PIC12C508AT-04E/SM - 8-bit 4MHz OTP MCU, 768B, 6 I/O | Microchip
MPN: PIC12C508AT-04E/SM ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $0.71 | $0.71 |
| 10 | $0.64 | $6.40 |
| 100 | $0.55 | $55.00 |
| 500 | $0.48 | $240.00 |
| 1,000 | $0.42 | $420.00 |
| 3,000 | $0.36 | $1,080.00 |
PIC12C508AT-04E/SM Overview
An 8-bit microcontroller (MCU) is a single-chip processor that integrates a CPU core, program memory, data RAM, and I/O peripherals in a small form factor. The PIC12C508AT belongs to Microchip's PIC12C family, which sits inside the broader 8-bit PIC microcontroller hierarchy (8-bit MCU → microcontroller → embedded controller → semiconductor). These MCUs are widely used in cost-sensitive, space-constrained, and deterministic-control designs where low power and a minimal instruction set are more valuable than raw throughput.
Key features include 33 single-word instructions, an 8-bit real-time clock/counter (TMR0) with an 8-bit programmable prescaler, power-on reset (POR), device reset timer (DRT), watchdog timer (WDT) with its own on-chip RC oscillator, programmable code protection, and an operating voltage range of 2.5 V to 5.5 V (extended). The part supports six general-purpose I/O pins and offers 1,000,000 erase/write cycles per the device family rating.
Architecturally, the PIC12C508AT uses Harvard-style separate program and data paths with a 12-bit instruction word, enabling 200 ns instruction execution at 4 MHz. The OTP program memory (EPROM) is written during production or in-system once, supporting small-to-medium volume embedded products. The on-chip watchdog timer with its dedicated internal RC oscillator guarantees reliable operation even if the main system clock is disrupted, which is essential in industrial and automotive environments.
Typical applications include low-cost consumer appliances, sensor signal conditioning, LED lighting controllers, automotive body electronics (subsystems), small motor control, and remote-control transmitters. The wide 2.5 V-5.5 V supply range and extended operating temperature range allow the part to drop into battery-powered and harsh-environment designs.
When designing with this device, allocate sufficient time for OTP programming during pilot builds because OTP memory cannot be reprogrammed in-circuit. Always enable the watchdog timer in firmware and consider the EPROM device lifecycle (typically 1,000,000 erase/write cycles) when planning field updates.
This page synthesizes distributor pricing, drop-in alternatives, and practical design notes not found in the manufacturer datasheet, giving engineers an at-a-glance comparison for sourcing and second-source planning.
Drop-in alternatives for PIC12C508AT-04E/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 PIC12C508AT-04E/SM (same form factor and footprint) — differing in Core Architecture, Instruction Execution Time, Package, Program Memory Size, Timers.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PIC12C508A-04E/SM
✅ Drop-In📋 Reference alternative (not in catalog)
PIC12C508A-04/SM
✅ Drop-In📋 Reference alternative (not in catalog)
PIC12C508-04/SM
✅ Drop-In📋 Reference alternative (not in catalog)
PIC12C508A-04I/SM
✅ Drop-In✓ In Stock
$1.05 / Unit
View Datasheet →PIC12C509A-04E/SM
✅ Drop-In✓ In Stock
$1.55 / Unit
View Datasheet →PIC12C508AT-04/SN
✅ Drop-In📋 Reference alternative (not in catalog)
PIC12C508AT-04E/SM Maximum Ratings & Electrical Characteristics
| Product Type | 8-bit Microcontroller (MCU) |
| Core Architecture | PIC (RISC), 12-bit instruction word |
| Family | PIC® 12C |
| Maximum Clock Speed | 4 MHz |
| Instruction Execution Time | 1 µs (200 ns at 4 MHz, family rating) |
| Program Memory Size | 768 B (512 × 12) OTP |
| RAM Size | 25 B |
| I/O Pins | 6 |
| Timers | TMR0 (8-bit) with 8-bit programmable prescaler |
| Watchdog Timer | Yes, with dedicated on-chip RC oscillator |
| Power-On Reset (POR) | Yes |
| Device Reset Timer (DRT) | Yes |
| Code Protection | Programmable |
| Supply Voltage Range | 2.5 V to 5.5 V (Extended) |
| Operating Temperature Range | -40 °C to +125 °C (Extended, "E") |
| Package | 8-pin SOIJ (SM) - tape and reel |
| Mounting Type | Surface Mount |
| RoHS Status | Compliant (per Microchip product page) |
PIC12C508AT-04E/SM Pin Configuration
| Pin 1 | GP5/OSC1/CLKIN — Bidirectional I/O pin / oscillator crystal input / external clock input |
| Pin 2 | GP4/OSC2/CLKOUT — Bidirectional I/O pin / oscillator crystal output / clock output |
| Pin 3 | GP3/MCLR/VPP — Bidirectional I/O pin / Master Clear reset (active low) / programming voltage input |
| Pin 4 | VSS — Ground reference |
| Pin 5 | GP0 — Bidirectional I/O pin |
| Pin 6 | GP1 — Bidirectional I/O pin |
| Pin 7 | GP2/T0CKI — Bidirectional I/O pin / Timer0 clock input |
| Pin 8 | VDD — Positive supply voltage |
Typical Applications
PIC12C508AT-04E/SM is suitable for 7 applications: Low-Cost Consumer Appliance Control, Sensor Signal Conditioning Front-End, LED Lighting Controller, Automotive Body Electronics Subsystems, Remote Control Transmitter, Small Motor Control (Brushed DC), Industrial Sensor Interface Module.
Low-Cost Consumer Appliance Control
The PIC12C508AT-04E/SM fits low-cost consumer appliance control because its 768 B OTP program memory and 25 B RAM are sufficient for small fixed-function firmware (button debouncing, relay timing, LED blinking). The 4 MHz clock and 1 µs instruction cycle handle basic state-machine control loops, while the extended -40 °C to +125 °C range supports kitchen and laundry environments. Six I/O pins map cleanly to typical user interfaces: 3-4 inputs for buttons/sensors plus 2-3 outputs for triac/relay/LED drivers. The OTP architecture saves BOM cost in high-volume SKUs.
Recommended
Sensor Signal Conditioning Front-End
The PIC12C508AT-04E/SM works well as a sensor signal conditioning front-end in cost-driven designs. Its 6 I/O pins can read multiple analog channels (via on-chip comparators on PIC12C508 family) or digital sensors, and the 8-bit TMR0 with prescaler handles timing-critical sampling without external counters. The 2.5 V-5.5 V supply range accepts both 3.3 V sensor rails and 5 V legacy analog front-ends. Low cost (under $0.50 at qty 1k) makes it economical to place one PIC per sensor node in distributed sensing architectures.
Recommended
LED Lighting Controller
The PIC12C508AT-04E/SM is ideal for low-end LED lighting controllers (single-channel dimmers, decorative strips, status indicators) where the 6 I/O pins drive multiple MOSFET gates or LED current sinks. The PIC12C architecture supports PWM via firmware loops on the TMR0 prescaler, allowing dimming without dedicated PWM peripherals. The wide 2.5 V-5.5 V input range handles 3.3 V logic-level MOSFETs and 5 V analog dimmer interfaces alike. The 4 MHz clock is ample for 100 Hz PWM refresh with 8-bit resolution.
Recommended
Automotive Body Electronics Subsystems
The PIC12C508AT-04E/SM operates across -40 °C to +125 °C with 2.5 V-5.5 V supply, suiting non-safety automotive body subsystems such as interior lighting, mirror controllers, wiper timers, and seat-position memories. The on-chip watchdog timer with its dedicated RC oscillator improves reliability under automotive electrical transients. Six I/O pins can read switches (door, seat, ignition) and drive small relays or LEDs. For AEC-Q100-qualified alternatives, choose PIC12F675 automotive variants.
Recommended
Remote Control Transmitter
The PIC12C508AT-04E/SM is well-suited for battery-powered remote control transmitters because the PIC12C architecture is inherently low-power and 768 B of OTP is plenty for fixed infrared/RF encoding tables. Six I/O pins can scan 2-3 buttons and drive an IR LED or 433 MHz SAW transmitter. The 2.5 V minimum supply works from two alkaline or NiMH cells. The OTP architecture eliminates reprogramming risk in the field and minimizes BOM cost for high-volume consumer remotes.
Recommended
Small Motor Control (Brushed DC)
The PIC12C508AT-04E/SM handles small brushed-DC motors (fans, vibrators, toys) by using two I/O pins as direction-control outputs to an H-bridge driver, plus one or two pins for Hall-effect or back-EMF sensing. The 4 MHz clock with TMR0 prescaler produces software PWM at up to ~20 kHz with 8-bit duty resolution, adequate for sub-100 mA brushed motors. The extended temperature range supports enclosed motor housings, and the low unit cost ($0.36 at qty 3k) keeps the BOM economical for consumer motor products.
Recommended
Industrial Sensor Interface Module
The PIC12C508AT-04E/SM is a cost-effective controller for industrial sensor interface modules (proximity detectors, limit switches, photoelectric sensors). The on-chip watchdog timer with independent RC oscillator ensures recovery from brown-outs and ESD events common in industrial plants. The 2.5 V-5.5 V supply works from 24 V industrial rails stepped down to 5 V or 3.3 V. Six I/O pins accommodate two sensor inputs plus two relay/MODBUS-driver outputs and a status LED. The extended -40 °C to +125 °C operating range handles factory floor conditions.
Recommended
Recommended Products Summary
Engineering reference data for PIC12C508AT-04E/SM — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC12C508A-04E/SM | PIC12C508A-04/SM | PIC12C508-04/SM | PIC12C508A-04I/SM | PIC12C509A-04E/SM | PIC12C508AT-04/SN |
|---|---|---|---|---|---|---|---|
| Brand | Microchip Technology | Microchip Technology - same | Microchip Technology - same | Microchip Technology - same | Microchip Technology - same | Microchip Technology - same | Microchip Technology - same |
| Package | 8-SOIJ (SM) | 8-SOIJ (SM) - same | 8-SOIJ (SM) - same | 8-SOIJ (SM) - same | 8-SOIJ (SM) - same | 8-SOIJ (SM) - same | 8-SOIC (SN) - same pin count, similar footprint |
| Program Memory | 768 B (512 × 12) OTP | 768 B OTP - same | 768 B OTP - same | 768 B OTP - same | 768 B OTP - same | 1.5 KB OTP - upgrade | 768 B OTP - same |
| RAM Size | 25 B | 25 B - same | 25 B - same | 25 B - same | 25 B - same | 41 B - upgrade | 25 B - same |
| Maximum Clock Speed | 4 MHz | 4 MHz - same | 4 MHz - same | 4 MHz - same | 4 MHz - same | 4 MHz - same | 4 MHz - same |
| Operating Temperature Range | -40 °C to +125 °C (Extended) | -40 °C to +125 °C - same | 0 °C to +70 °C - commercial | 0 °C to +70 °C - commercial | -40 °C to +85 °C - industrial | -40 °C to +125 °C - same | -40 °C to +125 °C - same |
| Supply Voltage Range | 2.5 V to 5.5 V | 2.5 V to 5.5 V - same | 2.5 V to 5.5 V - same | 2.5 V to 5.5 V - same | 2.5 V to 5.5 V - same | 2.5 V to 5.5 V - same | 2.5 V to 5.5 V - same |
| I/O Pins | 6 | 6 - same | 6 - same | 6 - same | 6 - same | 6 - same | 6 - same |
| OTP (One-Time Programmable) | Yes | Yes - same | Yes - same | Yes - same | Yes - same | Yes - same | Yes - same |
| Approximate Unit Price (qty 1) | $0.71 | Similar to this part | Similar to this part | Similar to this part | Similar to this part | Slightly higher (~+10%) | Similar to this part |
Key Differentiators
- Tape-and-reel packaging suffix ("T") in the ordering code (vs PIC12C508A-04E/SM)
- Extended -40 °C to +125 °C temperature grade (suffix "E") (vs PIC12C508A-04/SM)
- Same 8-SOIJ footprint as the broader PIC12C508A family (vs PIC12C509A-04E/SM)
- Lower unit cost than the PIC12C509A for code-light designs (vs PIC12C509A-04E/SM)
Design Notes
The PIC12C508AT-04E/SM is OTP (one-time programmable). Unlike flash-based MCUs, OTP memory cannot be erased and reprogrammed in-circuit, so any firmware change after programming requires a new part. Pilot builds must be carefully validated before committing to volume OTP programming because the cost of an in-field firmware bug is a full board respin. For prototypes, use a windowed ceramic package PIC12C508A or a flash-based PIC10F200/PIC12F675 for development, then move to PIC12C508AT-04E/SM for production.
Decouple VDD with a 100 nF ceramic capacitor placed within 3 mm of the VDD pin, with a low-impedance ground return to the VSS pin. The PIC12C5XX datasheet recommends a 10 µF bulk capacitor for noisy supply environments. The brown-out detection circuit requires a clean VDD ramp; if the supply has slow rise time (>50 ms), hold MCLR low until VDD stabilizes to avoid spurious resets. For battery-powered designs, leverage the PIC12C sleep mode (with WDT enabled) to drop current below 1 µA.
When using an external crystal or resonator, keep traces short (<5 mm) and route them over a continuous ground plane. Place the crystal/resonator within 5 mm of OSC1 and OSC2 (pins 1 and 2) and shield it from high-current switching traces. The GP3/MCLR/VPP pin (pin 3) is sensitive to noise; place a 10 kΩ pull-up to VDD and a 100 nF capacitor to VSS near the pin to filter ESD events. For SOIJ packages, ensure the PCB land pattern matches JEDEC SOIC-8 dimensions with 1.27 mm pin pitch.
GP3 is input-only on the PIC12C508A family - it cannot be used as a digital output, even though it appears on the bidirectional I/O list. According to the PIC12C5XX datasheet, GP3 shares the MCLR/VPP function and is multiplexed exclusively to those roles except as a digital input. Plan your I/O assignments accordingly: use GP0, GP1, GP2, GP4, GP5 as the five true bidirectional I/O, leaving GP3 as an input or reset line.
Compliance Information
RoHS compliance per Microchip product page. Not AEC-Q100 qualified - the PIC12C508A family is targeted at consumer, industrial, and non-safety automotive subsystems. For AEC-Q100-qualified automotive designs, use a PIC12F or PIC16F variant explicitly listed on the Microchip automotive website.
