PIC12C671T-04I/SM - 8-Bit OTP MCU, 4MHz, 1.75KB | Microchip
MPN: PIC12C671T-04I/SM β Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $2.45 | $2.45 |
| 10 | $2.18 | $21.80 |
| 100 | $1.84 | $184.00 |
| 500 | $1.55 | $775.00 |
| 1,000 | $1.32 | $1,320.00 |
PIC12C671T-04I/SM Overview
What is a PIC 8-bit microcontroller? A microcontroller (MCU) is a single-chip computer that integrates a CPU, non-volatile program memory (ROM/OTP/Flash), volatile data memory (RAM), and a configurable set of peripheral interfaces such as I/O ports, timers, and analog-to-digital converters (ADCs). The PIC12C67x family belongs to Microchip's mid-range 8-bit RISC architecture, which is widely used in consumer appliances, automotive subsystems, industrial sensors, and battery-powered instruments. Within the broader semiconductor taxonomy, it sits as: PIC12C671 -> PIC12C family -> PIC10/12/16 mid-range -> 8-bit MCU -> microcontroller -> integrated circuit.
Key features include 35 single-word instructions (200 ns instruction cycle at 4 MHz), 8-bit ADC with 4 input channels, four oscillator options (RC, LP, XT, HS), an 8-bit real-time clock/counter with 8-bit prescaler, and a watchdog timer for reliable unattended operation. The OTP program memory supports in-circuit programming via Microchip's ICSP interface, while the brown-out detect and power-on reset blocks provide robust supply-voltage supervision. Maximum power dissipation is specified at 700 mW.
The architecture combines a Harvard-bus CPU with a 14-bit instruction word and separate 8-bit data path, which is characteristic of the mid-range PIC families. The integrated ADC uses successive-approximation register (SAR) conversion with 8-bit resolution, suitable for low-bandwidth sensor sampling such as thermistor bridges, potentiometers, and battery monitors. The device supports in-system debugging through Microchip's ICD and the MPLAB PM3 programmer, which work with the entire PIC12C6xx line.
Typical applications include appliance control boards, sensor signal conditioning, simple closed-loop fan or pump controllers, automotive interior accessories, battery chargers, security keypads, and low-cost consumer products. The 6 I/O pins are sufficient for driving small relays, LED indicators, and UART-style bit-banged communication.
A key design consideration is OTP vs Flash: because the PIC12C671 uses one-time-programmable memory, firmware must be fully validated before programming - the part cannot be reprogrammed in the field. Designs targeting field upgrades should consider the PIC12F/F67x Flash-based siblings. The SOIJ (SM) package is a small-outline IC with J-leads, suitable for both hand-soldered prototypes and high-volume SMT lines.
This page synthesizes distributor pricing, drop-in pin-compatible alternatives, and practical design notes - information not consolidated in the manufacturer datasheet alone.
Drop-in alternatives for PIC12C671T-04I/SM β 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 PIC12C671T-04I/SM (same form factor and footprint) β differing in Program Memory Size, Core Architecture, I/O Pins, Package, Program Memory Type.
Quick Comparison Tool β Select alternative parts for side-by-side comparison:
PIC12C671-04I/SM
β Drop-Inπ Reference alternative (not in catalog)
PIC12C671T-04E/SM
β Drop-Inβ In Stock
$2.38 / Unit
View Datasheet βPIC12C671T-04/SM
β Drop-Inπ Reference alternative (not in catalog)
PIC12C672T-04I/SM
β Drop-In β οΈ εζ°εΎ ιͺθ―π Reference alternative (not in catalog)
PIC12CE674T-04I/SM
β Drop-In β οΈ εζ°εΎ ιͺθ―π Reference alternative (not in catalog)
PIC12C509A-04I/SM
β Drop-In β οΈ εζ°εΎ ιͺθ―β In Stock
$0.93 / Unit
View Datasheet βPIC12C671T-04I/SM Maximum Ratings & Electrical Characteristics
| Core Architecture | 8-bit PIC RISC (mid-range) |
| Program Memory Type | OTP (One-Time Programmable) |
| Program Memory Size | 1.75 KB (1K x 14 words) |
| RAM Size | 128 bytes |
| Data EEPROM | Not present (12C671 has no EEPROM; see 12CE67x) |
| Maximum Clock Speed | 4 MHz |
| Instruction Cycle | 200 ns at 4 MHz |
| Supply Voltage (VDD) | 3.0 V to 5.5 V |
| I/O Pins | 6 (bidirectional, programmable) |
| ADC | 8-bit, 4 input channels |
| Timers | 1 x 8-bit timer/counter with 8-bit prescaler |
| Watchdog Timer | Yes (with dedicated on-chip RC oscillator) |
| Brown-out Reset | Yes |
| Power-on Reset | Yes |
| In-Circuit Programming | Yes (ICSP, 2-wire) |
| Oscillator Modes | RC, LP, XT, HS (external); internal RC option |
| Operating Temperature | -40C to +85C (industrial, I grade) |
| Maximum Power Dissipation | 700 mW |
| Package | 8-pin SOIJ (SM) |
| Mounting Type | Surface Mount |
| RoHS Status | Compliant |
| Lead-Free | Yes |
PIC12C671T-04I/SM Pin Configuration
| Pin 1 | GP5/OSC1/CLKIN β General-purpose I/O / oscillator input / external clock input |
| Pin 2 | GP4/OSC2/CLKOUT β General-purpose I/O / oscillator output / clock output |
| Pin 3 | GP3/MCLR/VPP β General-purpose I/O / Master Clear reset (active low) / programming voltage |
| Pin 4 | GP2/AN2/T0CKI β General-purpose I/O / analog input 2 / Timer0 clock input |
| Pin 5 | GP1/AN1/CIN-/ICSPCLK β General-purpose I/O / analog input 1 / comparator in- / ICSP clock |
| Pin 6 | GP0/AN0/CIN+/ICSPDAT β General-purpose I/O / analog input 0 / comparator in+ / ICSP data |
| Pin 7 | VDD β Positive supply voltage (3.0 V to 5.5 V) |
| Pin 8 | VSS β Ground reference |
Typical Applications
PIC12C671T-04I/SM is suitable for 6 applications: Appliance Control Boards, Battery-Powered Sensor Nodes, Automotive Interior Accessories, Security Keypads and Access Control, Simple Closed-Loop Fan/Pump Controllers, LED Lighting Drivers and Indicators.
Appliance Control Boards
The PIC12C671T-04I/SM fits appliance control boards because its 6 programmable I/O pins drive relay coils, triac interfaces, status LEDs, and key-scan matrices common in washing machines, microwave ovens, and rice cookers. The integrated 8-bit ADC samples NTC thermistors for over-temperature shutdown, while brown-out reset and watchdog timer provide the fault recovery required by IEC 60730 household appliance safety standards. At $1.32 in 1k quantities, the part keeps BOM cost low enough for high-volume white goods. Its 4 MHz clock and 1.75 KB OTP suffice for state-machine control firmware without RTOS overhead.
Recommended
Battery-Powered Sensor Nodes
For battery-powered sensor nodes such as wireless thermostats, smoke detectors, and remote controls, the PIC12C671T-04I/SM provides 6 I/O pins and a SAR ADC in a compact 8-SOIJ package while operating down to 3.0 V. Brown-out detection protects against low-cell lockup, and the internal RC oscillator eliminates external crystal cost and quiescent draw. The 1.75 KB OTP accommodates periodic-sleep firmware patterns and simple Modbus or proprietary RF-link framing. Pairing with a low-current sensor such as an NTC thermistor or a PIR element keeps total node current in the microamp range during sleep.
Recommended
Automotive Interior Accessories
The PIC12C671T-04I/SM's industrial -40C to +85C rating makes it usable in automotive interior accessories such as dome-light controllers, seat-occupancy detectors, and HVAC blend-door actuators. Its 8-bit ADC reads seat-pressure potentiometers and temperature probes, while 6 I/O pins drive small relays and LIN-bus bit-banged communication. The OTP architecture keeps unit cost low for high-volume accessory programs, and ICSP enables factory calibration after final assembly. For under-hood AEC-Q100 environments, migrate to a PIC16F or PIC18F automotive-grade part.
Recommended
Security Keypads and Access Control
The PIC12C671T-04I/SM suits security keypads, electronic locks, and access-control panels where 6 I/O pins can scan a 3x4 matrix via diode isolation or drive a buzzer, status LED, and magnetic-strike FET. Brown-out reset and watchdog timer provide the lockup-recovery required for unattended security hardware. The integrated ADC can monitor backup-battery voltage and detect tamper-switch resistance changes. OTP memory prevents firmware reverse-engineering from a decapped part, an advantage for code-protection-sensitive deployments. Pricing near $1.32 per unit keeps margin healthy on consumer-grade hardware.
Recommended
Simple Closed-Loop Fan/Pump Controllers
For closed-loop fan or pump speed controllers, the PIC12C671T-04I/SM uses its 8-bit ADC to read a thermistor or tachometer feedback and PWM-emulated outputs on the 6 I/O pins to drive a FET gate. The 4 MHz clock and 200 ns instruction cycle handle PID-like update loops at 1 kHz with margin to spare, and brown-out reset prevents undefined behavior during motor inrush transients. Designers can implement soft-start, stall detection, and overtemperature shutdown in 1.75 KB of OTP firmware without an RTOS. Pairing with a back-EMF sensing resistor enables sensorless BLDC control in cost-sensitive applications.
Recommended
LED Lighting Drivers and Indicators
The PIC12C671T-04I/SM drives LED indicator panels, RGB mood lighting, and decorative string-light controllers using 6 I/O pins and bit-banged PWM at 4 MHz. Its ADC reads ambient-light sensors for automatic brightness adjustment, while brown-out detection prevents flicker during AC-line brown-outs in mains-powered fixtures. The small 8-SOIJ footprint fits inside GU10 lamp bases and candle-bulb form factors, where every square millimeter matters. With OTP pricing around $1.32 in volume, designers can afford a dedicated MCU per lamp without inflating retail cost.
Recommended
Recommended Products Summary
Engineering reference data for PIC12C671T-04I/SM β comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC12C671-04I/SM | PIC12C671T-04E/SM | PIC12C672T-04I/SM | PIC12CE674T-04I/SM | PIC12C509A-04I/SM |
|---|---|---|---|---|---|---|
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Package | 8-SOIJ (SM) | 8-SOIJ (SM) - same | 8-SOIJ (SM) - same | 8-SOIJ (SM) - same | 8-SOIJ (SM) - same | 8-SOIJ (SM) - same |
| Program Memory | 1.75 KB OTP | 1.75 KB OTP | 1.75 KB OTP | 3.5 KB OTP | 3.5 KB OTP | 1.5 KB OTP |
| RAM Size | 128 bytes | 128 bytes | 128 bytes | 128 bytes | 128 bytes | 41 bytes |
| Data EEPROM | None | None | None | None | 128 bytes | None |
| Maximum Clock Speed | 4 MHz | 4 MHz | 4 MHz | 4 MHz | 4 MHz | 4 MHz |
| ADC | 8-bit, 4 channels | 8-bit, 4 channels | 8-bit, 4 channels | 8-bit, 4 channels | 8-bit, 4 channels | None |
| I/O Pins | 6 | 6 | 6 | 6 | 6 | 6 |
| Temperature Range | -40C to +85C (industrial) | -40C to +85C (industrial) | -40C to +125C (extended) | -40C to +85C (industrial) | -40C to +85C (industrial) | -40C to +85C (industrial) |
| Supply Voltage | 3.0 V to 5.5 V | 3.0 V to 5.5 V | 3.0 V to 5.5 V | 3.0 V to 5.5 V | 3.0 V to 5.5 V | 3.0 V to 5.5 V |
Key Differentiators
- Integrated 8-bit ADC with 4 channels in only 6 I/O pins (vs PIC12C509A-04I/SM)
- Double the code space versus PIC12C509A (vs PIC12C509A-04I/SM)
- More RAM for buffer-intensive applications (vs PIC12C509A-04I/SM)
Design Notes
Power supply design for the PIC12C671T-04I/SM should include a 100 nF decoupling capacitor placed within 5 mm of the VDD pin and a bulk capacitor (typically 10 uF tantalum or aluminum polymer) at the board entry point. The device draws relatively low current but its ADC can corrupt readings if VDD ripples more than 50 mV during conversion; a small ferrite bead or 10 ohm resistor between the analog and digital supplies improves noise immunity in sensor applications.
OTP memory cannot be erased or rewritten. Once a PIC12C671T-04I/SM is programmed, firmware bugs cannot be patched in the field. Always validate firmware on a Flash-based equivalent (such as PIC12F675 or PIC16F54) before committing to OTP production. Additionally, the MCLR pin (GP3) is shared with the programming voltage input - if your design drives this pin as a normal logic output, ensure the load cannot source current into VPP during ICSP or the part will fail programming.
The 8-SOIJ (SM) package uses J-leads with a slightly larger footprint than a standard SOIC-8. Allocate at least 1.0 mm of clearance around each lead for the solder fillet and 0.5 mm between adjacent leads to prevent bridging during reflow. The exposed die pad is not present on this package, but a continuous ground plane under the device still improves thermal dissipation and EMC immunity. Place the ICSP test points or pads on the board edge to allow programming without removing the MCU.
When using the PIC12C671T-04I/SM ADC for precision measurements, the analog inputs (AN0-AN3) should be bypassed with 100 nF capacitors if source impedance exceeds 10 kohm, to limit acquisition-time errors. The internal ADC sample-and-hold requires a minimum acquisition time of approximately 20 microseconds at 4 MHz. Configure the GPIO pins connected to analog signals as inputs with the digital input buffer disabled (ANSEL/CMCON registers) to prevent digital switching noise from coupling into the analog path.
Compliance Information
RoHS compliant per Microchip product page. Industrial temperature grade (-40C to +85C); NOT AEC-Q100 qualified for under-hood automotive. Lead-free SOIJ package per JEDEC J-STD-020.
