PIC16LC71T-04I/SO - 1.75KB EPROM MCU 4MHz SOIC-18 | Microchip
MPN: PIC16LC71T-04I/SO ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $2.55 | $2.55 |
| 10 | $2.3 | $23.00 |
| 100 | $2.1 | $210.00 |
| 500 | $1.92 | $960.00 |
| 1,000 | $1.75 | $1,750.00 |
PIC16LC71T-04I/SO Overview
A microcontroller (MCU) is a single-chip computer that integrates a CPU core, non-volatile program memory, RAM, and programmable peripherals on one die. The PIC16C7X family is part of Microchip's mid-range 8-bit architecture using a Harvard design with separate program and data buses; the LC7X variants specifically use CMOS-EPROM for one-time-programmable code storage and operate from a 3.0V-6.0V supply window optimized for low-power battery and industrial applications.
Key features include a 13-bit instruction word architecture (14-bit PIC mid-range), an 8-bit 4-channel successive-approximation ADC with conversion speed tied to the oscillator, an 8-bit Timer0 with prescaler, a 16-bit Timer1 with external crystal option, and an 8-bit Timer2. The 13 bidirectional I/O pins are arranged across two ports (RA and RB) with software-configurable direction. The wide 2.5V-5.5V supply range and 13 I/O lines let the part replace discrete logic plus an external ADC in cost-sensitive designs.
Typical applications include industrial sensor interfaces, low-power consumer white goods controls, automotive body electronics modules, HVAC thermostat controls, and battery-powered instrumentation. The integrated ADC and EPROM programmability make this MCU a common choice for retrofits of legacy PIC16C71 designs where the SOIC footprint is already on the PCB.
When designing with this part, note that EPROM cells require windowed packages or one-time-programming (OTP) on standard SOIC variants; the LC71 family does not support in-system reprogramming. The 4 MHz oscillator input can be a crystal, ceramic resonator, or external clock, and the ADC conversion clock must be derived from the system oscillator.
This page synthesizes distributor pricing, drop-in alternatives, and practical design notes not found in the manufacturer datasheet.
Drop-in alternatives for PIC16LC71T-04I/SO — 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 PIC16LC71T-04I/SO (same form factor and footprint) — differing in Program Memory Type, Core Architecture, Timers, Program Memory Size, ADC.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PIC16LC71T-04/SO
✅ Drop-In✓ In Stock
$2.45 / Unit
View Datasheet →PIC16LC71-04I/SO
✅ Drop-In✓ In Stock
$1.85 / Unit
View Datasheet →PIC16LC71-04/SO
✅ Drop-In✓ In Stock
$4.1 / Unit
View Datasheet →PIC16LC710T-04E/SS
✅ Drop-In✓ In Stock
$2.05 / Unit
View Datasheet →PIC16LC711T-04E/SO
✅ Drop-In✓ In Stock
$4.32 / Unit
View Datasheet →PIC16LC71T-04I/SO Maximum Ratings & Electrical Characteristics
| Architecture | PIC 8-bit RISC (Mid-range 14-bit instruction) |
| Program Memory Type | EPROM (OTP) |
| Program Memory Size | 1.75 KB (1K x 14) |
| RAM Size | 36 bytes |
| Data EEPROM | 0 bytes (no on-chip EEPROM) |
| Maximum Clock Speed | 4 MHz (20 MHz in datasheet DC figure for division) |
| Supply Voltage Range | 2.5 V to 6.0 V (typical 5 V) |
| I/O Pins | 13 |
| ADC | 8-bit, 4 channels (successive approximation) |
| Timers | Timer0 (8-bit + prescaler), Timer1 (16-bit), Timer2 (8-bit) |
| Watchdog Timer | Yes |
| Brown-out Reset | Yes |
| Operating Temperature Range | -40 C to +85 C (Industrial) |
| Package | 18-SOIC (0.300 inch, 7.62 mm) |
| Mounting Type | Surface Mount |
| RoHS Status | Compliant |
| Lead Free | Yes |
PIC16LC71T-04I/SO Pin Configuration
| Pin 1 | RA0/AN0 — Bidirectional I/O / ADC channel 0 |
| Pin 2 | RA1/AN1 — Bidirectional I/O / ADC channel 1 |
| Pin 3 | RA2/AN2 — Bidirectional I/O / ADC channel 2 |
| Pin 4 | RA3/AN3 — Bidirectional I/O / ADC channel 3 |
| Pin 5 | RA4/T0CKI — Bidirectional I/O / Timer0 clock input (open-drain) |
| Pin 6 | OSC1/CLKIN — Crystal oscillator input / external clock input |
| Pin 7 | OSC2/CLKOUT — Crystal oscillator output / clock output |
| Pin 8 | MCLR/VPP — Master clear reset (active low) / programming voltage |
| Pin 9 | VSS — Ground |
| Pin 10 | VDD — Positive supply voltage |
| Pin 11 | RB0/INT — Bidirectional I/O / external interrupt input |
| Pin 12 | RB1 — Bidirectional I/O |
| Pin 13 | RB2 — Bidirectional I/O |
| Pin 14 | RB3 — Bidirectional I/O |
| Pin 15 | RB4 — Bidirectional I/O |
| Pin 16 | RB5 — Bidirectional I/O |
| Pin 17 | RB6 — Bidirectional I/O |
| Pin 18 | RB7 — Bidirectional I/O |
Typical Applications
PIC16LC71T-04I/SO is suitable for 6 applications: Industrial Sensor Signal Conditioning, HVAC Thermostat Control, Battery-Powered Instrumentation, Automotive Body Electronics (Legacy), White Goods Control Panels, Retrofit / Legacy Drop-In Replacement.
Industrial Sensor Signal Conditioning
The PIC16LC71T-04I/SO's integrated 4-channel 8-bit ADC and 13 I/O pins make it well suited for industrial sensor interfaces where a small MCU plus analog front-end is needed. The 4 MHz clock gives 1 microsecond instruction cycle, enough throughput for polling 4 sensors at 100 Hz with simple averaging. The wide 2.5V-6V supply range lets it run directly from 5V industrial rails or from 3.3V battery-backed sources. The industrial -40C to +85C rating covers factory-floor environments without derating. Use it as a cost-effective replacement for legacy PIC16C71 boards.
Recommended
HVAC Thermostat Control
The PIC16LC71T-04I/SO fits HVAC thermostat designs because the 8-bit ADC reads thermistor or analog temperature sensors, the 13 I/O pins drive relays and triacs for fan/heat/cool stages, and the 4 MHz oscillator is sufficient for hysteresis control loops without DSP. The wide 2.5V-6V range tolerates rectified 24VAC supplies with simple regulation. Brown-out reset prevents latch-up on brown-out events common in HVAC wiring. Watchdog timer recovers from EMI-induced firmware hangs in electrically noisy thermostat environments.
Recommended
Battery-Powered Instrumentation
The PIC16LC71T-04I/SO is suitable for battery-powered handheld instruments because the CMOS-EP process and 2.5V minimum supply give low operating current, while the 16-bit Timer1 with sleep-mode external crystal option allows ultra-low-power timekeeping between ADC samples. The 36 bytes of RAM is enough for a few floating-point scalars in fixed-point math. Brown-out reset protects battery cells from deep discharge damage. The industrial temp rating supports outdoor and automotive handheld applications.
Recommended
Automotive Body Electronics (Legacy)
The PIC16LC71T-04I/SO fits legacy automotive body modules where the OEM has locked the PCB footprint and toolchain on the PIC16C71 family. The -40C to +85C industrial range covers most cabin applications; for under-hood applications an AEC-Q100-qualified part would be required. The integrated ADC reads analog switches and resistive sensors without external components. Brown-out reset and watchdog timer provide the resilience demanded by automotive electrical environments including load-dump transients.
Recommended
White Goods Control Panels
The PIC16LC71T-04I/SO serves washing-machine, dishwasher, and microwave user-interface panels where the MCU reads keypad matrix, drives multiplexed LED or 7-segment displays, and times motor control relays. The 13 I/O lines handle a 4x4 keypad plus 8 LED/segment lines with one I/O to spare. The wide supply range accepts rectified-transformer 12V or 24V after a small regulator. The -40C to +85C rating covers appliance ambient temperatures in unventilated enclosures.
Recommended
Retrofit / Legacy Drop-In Replacement
The PIC16LC71T-04I/SO is the canonical Microchip drop-in for PIC16C71-based designs that need long-term component continuity. The die, pinout, and electrical characteristics are identical to the original C71; only the EPROM/CMOS process letter changed. The T/R suffix indicates modern tape-and-reel packing compatible with high-speed SMT lines. Use this MPN to refresh old BOMs without PCB rework, and pair with the PIC16LC711 family for parts needing more RAM.
Recommended
Recommended Products Summary
Engineering reference data for PIC16LC71T-04I/SO — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC16LC71T-04/SO | PIC16LC71-04I/SO | PIC16LC71-04/SO | PIC16LC710T-04E/SS | PIC16LC711T-04E/SO |
|---|---|---|---|---|---|---|
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Package | 18-SOIC | 18-SOIC | 18-SOIC | 18-SOIC | 18-SOIC | 18-SOIC |
| Program Memory | 1.75 KB EPROM | 1.75 KB EPROM | 1.75 KB EPROM | 1.75 KB EPROM | 0.875 KB EPROM | 1.75 KB EPROM |
| RAM | 36 bytes | 36 bytes | 36 bytes | 36 bytes | 36 bytes | 68 bytes |
| Clock Speed | 4 MHz | 4 MHz | 4 MHz | 4 MHz | 4 MHz | 4 MHz |
| Supply Voltage | 2.5 V to 6.0 V | 2.5 V to 6.0 V | 2.5 V to 6.0 V | 2.5 V to 6.0 V | 2.5 V to 6.0 V | 2.5 V to 6.0 V |
| ADC | 8-bit, 4 channels | 8-bit, 4 channels | 8-bit, 4 channels | 8-bit, 4 channels | None | 8-bit, 4 channels |
| Operating Temperature | -40 C to +85 C (Industrial) | -40 C to +85 C (Industrial) | -40 C to +85 C (Industrial) | 0 C to +70 C (Commercial) | -40 C to +125 C (Extended) | -40 C to +125 C (Extended) |
| Carrier Packaging | Tape & Reel | Tube | Tube | Tube | Tape & Reel | Tape & Reel |
| Unit Price (qty 1) | $2.55 | $2.55 (typical) | $2.50 (typical) | $2.30 (typical) | $2.40 (typical) | $2.65 (typical) |
Key Differentiators
- Tape-and-reel carrier for high-speed SMT assembly (vs PIC16LC71T-04/SO)
- Industrial -40C to +85C temperature grade (vs PIC16LC71-04/SO)
- Higher memory ceiling within family (vs PIC16LC710T-04E/SS)
- Integrated 4-channel 8-bit ADC (vs PIC16LC710T-04E/SS)
Design Notes
Place a 100 nF ceramic decoupling capacitor as close to the VDD pin (pin 10) as possible, with traces short and direct to the VSS pin (pin 9). Add a 10 uF bulk capacitor on the same supply node within 1 cm of the MCU. The brown-out reset is internally calibrated but the datasheet recommends a minimum VDD rise time of 0.05 V/ms; very slow supply ramps (e.g. large RC time constants on battery circuits) may cause BOR-induced reset loops. For wide-input applications an external LDO such as MCP1700 provides a clean 3.3V or 5V rail.
The PIC16LC71T-04I/SO is an OTP/EPROM part; the SOIC package cannot be erased or reprogrammed. Each unit can be programmed exactly once. Windowed CERDIP packages (e.g. PIC16LC71T-04I/P with quartz window) are required for development iteration. Configuration bits must be set correctly at programming time - in particular the oscillator selection (XT, HS, LP, RC) and the watchdog enable state - because OTP parts cannot be reconfigured later. For prototyping choose a Flash-based PIC16F-series upgrade path.
The MCLR/VPP pin (pin 8) requires a 10 kohm pull-up to VDD for normal operation; programming pulses apply 13V to this pin during EPROM programming. A 100 nF cap from MCLR to VDD filters noise on reset. The OSC1/OSC2 pins (pins 6 and 7) should be routed symmetrically to the crystal or resonator with short traces and a ground guard ring; keep digital signal traces away from these traces to avoid jitter. RA4 is an open-drain output requiring an external pull-up resistor.
Compliance Information
RoHS compliant per Microchip product page. Not AEC-Q100 qualified; for automotive under-hood applications choose an AEC-Q100 part. Halogen-free status not explicitly published for this legacy part. REACH compliance per Microchip statement.
