PIC12LC671-04/SM - 4MHz 8-Bit CMOS MCU with ADC | Microchip
MPN: PIC12LC671-04/SM โ End of Life| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $2.85 | $2.85 |
| 10 | $2.56 | $25.60 |
| 100 | $2.27 | $227.00 |
| 500 | $1.95 | $975.00 |
| 1,000 | $1.72 | $1,720.00 |
PIC12LC671-04/SM Overview
A microcontroller (MCU) is a single-chip computer that integrates a CPU, memory (program + data), and peripherals such as ADC, timers and I/O ports. Within Microchip's taxonomy, the PIC12C67x family belongs to the PIC10/12/16 mid-range 8-bit architecture, which sits beneath the PIC18 high-tier 8-bit family and the PIC24/dsPIC 16-bit families in Microchip's broader 8-bit -> 16-bit -> 32-bit microcontroller hierarchy. The mid-range core uses a 14-bit instruction word and Harvard architecture, delivering deterministic interrupt response and predictable timing for real-time control applications.
Key features include four-channel 8-bit ADC, two analog comparators, a 16-bit timer/counter with programmable prescaler, an 8-bit timer/counter, internal watchdog timer with on-chip RC oscillator, and 4 MHz maximum operating frequency. The device supports in-circuit serial programming (ICSP) via GP0/GP1, allowing firmware to be programmed after PCB assembly. Power management features include selectable oscillator modes and a power-saving sleep mode with wake-up via I/O change or watchdog timer overflow.
Typical applications include battery-powered sensor interfaces, automotive body electronics (where the "LC" extended voltage range is valuable), consumer appliance controllers, simple closed-loop fan control, and low-cost analog data acquisition. The combination of on-chip ADC and very low cost makes this part a common choice for replacement of discrete analog signal chains in cost-sensitive products.
When designing with this device, engineers should note that OTP memory cannot be reprogrammed; for prototyping the JW (ceramic windowed) or -I (industrial temperature) variants are typically preferred. The SOIJ package offers a slightly smaller footprint than standard SOIC while remaining hand-solderable with appropriate tooling.
Drop-in alternatives for PIC12LC671-04/SM โ 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 PIC12LC671-04/SM (same form factor and footprint) โ differing in Operating Temperature, Package, RoHS Status, Timers, Watchdog Timer.
Quick Comparison Tool โ Select alternative parts for side-by-side comparison:
PIC12LC671-04I/SM
โ Drop-In๐ Reference alternative (not in catalog)
PIC12C671-04/SM
โ Drop-In๐ Reference alternative (not in catalog)
PIC12C671-04I/SM
โ Drop-In โ ๏ธ ๅๆฐๅพ ้ช่ฏ๐ Reference alternative (not in catalog)
PIC12CE674-04/SM
โ Drop-In โ ๏ธ ๅๆฐๅพ ้ช่ฏ๐ Reference alternative (not in catalog)
PIC12C672-04/SM
โ Drop-In โ ๏ธ ๅๆฐๅพ ้ช่ฏโ In Stock
$3.1 / Unit
View Datasheet โPIC12F675-I/SM
โ Drop-In๐ Reference alternative (not in catalog)
PIC12LC671-04/SM Maximum Ratings & Electrical Characteristics
| Core Architecture | PIC 8-bit RISC (mid-range, 14-bit instruction word) |
| Program Memory | 1.75 KB (1K x 14) OTP |
| Data RAM | 128 bytes |
| EEPROM (data) | None (CE variants only) |
| Max CPU Frequency | 4 MHz |
| I/O Pins | 6 (GPIO) |
| ADC | 8-bit, 4 channels |
| Comparators | 2 analog comparators |
| Timers | 1x 16-bit Timer/Counter + 1x 8-bit Timer/Counter |
| Watchdog Timer | Yes, with internal RC oscillator |
| In-Circuit Programming | ICSP supported via GP0/GP1 |
| Package | 8-pin SOIJ (SM), 5.30 mm body width |
| Operating Temperature | Commercial: 0C to +70C (industrial -I variant: -40C to +85C) |
| RoHS Status | Compliant (post-2005 manufacture) |
PIC12LC671-04/SM Pin Configuration
| Pin 1 | VDD โ Positive supply voltage (2.5V to 5.5V for LC variant) |
| Pin 2 | GP5/OSC1/CLKIN โ General-purpose I/O / oscillator input / external clock input |
| Pin 3 | GP4/OSC2/CLKOUT โ General-purpose I/O / oscillator output / clock output |
| Pin 4 | GP3/MCLR/VPP โ General-purpose I/O / master clear reset (active low) / ICSP programming voltage |
| Pin 5 | GP2/AN2/T0CKI/INT โ General-purpose I/O / analog channel 2 / Timer0 clock input / external interrupt |
| Pin 6 | GP1/AN1/VREF/ICSPCLK โ General-purpose I/O / analog channel 1 / ADC voltage reference / ICSP clock |
| Pin 7 | GP0/AN0/ICSPDAT โ General-purpose I/O / analog channel 0 / ICSP data |
| Pin 8 | VSS โ Ground reference |
Typical Applications
PIC12LC671-04/SM is suitable for 6 applications: Battery-Powered Sensor Interface, Simple Closed-Loop Fan Controller, Automotive Body Electronics, Consumer Appliance Control, Low-Cost Analog Data Acquisition, Smart Home Sensor Node.
Battery-Powered Sensor Interface
The PIC12LC671-04/SM is well-suited to battery-powered sensor interfaces because its 2.5 V minimum supply voltage enables direct operation from 2x AA alkaline cells across their full discharge curve. The integrated 8-bit 4-channel ADC reads thermistor, photocell, or voltage-divider sensors with no external signal conditioning, while the 16-bit timer/counter drives PWM output for actuator or LED control. At 4 MHz the device draws only a few hundred microamperes active, and the sleep mode with watchdog wake-up achieves quiescent currents below 1 microampere for multi-year battery life in wireless sensor nodes and remote controls.
Recommended
Simple Closed-Loop Fan Controller
In small fan controllers, the PIC12LC671-04/SM uses its on-chip 8-bit ADC to read a thermistor or external temperature sensor and adjusts PWM duty cycle on one GPIO to drive the fan MOSFET. The two analog comparators can implement hardware over-temperature protection independent of firmware, providing fail-safe shutdown if firmware locks up. The 4 MHz core is sufficient for PID control loops at typical thermal time constants, and the 8-SOIJ package fits into space-constrained fan hubs. Industrial-temperature variants are recommended for fan controller PCBs mounted near hot heatsinks.
Recommended
Automotive Body Electronics
The PIC12LC671-04/SM is commonly used in low-end automotive body electronics such as interior lighting controllers, simple switch debouncers, and seat position indicators. Its ability to operate directly from a 5 V regulated rail and read multiple analog switch positions via the ADC eliminates discrete analog multiplexer ICs. The 16-bit timer can debounce mechanical switches or generate precise timing for relay drivers. For underhood applications, the industrial-temperature PIC12LC671-04I/SM variant is recommended. Note: this part is not AEC-Q100 qualified, so designers should validate the full BOM against their automotive EMC and environmental requirements.
Recommended
Consumer Appliance Control
The PIC12LC671-04/SM is widely used in cost-sensitive consumer appliances such as coffee makers, toaster ovens, and small kitchen devices where its integrated ADC reads temperature or humidity sensors and the 16-bit timer generates precise cooking-cycle timing. The 1.75 KB OTP memory holds simple state-machine firmware, and the 8-SOIJ package fits in compact appliance enclosures. The 2.5 V minimum supply allows operation from rectified 5 V supplies without additional regulation. Industrial-temperature variants support under-cabinet mounting where ambient temperature may exceed commercial ratings during operation.
Recommended
Low-Cost Analog Data Acquisition
The PIC12LC671-04/SM serves as a low-cost 4-channel analog data logger for HVAC sensors, environmental monitors, and industrial process inputs. Its 8-bit ADC samples at rates up to several tens of kilohertz, sufficient for thermocouple cold-junction compensation or 4-20 mA loop readout when paired with a sense resistor. With 128 bytes of RAM, the device can buffer several seconds of averaged data before requiring host transfer via a UART-implemented GPIO bit-bang or dedicated communication pin. The combination of ADC, two comparators, and timers in a single 8-pin package replaces multiple discrete analog ICs in cost-optimized designs.
Recommended
Smart Home Sensor Node
The PIC12LC671-04/SM is a strong fit for first-generation smart home sensor nodes such as door/window contact sensors, water leak detectors, and simple occupancy sensors. Its 2.5 V minimum supply voltage enables direct operation from CR2032 lithium coin cells, while the watchdog timer with internal RC oscillator handles wake-up cycles for multi-year battery life. The integrated 8-bit ADC reads resistive sensors directly, and the 6 GPIO pins control a low-power RF transmitter or drive a piezo buzzer. For new designs, Microchip recommends the PIC12F675 successor with flash memory and internal oscillator for BOM reduction.
Recommended
Recommended Products Summary
Engineering reference data for PIC12LC671-04/SM โ comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC12LC671-04I/SM | PIC12C671-04/SM | PIC12C671-04I/SM | PIC12F675-I/SM |
|---|---|---|---|---|---|
| Brand | 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 |
| Program Memory | 1.75 KB OTP | 1.75 KB OTP | 1.75 KB OTP | 1.75 KB OTP | 1.75 KB Flash |
| Data RAM | 128 bytes | 128 bytes | 128 bytes | 128 bytes | 64 bytes |
| ADC Resolution | 8-bit | 8-bit | 8-bit | 8-bit | 10-bit |
| Operating Voltage Range | 2.5V to 5.5V | 2.5V to 5.5V | 4.0V to 6.0V | 4.0V to 6.0V | 2.0V to 5.5V |
| Temperature Grade | Commercial (0C to +70C) | Industrial (-40C to +85C) | Commercial | Industrial | Industrial |
| Internal Oscillator | No | No | No | No | Yes (4 MHz) |
Key Differentiators
- Extended low-voltage operation down to 2.5 V (vs PIC12C671-04/SM)
- Industrial temperature grade option (vs PIC12LC671-04/SM (this part, commercial grade))
- Flash memory and internal oscillator in successor part (vs PIC12F675-I/SM)
Design Notes
Estimated: The PIC12LC671 supply current at 4 MHz active is approximately 2 mA at 5 V (10 mW). In sleep mode with watchdog disabled, current drops to under 1 microampere. For battery-powered designs, use the watchdog timer with internal RC oscillator (~38 kHz typical) to periodically wake the MCU, achieving average current below 10 microamperes depending on wake duty cycle. Decouple VDD with a 100 nF ceramic capacitor placed within 5 mm of pin 1.
Estimated: Route the ICSP programming signals GP0 (ICSPDAT) and GP1 (ICSPCLK) to an in-circuit programming header with a 100 kohm pull-down on MCLR/VPP to prevent spurious resets. Keep the MCLR trace short to minimize noise pickup. Place the decoupling capacitor on VDD close to pin 1, and provide a solid ground plane under the SOIJ package to reduce EMI. When using the ADC, route analog signals (GP0-GP2) away from digital switching signals to minimize coupling.
Estimated: Do not confuse the LC and C variants - the LC operates from 2.5 V to 5.5 V while the standard C requires 4.0 V to 6.0 V. OTP memory can be programmed only once, so validate all firmware on a JW (windowed) ceramic prototype before committing to production. When migrating to PIC12F675 as Microchip recommends, note that the F variant has 64 bytes RAM (vs 128) and a 10-bit ADC (vs 8-bit), which may require firmware adjustments. The ICSP programming connector must be isolated from the rest of the circuit during programming to prevent load-induced programming failures.
Compliance Information
RoHS and lead-free per Microchip product page. Not AEC-Q100 qualified - the industrial-temperature I variant is not automotive-qualified either. For AEC-Q100 designs, use PIC16F1823 or similar.
