PIC12C508-04/P - 8-Bit 4MHz OTP MCU 768B | Microchip
MPN: PIC12C508-04/P ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $2.7 | $2.70 |
| 10 | $2.43 | $24.30 |
| 100 | $2.16 | $216.00 |
| 500 | $1.85 | $925.00 |
| 1,000 | $1.62 | $1,620.00 |
PIC12C508-04/P Overview
A microcontroller (MCU) is a single-chip computer that integrates a CPU, RAM, non-volatile program memory, and programmable I/O peripherals. The PIC12C508 belongs to the baseline PIC12 family, the simplest tier within Microchip's 8-bit PIC architecture hierarchy: PIC10/12/16/18 baseline and mid-range families -> 8-bit PIC microcontrollers -> microcontroller ICs -> embedded processors -> semiconductors. Baseline PICs use a 12-bit instruction word and a 33-instruction RISC core, which makes them exceptionally easy to program yet powerful enough for simple control loops.
Key features include 6 bidirectional I/O pins (GP0-GP5), a watchdog timer with on-chip RC oscillator, power-on reset, power-saving SLEEP mode, and code protection. The 12C508 lacks an analog comparator and A/D converter, distinguishing it from the PIC12C508A revision; it is intended for pure digital glue-logic replacement and simple state-machine duties. The OTP program memory is one-time programmable, which makes this part attractive for low-cost volume production where firmware is finalized.
The device uses a Harvard RISC architecture with separate program and data buses, allowing instruction fetch and operand access in the same cycle. Each instruction is a fixed 12-bit word, and 33 single-word single-cycle instructions cover arithmetic, logical, branch, and bit-manipulation operations. The four oscillator modes (LP, XT, HS, RC) let designers trade off cost, frequency, and power across a wide range of applications.
Typical applications include battery chargers, timer/counter modules, security systems, low-cost consumer appliances, and any cost-sensitive board that previously used discrete 555/4017 logic. Designers also deploy it in industrial controllers and remote sensor interfaces that benefit from its tiny 8-pin footprint.
When designing with this device, allocate one I/O pin as a firmware-programming entry on production boards to enable in-system firmware update via Microchip's ICSP protocol. Remember that OTP memory cannot be erased, so a single programming error on a production batch consumes the part.
This page synthesizes distributor pricing, drop-in PIC10/PIC12 alternatives, and practical design notes not consolidated in the manufacturer datasheet.
Drop-in alternatives for PIC12C508-04/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 PIC12C508-04/P (same form factor and footprint) — differing in Package, Operating Temperature, Timers, Program Memory Size, Mounting Type.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PIC12C508A-04/P
✅ Drop-In✓ In Stock
$0.95 / Unit
View Datasheet →PIC12F508-I/P
✅ Drop-In📋 Reference alternative (not in catalog)
PIC12C508-04E/P
✅ Drop-In📋 Reference alternative (not in catalog)
PIC12C508-04/SM
✅ Drop-In📋 Reference alternative (not in catalog)
PIC10F200-I/P
✅ Drop-In✓ In Stock
$0.28 / Unit
View Datasheet →PIC10F202-I/P
✅ Drop-In✓ In Stock
$0.47 / Unit
View Datasheet →PIC10F220-I/P
✅ Drop-In✓ In Stock
$0.49 / Unit
View Datasheet →PIC12C508-04/P Maximum Ratings & Electrical Characteristics
| Core | PIC 8-bit RISC |
| Architecture | Harvard, 12-bit instruction word |
| Program Memory Type | OTP (One-Time Programmable) EPROM |
| Program Memory Size | 768 B (512 x 12 words) |
| RAM | 25 B |
| Maximum CPU Frequency | 4 MHz |
| Instruction Execution Time | 200 ns (single-cycle at 4 MHz) |
| Operating Voltage Range | 2.5 V to 5.5 V (typical 3.3 V / 5 V) |
| Number of I/O Pins | 6 (GP0-GP5) |
| Package | 8-pin PDIP (0.300 inch / 7.62 mm) |
| Mounting Type | Through-Hole |
| Operating Temperature Range | -40 C to +85 C |
| Oscillator Modes | LP, XT, HS, RC (internal RC available) |
| Peripherals | Watchdog Timer, Power-On Reset, SLEEP mode |
| Instruction Set Size | 33 single-word single-cycle instructions |
| A/D Converter | None |
| Comparator | None |
| Code Protection | Supported |
| MSL Level | 1 (unlimited floor life) |
| RoHS Status | Compliant |
PIC12C508-04/P Pin Configuration
| Pin 1 | GP5/OSC1/CLKIN — GPIO GP5 / oscillator input / external clock input |
| Pin 2 | GP4/OSC2/CLKOUT — GPIO GP4 / oscillator output / clock output |
| Pin 3 | GP3/MCLR/VPP — GPIO GP3 / Master Clear reset / programming voltage input |
| Pin 4 | GP2/T0CKI — GPIO GP2 / Timer0 clock input |
| Pin 5 | GP1 — GPIO GP1 |
| Pin 6 | GP0 — GPIO GP0 |
| Pin 7 | VSS — Ground reference |
| Pin 8 | VDD — Positive supply voltage (2.5 V to 5.5 V) |
Typical Applications
PIC12C508-04/P is suitable for 6 applications: Battery Charger Control, Timer / Counter Module Replacement, Security System Keypad Decoder, Consumer Appliance Controller, Remote Sensor Interface Node, Industrial Control Replacement.
Battery Charger Control
The PIC12C508-04/P's 4 MHz RISC core and 768 B of OTP memory provide sufficient headroom to implement CC/CV charge profiles for small Li-ion and NiMH packs. Its 25 B RAM handles real-time voltage/current sampling via the comparator-less GPIO path using an external TL431 reference, and SLEEP mode keeps quiescent current below 15 uA between sampling intervals. The 6 GPIO pins drive status LEDs, charge-enable FETs, and a thermistor input mux without external glue logic. Designers value the OTP architecture for cost-down charger production where firmware is finalized; the 8-pin PDIP remains easy to hand-solder on small charger boards.
Recommended
Timer / Counter Module Replacement
Many legacy 555-timer and 4017-counter designs can be consolidated onto a single PIC12C508-04/P, replacing dozens of discrete components. The 200 ns instruction execution at 4 MHz supports precise timing down to 1 us resolution using the TMR0 counter with T0CKI on GP4, while watchdog timer provides autonomous recovery. Six GPIO pins expose multiple timing channels (delay-on-make, delay-on-break, interval-on, interval-off) configured entirely in firmware, eliminating hardware trim pots. OTP memory locks the timing parameters against field tampering, important for industrial timer products.
Recommended
Security System Keypad Decoder
Security keypads benefit from the PIC12C508-04/P's code-protection feature, which prevents firmware reverse-engineering of the access code algorithm. The 33-instruction RISC core can scan a 3x4 matrix keypad using only 4 GPIO pins (3 rows + 1 column strobe, time-multiplexed) and drive a relay output on GP0. OTP program memory makes code extraction destructive if the protection fuse is set, deterring cloning of the security algorithm. The 8-pin PDIP footprint is small enough to fit inside a standard keypad housing alongside the matrix switches.
Recommended
Consumer Appliance Controller
Cost-sensitive consumer appliances (coffee makers, blenders, hair dryers, air purifiers) commonly use the PIC12C508-04/P for motor speed, heater duty-cycle, and user-interface control. The 2.5 V to 5.5 V supply range tolerates rectified mains step-down rails directly, and the 4 MHz core can PWM a TRIAC or opto-isolated SSR via TMR0 interrupts. SLEEP mode drops current below 15 uA for standby efficiency regulations. The OTP-programmed firmware cannot be field-modified, which manufacturers use as an anti-tamper feature on appliances.
Recommended
Remote Sensor Interface Node
Battery-powered remote sensor nodes (temperature loggers, leak detectors, occupancy sensors) leverage the PIC12C508-04/P's 15 uA SLEEP current and 4 MHz active mode to maximize battery life. A thermistor or switch input on GP0/GP1 is polled periodically, with the watchdog timer waking the device from SLEEP every few seconds. The 768 B OTP memory stores calibration coefficients and node ID, while the 25 B RAM buffers the latest reading. Six GPIO pins drive a low-power RF transmitter enable line and an LED indicator.
Recommended
Industrial Control Replacement
Industrial controllers migrating from 74HC-series discrete logic often consolidate state machines onto the PIC12C508-04/P, reducing PCB area and BOM count. The 8-pin PDIP fits standard 0.300 inch DIP sockets, easing replacement in legacy equipment. Watchdog timer and power-on reset provide robust recovery from brownout events on noisy industrial 24 V rails stepped down to 5 V, while the -40 C to +85 C industrial temperature range handles factory-floor environments. OTP memory locks the control logic against unauthorized modification.
Recommended
Recommended Products Summary
Engineering reference data for PIC12C508-04/P — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC12C508A-04/P | PIC12F508-I/P | PIC12C508-04E/P | PIC10F200-I/P |
|---|---|---|---|---|---|
| Package | 8-pin PDIP (0.300 inch) | 8-pin PDIP (0.300 inch) - same | 8-pin PDIP (0.300 inch) - same | 8-pin PDIP (0.300 inch) - same | 8-pin PDIP (0.300 inch) - same |
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Program Memory Type | OTP EPROM | OTP EPROM | Flash | OTP EPROM | Flash |
| Program Memory Size | 768 B (512 x 12) | 768 B (512 x 12) | 768 B (512 x 12) | 768 B (512 x 12) | 384 B (256 x 12) |
| Maximum Frequency | 4 MHz | 4 MHz | 4 MHz (8 MHz option -I) | 4 MHz | 4 MHz |
| RAM | 25 B | 25 B | 25 B | 25 B | 16 B |
| I/O Pins | 6 | 6 | 6 | 6 | 4 |
| Analog Comparator | No | Yes | Yes | No | No |
| Operating Temperature | -40 C to +85 C | -40 C to +85 C | -40 C to +85 C | -40 C to +125 C (extended) | -40 C to +85 C |
Key Differentiators
- Lowest-cost OTP baseline PIC in 8-pin PDIP (vs PIC12F508-I/P)
- Extended temperature option with identical die (vs PIC12C508-04E/P)
- Adds on-chip comparator at no pin cost (vs PIC12C508A-04/P)
- Flash reprogrammability for development (vs PIC10F200-I/P)
Design Notes
OTP memory cannot be erased - any programming error permanently consumes the part. Microchip recommends prototyping with the flash-based PIC12F508-I/P (pin-compatible) and only moving to PIC12C508-04/P for cost-down production once firmware is finalized. Also note that GP3 doubles as MCLR/VPP; disabling MCLR via the configuration fuse frees GP3 as a general-purpose I/O, but then external reset must be implemented via software watchdog.
At 5 V and 4 MHz the PIC12C508-04/P draws approximately 2 mA active and less than 15 uA in SLEEP mode. For battery-powered designs, configure the watchdog timer to wake from SLEEP every 2-4 seconds and complete all I/O operations within 5 ms before re-entering SLEEP. This duty-cycle approach typically achieves 5-10 year battery life on a single CR2032 coin cell.
Place a 100 nF decoupling capacitor as close as possible to the VDD pin (pin 8) and a 10 uF bulk capacitor near the MCU on the same PCB. The MCLR/VPP pin (pin 3) requires a 10 kohm pull-up to VDD for normal operation; if in-circuit serial programming (ICSP) is required, route the ICSPCLK/ICSPDAT lines to a 5-pin header. Keep the OSC1/OSC2 traces short to minimize EMI pickup on the oscillator node.
For designs using an external crystal (XT or HS mode), keep the crystal traces within 5 mm of the OSC1/OSC2 pins and surround them with a ground pour to isolate from switching nodes. In RC oscillator mode, place the timing resistor and capacitor close to the OSC1 pin to avoid parasitic capacitance that would shift frequency. For EMI-sensitive consumer products, configure the configuration fuse to use the internal 4 MHz RC oscillator and disable CLKOUT on GP4.
Compliance Information
RoHS and REACH compliant per Microchip product page. Not AEC-Q100 qualified; for automotive designs use PIC12F508-E or PIC16F equivalents that are AEC-Q100 listed.
