and pin-sensitive designs where 32-bit performance is not required.
Key features of the PIC12F508-E/SN include a RISC instruction set with only 33 single-word instructions, an internal 4MHz RC oscillator (no external crystal needed), an 8-bit timer with prescaler, a watchdog timer, and in-circuit serial programming (ICSP) via two pins. With only 8 pins total, 6 of which are available as I/O, the part is designed for ultra-compact PCB designs such as single-chip sensor interfaces, small appliances, and simple logic-replacement modules.
The PIC12F508-E/SN uses a Harvard-architecture core with separate program and data buses, a 2-stage pipeline, and 12-bit-wide instructions. According to the manufacturer datasheet, this delivers typical 2:1 code compression over competing 8-bit MCUs in the same price class. The device consumes very low operating current and supports power-saving modes, making it suitable for battery-powered applications.
Typical applications include LED blinkers and lighting controllers, battery chargers, sensor signal conditioning, simple motor control (small fans, solenoids), remote-control transmitter logic replacement, and automotive courtesy / interior lamps. The wide 2.0V-5.5V supply range supports both 3.3V and 5V rails commonly found in legacy industrial systems.
When designing with this part, allocate two pins to ICSP (VDD/GND-style dual-purpose programming pins) to preserve in-circuit debug capability. Choose an external reset strategy carefully - the device offers optional internal weak pull-ups but no full brown-out reset on all variants.
This page synthesizes distributor pricing, drop-in alternatives from Microchip's PIC12F family, and practical design notes not found in the manufacturer datasheet.
Drop-in alternatives for PIC12F508-E/SN — 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 PIC12F508-E/SN (same form factor and footprint) — differing in Package, MSL Level, Maximum CPU Speed, Core Architecture, Data EEPROM.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PIC12F508-I/SN
✅ Drop-In✓ In Stock
$0.31 / Unit
View Datasheet →PIC12F509-E/SN
✅ Drop-In✓ In Stock
$0.55 / Unit
View Datasheet →PIC12F509-I/SN
✅ Drop-In✓ In Stock
$0.71 / Unit
View Datasheet →PIC12F1501-E/SN
✅ Drop-In✓ In Stock
$0.58 / Unit
View Datasheet →PIC12F1571-E/SN
✅ Drop-In✓ In Stock
$0.65 / Unit
View Datasheet →PIC12F1822-E/SN
✅ Drop-In📋 Reference alternative (not in catalog)
PIC12F508-E/SN Maximum Ratings & Electrical Characteristics
| Core | PIC 8-bit RISC |
| Architecture | Harvard, 2-stage pipeline |
| Program Memory | 768 bytes (512 x 12) Flash |
| RAM | 25 bytes |
| Data EEPROM | None |
| Number of I/O | 6 |
| Maximum CPU Speed | 4 MHz |
| Instruction Set | 33 instructions, 12-bit wide |
| Supply Voltage | 2.0 V to 5.5 V |
| Operating Temperature | -40 C to +125 C (Extended) |
| Package | 8-SOIC (SN) 0.154 inch / 3.90 mm width |
| Mounting Type | Surface Mount |
| Timers | 1 x 8-bit with prescaler |
| Watchdog Timer | Yes |
| Internal Oscillator | 4 MHz RC (factory calibrated) |
| Programming Interface | ICSP (In-Circuit Serial Programming) |
| ADC | None |
| RoHS Status | Compliant |
PIC12F508-E/SN Pin Configuration
| Pin 1 | VDD — Positive power supply input |
| Pin 2 | GP5/T1OSI/CLKIN — Bidirectional I/O pin / Timer1 oscillator input / external clock input |
| Pin 3 | GP4/T1G/OSC2/CLKOUT — Bidirectional I/O pin / Timer1 gate / oscillator output / clock output |
| Pin 4 | GP3/MCLR/VPP — Bidirectional I/O pin / Master Clear reset (active low) / programming voltage input |
| Pin 5 | GP2/INT/OSC1 — Bidirectional I/O pin / external interrupt / oscillator input |
| Pin 6 | GP1/ICSPDAT — Bidirectional I/O pin / ICSP data |
| Pin 7 | GP0/ICSPCLK — Bidirectional I/O pin / ICSP clock |
| Pin 8 | VSS — Ground reference |
Typical Applications
PIC12F508-E/SN is suitable for 6 applications: LED Blinker and Lighting Controllers, Battery-Powered Sensor Interfaces, Remote-Control and Logic-Replacement Modules, Small Appliance and Fan Control, Automotive Courtesy and Interior Lamps, Simple Logic-Replacement Timers and Blinker Modules.
LED Blinker and Lighting Controllers
The PIC12F508-E/SN fits LED blinker and lighting-controller designs because its 4 MHz internal RC oscillator and single 8-bit timer with prescaler are sufficient to generate accurate blink rates from sub-Hz to kHz. The 6 I/O pins can drive MOSFET gates directly via internal weak pull-ups, and the 768-byte Flash holds a complete PWM or chase-pattern routine. The wide 2.0 V to 5.5 V supply means a single design runs from a 3 V coin cell or a 5 V USB rail without modification, and the extended -40 C to +125 C temperature range supports outdoor signage. Recommended companions include low-side MOSFETs and TVS diodes on the LED string.
Recommended
Battery-Powered Sensor Interfaces
The PIC12F508-E/SN fits battery-powered sensor interface designs because the 2.0 V minimum supply allows operation down to the cutoff of two alkaline cells, and the Sleep instruction plus Watchdog Timer enable microamp-level standby current. With 6 I/O available, the part can read a digital sensor over a single-wire or I/O pin, perform threshold-based decisions in firmware, and wake only on a pin-change interrupt. The 768-byte Flash holds a state-machine or simple protocol handler. The internal RC oscillator eliminates external crystal quiescent current, extending battery life.
Recommended
Remote-Control and Logic-Replacement Modules
The PIC12F508-E/SN fits logic-replacement modules and simple remote-control transmitter designs where cost and pin count dominate. The 12-bit-wide 33-instruction RISC core executes a tight loop in microseconds, ideal for generating IR carrier frequencies, RC servo pulses, or 1-wire protocols. The 6 I/O can directly drive an IR LED with a transistor, and the part tolerates 5 V supply from any common 3 x AA or USB rail. According to the Microchip datasheet, this device is one of the lowest-cost 8-bit Flash MCUs available, making it the canonical replacement for legacy discrete-logic timing circuits.
Recommended
Small Appliance and Fan Control
The PIC12F508-E/SN fits small appliance and low-power fan control designs. The single 8-bit timer with prescaler can generate PWM via firmware, and the 6 I/O pins can drive a TRIAC gate, read a zero-cross detect, and accept a tactile button input. The 768-byte Flash holds a soft-start, ramp-down, and fault-state machine, and the extended -40 C to +125 C temperature grade supports under-hood automotive and appliance environments. Recommended companion parts include a zero-cross optocoupler and a TRIAC for the load-switching stage.
Recommended
Automotive Courtesy and Interior Lamps
The PIC12F508-E/SN fits automotive courtesy and interior-lamp fade modules because of its extended -40 C to +125 C temperature grade and 2.0 V to 5.5 V supply range, which covers 12 V battery systems after regulation. With only 6 I/O pins the part can read a door-switch input, drive a single MOSFET for a courtesy lamp, and generate a soft fade-in/fade-out timing curve in firmware. According to Microchip, the part is specified for automotive-grade process capability, making it a strong fit for under-dash and interior-lighting applications.
Recommended
Simple Logic-Replacement Timers and Blinker Modules
The PIC12F508-E/SN fits discrete-logic replacement applications where a 555 timer or a 74HC logic chain would normally be used. The internal 4 MHz oscillator plus the 8-bit timer produce accurate delays from microseconds to seconds, and 6 I/O pins can replace several discrete logic gates. The 768-byte Flash holds a complete state machine for applications such as turn-signal flashers, HVAC blinker indicators, and simple sequential controllers. This is the canonical use case for the PIC12F family and demonstrates the lowest total BoM cost in volume production.
Recommended
Recommended Products Summary
Engineering reference data for PIC12F508-E/SN — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC12F508-I/SN | PIC12F509-E/SN | PIC12F1501-E/SN | PIC12F1571-E/SN | PIC12F1822-E/SN |
|---|---|---|---|---|---|---|
| Package | 8-SOIC (SN) | 8-SOIC (SN) - same | 8-SOIC (SN) - same | 8-SOIC (SN) - same | 8-SOIC (SN) - same | 8-SOIC (SN) - same |
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Program Flash | 768 bytes (512 x 12) | 768 bytes | 1.5 KB (1024 x 12) | 1.75 KB | 1.75 KB | 3.5 KB |
| RAM | 25 bytes | 25 bytes | 41 bytes | 64 bytes | 64 bytes | 128 bytes |
| Maximum CPU Speed | 4 MHz | 4 MHz | 4 MHz | 16 MHz | 16 MHz | 32 MHz |
| Operating Temperature | -40 C to +125 C (E grade) | -40 C to +85 C (I grade) | -40 C to +125 C (E grade) | -40 C to +125 C (E grade) | -40 C to +125 C (E grade) | -40 C to +125 C (E grade) |
| Supply Voltage | 2.0 V to 5.5 V | 2.0 V to 5.5 V | 2.0 V to 5.5 V | 1.8 V to 5.5 V | 1.8 V to 5.5 V | 1.8 V to 5.5 V |
| Number of I/O | 6 | 6 | 6 | 6 | 6 | 6 |
| Timers | 1 x 8-bit with prescaler | 1 x 8-bit | 1 x 8-bit | 3 x 8/16-bit + PWM | 3 x 8/16-bit + PWM | 4 x 8/16-bit + PWM |
| ADC / PWM / Interrupt | None / None / None | None / None / None | None / None / None | 10-bit ADC / 4-ch PWM / Yes | 10-bit ADC / 4-ch PWM / Yes | 10-bit ADC / 4-ch PWM / Yes |
Key Differentiators
- Lowest-cost 8-bit Flash MCU in SOIC-8 from Microchip (vs PIC12F1822-E/SN)
- Pin-compatible superset upgrade path to PIC12F509 (vs PIC12F509-E/SN)
- Extended temperature grade to +125 C for automotive/industrial (vs PIC12F508-I/SN)
- Internal factory-calibrated 4 MHz oscillator, no external crystal (vs PIC12F1571-E/SN)
Design Notes
Place a 100 nF decoupling capacitor as close as possible to the VDD pin (pin 1), with a return path directly to VSS (pin 8). The PIC12F508-E/SN has 6 I/O pins, and switching outputs can inject noise into VDD; a small ceramic decoupling cap prevents brown-out. For battery-powered designs, the internal 4 MHz RC oscillator eliminates crystal current, but a 10 uF bulk capacitor near VDD helps during transmit bursts. Ensure that VDD rise time stays below the brown-out reset window if you use the PIC's internal WDT-driven power-on reset.
Route the ICSP lines (GP0/ICSPCLK and GP1/ICSPDAT) so that a 5-pin header can be placed at the board edge for in-circuit programming. Both pins are shared with GP0/GP1 digital I/O, so avoid putting large capacitors on them that would slow the ICSP signal edges. Leave at least 5 mm of clearance around the ICSP header for the programming clip. According to the manufacturer datasheet, no special isolation is required, but the GP3/MCLR line should have a 10 kohm pull-up to VDD to prevent unintended resets in noisy environments.
Watch for these common pitfalls: (1) GP3 is MCLR/VPP and is bidirectional; if you need an extra I/O pin, enabling the internal MCLR via CONFIG removes GP3 from the digital-I/O pool. (2) The 33-instruction baseline core has no hardware interrupt controller; pin-change and timer flags must be polled in firmware unless you use an upgrade part. (3) Writing to Flash from application code is not supported on the PIC12F508; if you need in-application reprogramming, choose PIC12F509 or PIC12F1501. (4) No data EEPROM exists - store NV parameters in a reserved Flash word with proper block-erase handling.
The PIC12F508-E/SN dissipates negligible power due to its CMOS design - typical operating current is well under 1 mA active and a few microamps in Sleep mode. The 8-SOIC package has a theta_JA of approximately 100 C/W in still air, but at this power level the rise above ambient is only a few degrees. No thermal management is required for any reasonable ambient. According to the datasheet, the absolute maximum junction temperature is +150 C, which is never approached in normal operation. The extended -40 C to +125 C temperature grade covers virtually all indoor, automotive, and outdoor use cases.
The PIC12F508-E/SN has no hardware interrupt controller, so signal-edge detection relies on firmware polling or the pin-change-on-GP0/GP1/GP3 feature (where implemented). For noisy input signals, add a small RC filter (10 kohm + 100 nF, tau = 1 ms) on the input pin to debounce mechanically-driven sources. The internal Schmitt-trigger input thresholds (typically 0.45 x VDD / 0.15 x VDD) provide good noise margin for clean 3.3 V and 5 V logic. If you must generate precise timing, calibrate the internal 4 MHz RC oscillator via the OSCCAL register, which the manufacturer pre-trims at factory calibration.
Compliance Information
RoHS compliant per Microchip product page. AEC-Q100 qualified variants are not available in the PIC12F508 family; PIC12F1822 and PIC16F15313 are the recommended automotive-grade alternatives in the 8-pin class.
