PIC16LC71-04/P - 8-bit 4MHz OTP MCU w/ ADC | Microchip | DIP-18
MPN: PIC16LC71-04/P ✗ End of Life| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $2.64 | $2.64 |
| 10 | $2.4 | $24.00 |
| 100 | $2.18 | $218.00 |
| 500 | $1.95 | $975.00 |
| 1,000 | $1.78 | $1,780.00 |
PIC16LC71-04/P Overview
A microcontroller (MCU) is a single-chip computer that integrates a CPU, memory (program + data), and peripheral interfaces onto one IC. The PIC16LC71 family belongs to Microchip's mid-range PIC16C architecture, which adds an 8-channel 8-bit ADC to the baseline PIC16C5X/PIC16CXX core. The "LC" prefix denotes the low-power CMOS variant, optimized for battery and energy-conscious designs, and the "71" indicates the A/D-equipped sub-family. Within the broader taxonomy, the device sits at: microcontroller -> 8-bit MCU -> PIC mid-range -> PIC16C71X sub-family -> semiconductor IC.
Key features of the PIC16LC71-04/P include 4MHz maximum operating frequency (200ns instruction cycle), 1.75KB of one-time-programmable (OTP) program memory organized as 1K x 14 words, 36 bytes of general-purpose RAM, 13 bi-directional I/O pins, an integrated 4-channel 8-bit ADC with internal reference options, and a 5V operating supply typical of the 16C family. The "04" speed grade specifies the 4MHz fOSC rating, and the "/P" suffix designates the plastic 18-pin PDIP package. The device executes instructions in a single cycle (200ns @ 4MHz) with only 35 single-word instructions.
Typical applications include low-cost embedded control, sensor signal conditioning via the on-chip ADC, appliance controllers, simple closed-loop PID/thermostat designs, and battery-powered instruments where the LC variant's lower current draw provides a measurable advantage. The 8-bit ADC and modest RAM/pin count also suit this part for prototyping with hand-written assembly routines.
When designing with the PIC16LC71-04/P, ensure the OTP memory limitation is acceptable for your production volume (OTP cannot be re-programmed in-circuit). The integrated ADC requires proper input impedance matching and reference decoupling; consult the manufacturer datasheet typical application circuit for the recommended RC network on the ADC reference pins.
This page synthesizes distributor pricing, drop-in alternatives within the same 18-pin PDIP footprint, and practical design notes not found in the manufacturer datasheet alone.
Drop-in alternatives for PIC16LC71-04/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 PIC16LC71-04/P (same form factor and footprint) — differing in Package, Mounting Type, Core, Instruction Cycle Time, Maximum Clock Frequency.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PIC16C71-04/P
✅ Drop-In ⚠️ Specs Unverified📋 Reference alternative (not in catalog)
PIC16C711-04/P
✅ Drop-In ⚠️ Specs Unverified✓ In Stock
$2.54 / Unit
View Datasheet →PIC16C715-04/P
✅ Drop-In ⚠️ Specs Unverified📋 Reference alternative (not in catalog)
PIC16C712-04/P
✅ Drop-In ⚠️ Specs Unverified📋 Reference alternative (not in catalog)
PIC16C716-04/P
✅ Drop-In ⚠️ Specs Unverified📋 Reference alternative (not in catalog)
PIC16F71-I/P
✅ Drop-In ⚠️ Specs Unverified📋 Reference alternative (not in catalog)
PIC16LC71-04/P Maximum Ratings & Electrical Characteristics
| Family | PIC PIC16C |
| Core | 8-bit PIC mid-range |
| Core Processor | PIC |
| Maximum Clock Frequency | 4 MHz |
| Instruction Cycle Time | 200 ns @ 4 MHz |
| Program Memory Type | OTP (One-Time Programmable) |
| Program Memory Size | 1.75 KB (1K x 14) |
| RAM Size | 36 bytes |
| Number of I/O Pins | 13 |
| ADC | Integrated 8-bit ADC |
| Supply Voltage | 5 V (typical) |
| Package | 18-pin PDIP (0.300 inch / 7.62 mm pitch) |
| Mounting Type | Through-Hole |
| Instruction Set | 35 single-word instructions |
| Architecture | RISC, fully static CMOS |
| MSL Level | Not applicable (through-hole PDIP) |
PIC16LC71-04/P Pin Configuration
| Pin 1 | RA2/AN2/VREF — GPIO RA2 / analog input channel 2 / ADC voltage reference |
| Pin 2 | RA3/AN3 — GPIO RA3 / analog input channel 3 |
| Pin 3 | RA4/T0CKI — GPIO RA4 / Timer0 clock input |
| Pin 4 | MCLR — Master clear (reset) input, active low |
| Pin 5 | VSS — Ground reference |
| Pin 6 | RB0/INT — GPIO RB0 / external interrupt input |
| Pin 7 | RB1 — GPIO RB1 |
| Pin 8 | RB2 — GPIO RB2 |
| Pin 9 | RB3 — GPIO RB3 |
| Pin 10 | RB4 — GPIO RB4 |
| Pin 11 | RB5 — GPIO RB5 |
| Pin 12 | RB6 — GPIO RB6 |
| Pin 13 | RB7 — GPIO RB7 |
| Pin 14 | VDD — Positive supply voltage (+5V typical) |
| Pin 15 | OSC2/CLKOUT — Oscillator crystal output / clock output |
| Pin 16 | OSC1/CLKIN — Oscillator crystal input / external clock input |
| Pin 17 | RA0/AN0 — GPIO RA0 / analog input channel 0 |
| Pin 18 | RA1/AN1 — GPIO RA1 / analog input channel 1 |
Typical Applications
PIC16LC71-04/P is suitable for 7 applications: Battery-Powered Sensor Interface, Appliance Control (White Goods), Educational / Hobby Microcontroller, Simple Closed-Loop Thermostat, Automotive Interior Lighting Controller, Low-Cost Industrial Timer / Counter, Legacy Equipment Repair / Maintenance.
Battery-Powered Sensor Interface
The PIC16LC71-04/P is well suited for battery-powered sensor interface modules thanks to its LC low-power CMOS core and integrated 8-bit ADC. With 13 I/O pins and 4 MHz operation, it can sample up to 4 analog sensor channels and run simple linearization routines while drawing minimal quiescent current. The 1.75 KB OTP program memory is sufficient for fixed sensor calibration tables, and the 36-byte RAM supports short rolling averages without external memory. Designers should use the LC variant specifically for sleep-mode current budgets below 100 uA.
Recommended
Appliance Control (White Goods)
The PIC16LC71-04/P fits low-cost appliance controllers - washing machine timers, dishwasher cycles, microwave oven keypads - where its 18-pin PDIP package is easy to hand-prototype and its OTP memory is acceptable for high-volume fixed-function products. The integrated 8-bit ADC reads temperature sensors, water-level switches, and potentiometers; the 13 I/O lines drive relays, LEDs, and seven-segment displays. The 4 MHz speed grade handles routine sequencing with cycle times that fit within the 200 ns instruction budget.
Recommended
Educational / Hobby Microcontroller
The PIC16LC71-04/P is widely used in undergraduate embedded systems courses and hobbyist projects due to its 35-instruction RISC architecture, 18-pin PDIP through-hole package (easy to breadboard and socket), and low cost. Students learn assembly language fundamentals on the PIC mid-range core, then use the on-chip ADC for basic analog projects like voltmeters, light meters, and simple data loggers. The OTP variant teaches students about one-time-programmable memory economics versus Flash-based parts.
Recommended
Simple Closed-Loop Thermostat
The PIC16LC71-04/P runs single-loop PID thermostats for HVAC and refrigeration cabinets by reading an NTC thermistor via its 8-bit ADC and switching a relay or TRIAC via GPIO. The 4 MHz speed grade provides enough compute for 1 Hz temperature updates with proportional and integral terms. The OTP memory holds the calibrated setpoint and hysteresis parameters; the LC variant's low quiescent current keeps standby power low. Hysteresis-band control uses 36 bytes of RAM for the moving-average filter and PI state.
Recommended
Automotive Interior Lighting Controller
Although NRND, the PIC16LC71-04/P is still found in legacy automotive interior lighting modules where it sequences dome-light fade-in, courtesy lamps, and puddle-light PWM dimming via its 13 I/O pins. The integrated ADC monitors ambient light sensors to enable automatic headlight response; the 4 MHz core runs the fade curve with sufficient resolution. Note: the standard LC71 is not AEC-Q100 qualified; for new automotive designs, the PIC16F716 with automotive grade suffix is preferred.
Recommended
Low-Cost Industrial Timer / Counter
The PIC16LC71-04/P powers simple industrial counter/timer modules where it counts pulses from a sensor (via T0CKI on RA4), accumulates events, and displays results on a multiplexed LED or 7-segment display. The integrated ADC is repurposed for analog setpoint reading (e.g. threshold voltage), while digital I/O drives the display. The OTP memory locks the configuration for tamper resistance, which matters in regulated industrial environments.
Recommended
Legacy Equipment Repair / Maintenance
The PIC16LC71-04/P remains a critical component for maintaining and repairing legacy industrial and consumer equipment originally manufactured in the 1990s and 2000s. Because many of these systems were designed around the PIC16C71X family with no firmware update path, replacement boards must use the exact same OTP part to maintain functional equivalence. Distributors including LCSC and DigiKey still stock this part for legacy MRO demand. Cross-reference alternatives in the same PDIP-18 footprint allow engineers to source replacements when the original part is unavailable.
Recommended
Recommended Products Summary
Engineering reference data for PIC16LC71-04/P — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC16C71-04/P | PIC16C711-04/P | PIC16C715-04/P | PIC16C712-04/P | PIC16C716-04/P | PIC16F71-I/P |
|---|---|---|---|---|---|---|---|
| Package | PDIP-18 (0.300 inch) | PDIP-18 (0.300 inch) - same | PDIP-18 (0.300 inch) - same | PDIP-18 (0.300 inch) - same | PDIP-18 (0.300 inch) - same | PDIP-18 (0.300 inch) - same | PDIP-18 (0.300 inch) - same |
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Program Memory Type | OTP (1.75 KB / 1K x 14) | OTP (1.75 KB / 1K x 14) | OTP (1.75 KB + 128B EEPROM data) | OTP (2K x 14) | OTP (1K x 14) | OTP (2K x 14) | Flash (1.75 KB) |
| RAM Size | 36 bytes | 36 bytes | 68 bytes | 128 bytes | 128 bytes | 128 bytes | 36 bytes |
| Max Clock Frequency | 4 MHz | 4 MHz | 4 MHz | 4 MHz | 4 MHz | 4 MHz | 20 MHz |
| ADC | 8-bit, 4 channels | 8-bit, 4 channels | 8-bit, 4 channels | 8-bit, 8 channels | 8-bit, 4 channels | 8-bit, 8 channels | 8-bit, 4 channels |
| I/O Pins | 13 | 13 | 13 | 13 | 13 | 13 | 13 |
| Power Variant | LC (low-power CMOS) | C (standard CMOS, no LC) | C (standard CMOS) | C (standard CMOS) | C (standard CMOS) | C (standard CMOS) | F (Flash, low-power) |
| Reprogrammability | No (OTP) | No (OTP) | No (OTP) | No (OTP) | No (OTP) | No (OTP) | Yes (Flash, 100k erase cycles) |
Key Differentiators
- Low-power LC variant within PIC16C71X family (vs PIC16C71-04/P)
- Original 4-channel 8-bit ADC configuration (vs PIC16C715-04/P)
- Minimal RAM footprint for simple loops (vs PIC16C711-04/P)
- Through-hole PDIP for prototyping and repair (vs PIC16F716-I/P)
Design Notes
OTP memory limitation: the PIC16LC71-04/P uses one-time-programmable program memory, which cannot be erased or re-programmed in-circuit. This means any firmware bug discovered after programming cannot be patched via software update. For prototyping, always use a windowed CERDIP or a Flash equivalent (e.g. PIC16F71) first, then commit to OTP only after firmware is fully validated. Estimated firmware development cost: 1-2 engineer-weeks for typical 1 KB code footprint.
Power supply decoupling: place a 0.1 uF ceramic capacitor as close as possible to the VDD pin (pin 14) with the ground return to VSS (pin 5). The LC variant is sensitive to VDD ripple above 50 mV, which can cause ADC measurement noise and brown-out resets. For ADC accuracy, also decouple the VREF reference input with 10 uF tantalum in parallel with 0.1 uF ceramic. Estimated BOM cost: < $0.20 for the decoupling network.
Oscillator layout: when using an external crystal or ceramic resonator between OSC1 (pin 16) and OSC2 (pin 15), keep the trace length under 5 mm and route the traces over a continuous ground plane to avoid EMI coupling. Capping the crystal traces with ground guard rings on both sides reduces radiated emissions by approximately 6-10 dB. The LC variant's lower drive strength makes it slightly less tolerant of stray capacitance than the standard C variant.
ADC input impedance: the on-chip 8-bit ADC of the PIC16LC71-04/P has a maximum recommended source impedance of 10 kOhm to preserve ADC accuracy. For high-impedance sensors (e.g. thermistor dividers > 50 kOhm), buffer the input with an op-amp follower (MCP6002 or similar) to avoid ADC sampling errors. Acquisition time must also be extended in software via the ADC configuration register for high-impedance sources.
MCLR pin pull-up: pin 4 (MCLR) requires an external pull-up resistor (typically 10 kOhm to VDD) to prevent spurious resets from noise. For high-noise industrial environments, add a 100 nF ceramic capacitor from MCLR to VSS to filter out fast transients. Without proper MCLR biasing, the MCU may experience intermittent resets that appear as firmware bugs.
Compliance Information
RoHS and lead-free status depends on date code/lot - many original PDIP OTP OTP parts predate RoHS regulations. For new designs requiring RoHS, use the PIC16F71 (Flash, RoHS compliant) instead. AEC-Q100 not qualified; the standard PIC16LC71-04/P is not for new automotive applications.
