PIC16C71T-20I/SO - 8-Bit 20MHz OTP MCU w/ ADC | Microchip
MPN: PIC16C71T-20I/SO β End of Life| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $4.2 | $4.20 |
| 10 | $3.78 | $37.80 |
| 100 | $3.15 | $315.00 |
| 500 | $2.65 | $1,325.00 |
| 1,000 | $2.2 | $2,200.00 |
PIC16C71T-20I/SO Overview
An 8-bit microcontroller (MCU) is a small computer-on-a-chip containing a CPU, memory, and peripherals. The PIC16C71 belongs to the mid-range PIC family, sitting between baseline (PIC10/12/16) and enhanced mid-range (PIC16F1xxx) tiers. As a ROM/OTP device, it is programmed once and is typically chosen for cost-sensitive, high-volume products where code is fixed for the lifetime of the unit.
Key features include a 20 MHz maximum clock, 1.75 KB OTP program memory, 36 bytes of data RAM, an integrated 8-bit 4-channel analog-to-digital converter, 13 I/O pins, and a wide 3.0V to 6.0V operating voltage range. The 'T' suffix denotes tape-and-reel packaging, '20' indicates the 20 MHz speed grade, 'I' marks the industrial -40C to +85C temperature grade, and 'SO' specifies the 18-pin SOIC package.
The device uses a Harvard architecture with separate program and data buses, RISC instruction set (35 instructions), and a 14-bit instruction word. The integrated ADC supports direct analog sensor interfacing without external components, while the industrial temperature range and CMOS low-power design suit it for unattended, battery-tolerant environments.
Typical applications include low-cost consumer appliances, sensor signal conditioning nodes, industrial control sub-modules, automotive body-fitting interior subsystems, and battery-powered instrumentation. The integrated ADC simplifies analog sensor reading while the small 18-pin footprint aids compact PCB layouts.
When designing with the PIC16C71T-20I/SO, note that this is an OTP part - code cannot be re-programmed in-circuit. For prototyping, use the windowed JW version, and for production with firmware upgrades, consider a Flash-based equivalent such as PIC16F716.
This page consolidates distributor inventory, drop-in PIC16C71T-20I/SO cross-references, and design-in guidance not aggregated in the original Microchip datasheet, helping engineers compare substitutes and source the part quickly.
Drop-in alternatives for PIC16C71T-20I/SO 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 PIC16C71T-20I/SO (same form factor and footprint) β differing in ADC, Package, Program Memory Type, Timers, Maximum Clock Frequency.
Quick Comparison Tool β Select alternative parts for side-by-side comparison:
PIC16C71-20I/SO
β Drop-Inπ Reference alternative (not in catalog)
PIC16C71T-20/SO
β Drop-Inπ Reference alternative (not in catalog)
PIC16C71T-04/SO
β Drop-Inβ In Stock
$1.79 / Unit
View Datasheet βPIC16C711-20I/SO
β Drop-Inβ In Stock
$1.95 / Unit
View Datasheet βPIC16F716-I/SO
β Drop-Inπ Reference alternative (not in catalog)
PIC16C716-20I/P
β Drop-Inβ In Stock
$3.05 / Unit
View Datasheet βPIC16C71T-20I/SO Maximum Ratings & Electrical Characteristics
| Family | PIC16CXX mid-range |
| Core | 8-bit PIC RISC |
| Program Memory Type | OTP (One-Time Programmable) |
| Program Memory Size | 1.75 KB (1K x 14) |
| Data RAM | 36 bytes |
| Maximum Clock Frequency | 20 MHz |
| Operating Voltage | 3.0 V to 6.0 V |
| I/O Pins | 13 |
| ADC | 8-bit, 4 channels |
| Instruction Set | 35 instructions, 14-bit word |
| Architecture | Harvard, RISC |
| Package | 18-pin SOIC (7.50 mm / 0.295 in width) |
| Packaging | Tape and Reel (T suffix) |
| Temperature Grade | Industrial, -40C to +85C |
| Speed Grade | 20 MHz (20 suffix) |
PIC16C71T-20I/SO Pin Configuration
| Pin 1 | RA2/AN2 β Port A bit 2 / analog input 2 |
| Pin 2 | RA3/AN3 β Port A bit 3 / analog input 3 / VREF+ |
| Pin 3 | RA4/T0CKI β Port A bit 4 / Timer0 clock input |
| Pin 4 | MCLR β Master Clear (reset, active low) |
| Pin 5 | VSS β Ground |
| Pin 6 | OSC1/CLKIN β Oscillator input / external clock |
| Pin 7 | OSC2/CLKOUT β Oscillator output / clock out |
| Pin 8 | RB0/INT β Port B bit 0 / external interrupt |
| Pin 9 | RB1 β Port B bit 1 |
| Pin 10 | RB2 β Port B bit 2 |
| Pin 11 | RB3 β Port B bit 3 |
| Pin 12 | RB4 β Port B bit 4 |
| Pin 13 | RB5 β Port B bit 5 |
| Pin 14 | RB6 β Port B bit 6 |
| Pin 15 | RB7 β Port B bit 7 |
| Pin 16 | VDD β Positive supply voltage |
| Pin 17 | RA0/AN0 β Port A bit 0 / analog input 0 |
| Pin 18 | RA1/AN1 β Port A bit 1 / analog input 1 |
Typical Applications
PIC16C71T-20I/SO is suitable for 6 applications: Low-Cost Consumer Appliance Control, Analog Sensor Signal Conditioning, Industrial Control Sub-Modules, Automotive Body Interior Subsystems, Battery-Powered Instrumentation, Legacy Firmware Replication.
Low-Cost Consumer Appliance Control
The PIC16C71T-20I/SO fits low-cost consumer appliance control with its 1.75 KB OTP program memory, 4-channel 8-bit ADC, and 13 I/O pins. The integrated ADC reads sensor inputs directly, eliminating an external converter and reducing BOM cost. The 20 MHz clock (5 MIPS peak throughput per Microchip datasheet) handles motor timing, button debouncing, and LED multiplexing in washers, rice cookers, or simple HVAC controls. OTP memory is a security advantage because the firmware cannot be read back, protecting proprietary control algorithms. Industrial -40C to +85C temperature grade survives the under-cabinet thermal envelope of hobbyist living spaces.
Recommended
Analog Sensor Signal Conditioning
The PIC16C71T-20I/SO is well-suited for analog sensor signal conditioning nodes, where its integrated 4-channel 8-bit ADC directly digitizes thermistor, photodiode, or potentiometer signals. The wide 3.0V to 6.0V supply range allows it to run directly from a 3.3V or 5V analog rail, simplifying the power tree. The 13 I/O pins drive indicator LEDs, relay drivers, or UART links to a host controller. PIC RISC architecture executes control loops with deterministic timing required for sensor sampling. Tape-and-reel packaging supports high-volume SMT assembly on sensor node PCBs, keeping per-unit assembly cost low.
Recommended
Industrial Control Sub-Modules
The PIC16C71T-20I/SO serves industrial control sub-modules such as relay drivers, contact-debouncers, or remote I/O expanders where 1.75 KB of OTP code is sufficient. The industrial -40C to +85C temperature grade handles factory-floor thermal envelopes, and the 18-pin SOIC package mounts easily on small PLC daughter boards. Its 20 MHz clock speed drives Modbus RTU ASCII framing at common baud rates with margin for protocol overhead. The integrated ADC supports 4-20 mA loop readback via a shunt resistor. Microchip long-term supply has shifted to Flash parts, but installed PIC16C71 designs continue operating in legacy industrial systems.
Recommended
Automotive Body Interior Subsystems
The PIC16C71T-20I/SO handles automotive body interior subsystems such as seat controllers, mirror adjusters, or interior lighting, where its compact 18-pin SOIC footprint, ADC, and 13 I/O pins suffice for low-bandwidth H-bridge driving and switch sensing. The industrial temperature grade handles cabin thermal swings, though full AEC-Q100 automotive qualification would require the Q-classified variant. The integrated ADC reads potentiometer wiper voltages for analog position feedback. OTP code lock prevents aftermarket firmware tampering, a property automotive Tier-1 suppliers value. For new automotive designs, PIC16F716-Q variants are the AEC-Q100 path.
Recommended
Battery-Powered Instrumentation
The PIC16C71T-20I/SO suits battery-powered instrumentation such as handheld multimeters, environmental loggers, or wireless sensor nodes, thanks to its CMOS low-power design and wide 3.0V to 6.0V supply range. The 20 MHz clock can be software-throttled at runtime to minimize quiescent draw during sleep intervals, extending battery life. The integrated 8-bit ADC reads battery voltage and analog sensors without an external converter, and 13 I/O pins drive LCD segments or low-power radios. OTP memory suits single-configuration high-volume products, securing calibration tables in firmware. Tape-and-reel packaging eases SMT assembly for compact handheld PCBs.
Recommended
Legacy Firmware Replication
The PIC16C71T-20I/SO is uniquely qualified for legacy firmware replication projects, where bit-exact compatibility with the original PIC16C71 silicon is mandatory and re-validation costs exceed Flash benefits. OTP memory guarantees the original code cannot be reverse-engineered, protecting vendors whose legacy code was developed for OTP parts only. The 18-pin SOIC package matches the original PCB footprint, preserving mechanical form-factor. Engineers maintaining long-life products (industrial controls, certified medical instruments, government systems) continue sourcing PIC16C71 OTP parts to keep installed bases running. Tape-and-reel packaging supports OEM-style high-volume assembly for sustaining engineering lines.
Recommended
Recommended Products Summary
Engineering reference data for PIC16C71T-20I/SO β comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC16C71-20I/SO | PIC16C71T-20/SO | PIC16C71T-04/SO | PIC16C711-20I/SO | PIC16F716-I/SO |
|---|---|---|---|---|---|---|
| Package | 18-pin SOIC (7.50 mm) | 18-pin SOIC (same) | 18-pin SOIC (same) | 18-pin SOIC (same) | 18-pin SOIC (same) | 18-pin SOIC (same) |
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | |
| Program Memory Type | OTP | OTP (same) | OTP (same) | EPROM (windowed for prototype) | Flash (reprogrammable) | |
| Program Memory Size | 1.75 KB (1K x 14) | 1.75 KB (same) | 1.75 KB (same) | 1.75 KB (same) | 8 KB (4x larger) | |
| Maximum Clock Frequency | 20 MHz | 20 MHz | 20 MHz | 4 MHz (-80%) | 20 MHz | |
| Temperature Grade | Industrial -40C to +85C | Industrial (same) | Commercial 0C to +70C | Industrial (same) | ||
| ADC | 8-bit, 4 channels | 8-bit, 4 channels (same) | 8-bit, enhanced | |||
| Packaging Format | Tape & Reel (T suffix) | Tube (no T suffix) | Tube (no T suffix) | |||
| Lifecycle Status | Obsolete | Obsolete | Active |
Key Differentiators
- Tape-and-reel format for high-volume SMT assembly (vs PIC16C71-20I/SO)
- Industrial -40C to +85C temperature grade (vs PIC16C71T-20/SO)
- OTP code security for proprietary firmware (vs PIC16F716-I/SO)
Design Notes
PIC16C71T-20I/SO uses OTP memory - code cannot be erased or rewritten once programmed. For development and prototyping, use the windowed PIC16C71J variant or migrate to Flash-based PIC16F716-I/SO to avoid scrapping boards due to code bugs. Verify the entire firmware image before programming production units. OTP programming time is typically a few seconds per part; budget factory programming time into NRE cost.
Estimated: power consumption at 20 MHz with VDD=5V is approximately 15-20 mA active. For battery-powered designs, use SLEEP instruction to drop current to microamp levels between sensor reads. The ADC draws bias current during conversion; disable it between samples to minimize power. Place a 100 nF decoupling capacitor as close to VDD (pin 16) as possible, plus 10 uF bulk capacitance on the supply rail.
The 18-pin SOIC has 1.27 mm pin pitch. Route oscillator traces (OSC1/OSC2) short and shield them from digital switching lines to reduce EMI coupling. Place the MCLR pull-up close to the IC and route the reset trace away from high-current paths. The analog inputs (AN0-AN3) should be guarded by ground traces to reject digital noise from adjacent I/O. Keep ADC traces away from the oscillator and switching power traces.
Estimated: power dissipation at 20 MHz and 5V with all I/O toggling is below 100 mW, well within the 18-pin SOIC thermal envelope of approximately 100 C/W theta-JA. No heatsink is required even at industrial +85C ambient. However, ensure surrounding components (especially power regulators) do not crowd the MCU and obstruct airflow. For enclosed assemblies, derate clock frequency above 70C ambient if the application runs sustained high duty cycles.
Compliance Information
Compliance status not confirmed in provided data. The 'I' suffix denotes industrial temperature grade, not AEC-Q100 automotive qualification. For automotive applications, use Q-suffix variants.
