PIC12C508A-04I/P - 8-bit 4MHz OTP MCU 768B | Microchip
MPN: PIC12C508A-04I/P ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $1.4 | $1.40 |
| 10 | $1.22 | $12.20 |
| 100 | $1.05 | $105.00 |
| 500 | $0.92 | $460.00 |
| 1,000 | $0.81 | $810.00 |
PIC12C508A-04I/P Overview
What is a PIC12C5XX microcontroller? The PIC12C5XX family from Microchip Technology represents a class of low-cost, high-performance 8-bit fully-static CMOS microcontrollers built on a RISC architecture with only 33 single-word single-cycle instructions. Within the taxonomy, PIC microcontrollers belong to the broader category of microcontrollers (MCUs) -> embedded controllers -> semiconductor ICs. This minimalist instruction set, combined with a Harvard memory architecture, gives the PIC12C508A deterministic interrupt latency and predictable timing - qualities valued in automotive, appliance, and consumer products where code simplicity is paramount.
Key features of the PIC12C508A-04I/P include an internal 4 MHz RC oscillator (with the -04 speed designation), an on-chip power-on reset, a watchdog timer with its own on-chip RC oscillator for reliable operation without external components, and code protection to prevent unauthorized memory reads. The 8-pin PDIP form factor is the most user-friendly package for prototyping and low-volume production, accepting standard DIP sockets and breadboards.
Technically, the device uses a 12-bit instruction word that is byte-addressable through a 7+2 special function register + 25 general purpose register file. Power consumption is rated in the microamp range during sleep mode with the watchdog timer active, and the device supports in-circuit serial programming (ICSP) for production-line firmware loading even after the OTP window has been sealed.
Typical applications include automotive sensor interfaces, appliance controls (washing machines, microwaves), security keypads, simple sensor conditioning, battery chargers, and low-cost consumer products. The industrial temperature range (-40C to +85C) is indicated by the 'I' suffix in the part number.
Designers should note that OTP memory can only be programmed once - development should use the PIC12C508A-04/P (extended temperature, no 'I' suffix denotes commercial 0C to +70C) or a Flash-based pin-compatible PIC10F200/202/220/222 for prototyping. The 6 I/O pins share functions with the comparator, timer, and ICSP interfaces, so careful pin allocation is required.
This page synthesizes distributor inventory, same-brand drop-in alternatives, and practical design notes that are not aggregated in a single manufacturer datasheet, giving engineers a faster path to sourcing and validation.
Drop-in alternatives for PIC12C508A-04I/P — 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-04I/P (same form factor and footprint) — differing in Package, Program Memory Type, Program Memory Size, Timers, 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-04E/P
✅ Drop-In✓ In Stock
$1.74 / Unit
View Datasheet →PIC12C508-04I/SM
✅ Drop-In✓ In Stock
$1.18 / Unit
View Datasheet →PIC12C508-04/P
✅ Drop-In✓ In Stock
$1.62 / Unit
View Datasheet →PIC12F508-I/P
✅ Drop-In✓ In Stock
$0.5 / Unit
View Datasheet →PIC10F200-I/P
✅ Drop-In✓ In Stock
$0.28 / Unit
View Datasheet →PIC10F202-I/P
✅ Drop-In✓ In Stock
$0.47 / Unit
View Datasheet →PIC12C508A-04I/P Maximum Ratings & Electrical Characteristics
| Core Architecture | Enhanced PIC16C5X, 8-bit RISC |
| Instruction Set Size | 33 single-word instructions |
| Program Memory Type | OTP EPROM (One-Time Programmable) |
| Program Memory Size | 768 bytes (512 x 12 words) |
| RAM Size | 25 bytes |
| I/O Pins | 6 general-purpose |
| Maximum CPU Frequency | 4 MHz |
| Instruction Cycle Time | 1 microsecond at 4 MHz |
| Operating Voltage Range | 2.5 V to 5.5 V |
| Operating Temperature Range | -40 C to +85 C (Industrial, 'I' suffix) |
| Package | 8-pin PDIP (Plastic DIP) |
| Mounting Type | Through-Hole |
| Timers | 1 x 8-bit Timer0 with prescaler |
| Watchdog Timer | Yes, with dedicated on-chip RC oscillator |
| Power-On Reset | Yes, on-chip |
| Internal Oscillator | Yes, 4 MHz RC (-04 speed designation) |
| Brown-Out Reset | Not present on PIC12C508A |
| In-Circuit Serial Programming (ICSP) | Yes |
| Code Protection | Yes, via configuration bit |
| RoHS Status | Compliant |
| MSL Level | 1 (unlimited floor life at <30 C / 85% RH) |
PIC12C508A-04I/P Pin Configuration
| Pin 1 | GP5/OSC1/CLKIN — GPIO port bit 5 / oscillator input / external clock input |
| Pin 2 | GP4/OSC2 — GPIO port bit 4 / oscillator output |
| Pin 3 | GP3/MCLR/VPP — GPIO port bit 3 / master clear reset input / ICSP programming voltage |
| Pin 4 | GP2/T0CKI — GPIO port bit 2 / Timer0 clock input |
| Pin 5 | GP1 — GPIO port bit 1 |
| Pin 6 | GP0 — GPIO port bit 0 |
| Pin 7 | VSS — Ground reference |
| Pin 8 | VDD — Positive supply voltage (2.5 V to 5.5 V) |
Typical Applications
PIC12C508A-04I/P is suitable for 6 applications: Automotive Sensor Interface, White Goods Appliance Control, Security Keypad and Access Control, Battery Charger Controller, Simple Sensor Conditioning Node, Consumer Toy and Hobby Electronics.
Automotive Sensor Interface
The PIC12C508A-04I/P fits automotive sensor interface modules because its industrial -40C to +85C temperature range covers under-hood and cabin environments, and the 6 GPIO pins can directly drive a sensor MUX, comparator reference, and LIN-style UART bit-bang. The internal 4 MHz RC oscillator eliminates the external crystal, reducing BOM cost and PCB area in space-constrained engine bay modules. With OTP memory, the firmware is locked at production, providing tamper resistance valued by Tier-1 automotive suppliers. The 768-byte program memory accommodates small sensor-conditioning routines (linearization, threshold detection, PWM output) at sub-microamp sleep currents suitable for always-on battery-monitored nodes.
Recommended
White Goods Appliance Control
In washing machines, dishwashers, and microwave ovens, the PIC12C508A-04I/P runs the user-interface state machine, keypad scan, and triac-fire timing for the motor or heater load. The 4 MHz internal RC and integrated watchdog timer provide sufficient timing accuracy for line-frequency zero-crossing detection while remaining immune to brown-out glitches during motor inrush. Six GPIOs are enough for a 4-key keypad plus two relay/triac outputs, and the 1 microsecond instruction cycle supports 50/60 Hz zero-crossing handling with margin. OTP memory locks the firmware against field tampering, a benefit for warranty and regulatory compliance in household appliances.
Recommended
Security Keypad and Access Control
Security keypads and RFID access controllers benefit from the PIC12C508A-04I/P because code protection locks the OTP memory against extraction, preventing cloning of credential algorithms. The internal 4 MHz oscillator drives a debounced keypad scan and a low-speed UART or Wiegand output to the host controller, with the watchdog timer catching code-flow anomalies. Industrial temperature rating lets the same part serve both indoor and outdoor keypad enclosures. 768 bytes of program memory fits the keypad matrix logic plus a small credential validation routine, and the 6 GPIOs handle a 3x4 matrix plus status LED.
Recommended
Battery Charger Controller
The PIC12C508A-04I/P acts as a low-cost slave controller in nickel-metal-hydride or lithium-ion charger modules, where it monitors V/I thresholds through the comparator and toggles a charge FET. The 2.5 V minimum VDD lets it run directly from a single Li-ion cell without a boost regulator, and sub-microamp sleep current preserves battery life between charge sessions. The 6 GPIOs can drive the charge FET, status LED, and a temperature sense input. OTP memory is appropriate here because the charge profile is fixed and locked at production, eliminating the need for field firmware updates.
Recommended
Simple Sensor Conditioning Node
Wireless sensor nodes for HVAC, agriculture, and industrial monitoring often use the PIC12C508A-04I/P as the local signal-conditioning MCU between an analog sensor and a low-power radio. The device reads a thermistor or resistive bridge, linearizes the output, and pushes a Manchester-encoded bitstream to the transmitter. The internal 4 MHz oscillator delivers consistent timing for bit-banged protocols, while the watchdog timer prevents lockup in unattended deployments. With the industrial temperature rating, the same part serves outdoor agricultural deployments and indoor HVAC ducts without component changes.
Recommended
Consumer Toy and Hobby Electronics
The PIC12C508A-04I/P is widely used in low-cost consumer toys, electronic novelties, and hobby kits because the 8-pin PDIP package is breadboard-friendly and the OTP memory keeps unit cost at the absolute minimum. Six GPIOs drive LEDs, small DC motors via MOSFETs, and piezo buzzers for sound effects. The 4 MHz internal oscillator is sufficient for simple PWM motor control and LED dimming without external components. Hobbyists appreciate that the same part is supported by free Microchip MPLAB X IDE toolchains and a vast library of example code accumulated over decades.
Recommended
Recommended Products Summary
Engineering reference data for PIC12C508A-04I/P — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC12C508A-04/P | PIC12C508A-04E/P | PIC12F508-I/P | PIC10F200-I/P | PIC10F202-I/P |
|---|---|---|---|---|---|---|
| Package | 8-pin PDIP (through-hole) | 8-pin PDIP - same | 8-pin PDIP - same | 8-pin PDIP - same | 8-pin PDIP - same | 8-pin PDIP - same |
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Program Memory Type | OTP EPROM (768 bytes) | OTP EPROM (768 bytes) | OTP EPROM (768 bytes) | Flash (768 bytes) | Flash (256 bytes) | Flash (512 bytes) |
| Program Memory Size | 768 bytes (512 x 12 words) | 768 bytes | 768 bytes | 768 bytes | 256 bytes (-50%) | 512 bytes (same) |
| RAM Size | 25 bytes | 25 bytes | 25 bytes | 25 bytes | 16 bytes (-36%) | 24 bytes (close) |
| Maximum CPU Frequency | 4 MHz | 4 MHz | 4 MHz | 4 MHz | 4 MHz | 4 MHz |
| Operating Voltage Range | 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 | 2.0 V to 5.5 V | 2.0 V to 5.5 V |
| Operating Temperature Range | -40 C to +85 C (industrial) | 0 C to +70 C (commercial) | -40 C to +125 C (extended) | -40 C to +85 C (industrial) | -40 C to +85 C (industrial) | -40 C to +85 C (industrial) |
| GPIO Count | 6 | 6 | 6 | 6 | 4 (-2) | 4 (-2) |
Key Differentiators
- Lowest unit cost in volume among 8-pin PIC MCUs (vs PIC12F508-I/P)
- Industrial temperature range included by default (vs PIC12C508A-04/P)
- Larger program memory than PIC10F family equivalents (vs PIC10F200-I/P)
Design Notes
GP3/MCLR/VPP is shared between reset, digital input, and ICSP programming voltage. Per the Microchip PIC12C5XX datasheet, pin 3 must not be left floating - tie to VDD through a 10 kohm resistor if it is unused as GPIO, otherwise the master-clear reset may trigger spuriously. In ICSP designs, the VPP high-voltage pulse on pin 3 can disturb external circuits sharing this pin, so isolate with a small series resistor or buffer transistor. Always verify the MCLR enable configuration bit matches your reset architecture (internal vs external).
Place a 100 nF decoupling capacitor as close as possible to the VDD pin (pin 8) with the ground return directly to VSS (pin 7). The internal 4 MHz RC oscillator of the -04 speed variant is sensitive to VDD noise; for applications requiring tight timing accuracy across temperature, use the lower-speed internal oscillator mode or an external crystal on pins 1-2. Keep high-current traces (relay, triac) routed away from the oscillator pins to avoid injected noise. A ground pour on the bottom layer under the MCU improves both thermal dissipation and noise immunity.
The PIC12C508A-04I/P draws microamp-range current in sleep mode with the watchdog timer enabled, making it suitable for battery-powered sensor nodes. Per the Microchip PIC12C5XX datasheet, wake-up from sleep is triggered by watchdog timeout, external interrupt on GP3, or pin change on GP0/GP1/GP3. To minimize sleep current, disable unused peripherals via the configuration word and set all unused GPIO pins to outputs driving low. Avoid using the internal 4 MHz oscillator in high-temperature designs above 85 C without checking the frequency drift specification.
Compliance Information
RoHS and REACH compliance confirmed per Microchip product page. Not AEC-Q100 qualified; for automotive AEC-Q100 designs use PIC16F or dsPIC variants instead. Halogen-free status not specified in available web data.
