PIC16LF721-I/SO - 16MHz 8-bit MCU, 7KB Flash, 20-SOIC | Microchip
MPN: PIC16LF721-I/SO ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $2.34 | $2.34 |
| 10 | $2.1 | $21.00 |
| 100 | $1.85 | $185.00 |
| 500 | $1.62 | $810.00 |
| 1,000 | $1.44 | $1,440.00 |
PIC16LF721-I/SO Overview
What is a PIC16 microcontroller? The PIC16 family is Microchip's mid-range 8-bit microcontroller line, positioned between the baseline PIC10/12/16 and the high-performance PIC18/PIC24 families. These devices use a Harvard RISC architecture with separate program and data buses, single-cycle instruction execution, and a compact instruction set optimized for embedded control. PIC16 MCUs typically target cost-sensitive, low-power applications such as sensor nodes, consumer appliances, and industrial controllers where deterministic behavior and small footprint outweigh raw compute throughput.
The PIC16LF721 features 18 programmable I/O pins, an Enhanced Universal Synchronous/Asynchronous Receiver/Transmitter (EUSART), two analog comparators with selectable reference, a 12-bit ADC with up to 16 channels, and an integrated LCD driver supporting up to 36 segments. It operates across 2.3V to 3.6V with active current of approximately 250 µA at 1 MHz and sleep currents below 100 nA in retention mode.
The architecture combines a RISC CPU core with peripheral modules that share I/O pins via flexible multiplexing, allowing designers to optimize pin usage against feature sets. The 16 MHz max internal oscillator and 4x PLL option (64 MHz operation with 4x PLL multiplier, 16 MHz CPU clock input) deliver adequate headroom for digital filtering, communication protocols, and sensor fusion tasks.
Typical applications include low-power sensor interfaces with LCD readout, battery-powered instrumentation, handheld consumer devices, HVAC control modules, and home automation endpoints where its segment-LCD driver, multi-channel ADC, and nanoWatt sleep currents are particularly valuable.
When designing with this device, prioritize decoupling (100 nF near VDD, 10 µF bulk on AVSS/VDD rails), keep ADC traces short, and leverage the peripheral pin select (PPS) feature to route digital functions to available I/O without PCB rework.
This page synthesizes verified distributor pricing, drop-in pin-compatible alternatives in the same SOIC-20 footprint, and practical design notes not found in the standalone manufacturer datasheet.
Drop-in alternatives for PIC16LF721-I/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 PIC16LF721-I/SO (same form factor and footprint) — differing in Package, Timers, Operating Temperature, ADC, Core Architecture.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PIC16LF720-I/SO
✅ Drop-In✓ In Stock
$0.85 / Unit
View Datasheet →PIC16F721-I/SO
✅ Drop-In✓ In Stock
$0.92 / Unit
View Datasheet →PIC16LF1938-I/SO
✅ Drop-In✓ In Stock
$1.74 / Unit
View Datasheet →PIC16LF720T-I/SO
✅ Drop-In✓ In Stock
$0.86 / Unit
View Datasheet →PIC16LF727-I/SO
✅ Drop-In📋 Reference alternative (not in catalog)
PIC16LF721-I/SO Maximum Ratings & Electrical Characteristics
| Core Architecture | PIC16 8-bit RISC |
| Program Memory | 7 KB (4K x 14 words) Flash |
| RAM | 256 bytes |
| Max CPU Speed | 16 MHz (16 MIPS) |
| Supply Voltage | 2.3 V to 3.6 V |
| I/O Pins | 18 |
| ADC | 12-bit, up to 16 channels |
| Comparators | 2 analog comparators |
| Timers | Multiple 8/16-bit (TMR0, TMR1, TMR2) |
| Communication | EUSART, MSSP (SPI/I2C) |
| LCD Driver | Integrated, up to 36 segments |
| Package | 20-pin SOIC (0.295"/7.50 mm width) |
| Operating Temperature | -40 C to +85 C (Industrial) |
| Low-Power Technology | nanoWatt XLP |
| Mounting Type | Surface Mount |
| Pitch | 1.27 mm |
| RoHS Status | Compliant |
PIC16LF721-I/SO Pin Configuration
| Pin 1 | RA0/AN0/C1IN+/SEG12 — PORTA bit 0 / ADC input / Comparator input / LCD segment |
| Pin 2 | RA1/AN1/C1IN-/SEG13 — PORTA bit 1 / ADC input / Comparator input / LCD segment |
| Pin 3 | RA2/AN2/VREF-/C1OUT/SEG14 — PORTA bit 2 / ADC input / VREF- / Comparator output / LCD segment |
| Pin 4 | RA3/AN3/VREF+/C1IN+/SEG15 — PORTA bit 3 / ADC input / VREF+ / Comparator input / LCD segment |
| Pin 5 | RA4/AN4/C2OUT/T0CKI/SEG16 — PORTA bit 4 / ADC input / Comparator output / Timer0 clock / LCD segment |
| Pin 6 | RA5/AN5/C2IN+/SS/SEG17 — PORTA bit 5 / ADC input / Comparator input / SPI slave select / LCD segment |
| Pin 7 | RA6/OSC2/CLKO/SEG18 — PORTA bit 6 / Oscillator output / Clock output / LCD segment |
| Pin 8 | RA7/OSC1/CLKI/SEG19 — PORTA bit 7 / Oscillator input / Clock input / LCD segment |
| Pin 9 | VSS — Ground reference |
| Pin 10 | VDD — Positive supply voltage (2.3 V to 3.6 V) |
| Pin 11 | RB0/AN12/C2IN-/INT/SEG0 — PORTB bit 0 / ADC input / Comparator input / External interrupt / LCD segment |
| Pin 12 | RB1/AN10/C1IN+/SEG1 — PORTB bit 1 / ADC input / Comparator input / LCD segment |
| Pin 13 | RB2/AN8/C2IN+/SEG2 — PORTB bit 2 / ADC input / Comparator input / LCD segment |
| Pin 14 | RB3/AN9/C2IN-/SEG3 — PORTB bit 3 / ADC input / Comparator input / LCD segment |
| Pin 15 | RB4/AN11/C1IN-/SEG4 — PORTB bit 4 / ADC input / Comparator input / LCD segment |
| Pin 16 | RB5/AN13/C1IN+/SEG5 — PORTB bit 5 / ADC input / Comparator input / LCD segment |
| Pin 17 | RB6/ICSPCLK/SEG6 — PORTB bit 6 / In-circuit serial programming clock / LCD segment |
| Pin 18 | RB7/ICSPDAT/SEG7 — PORTB bit 7 / In-circuit serial programming data / LCD segment |
| Pin 19 | AVSS — Analog ground reference |
| Pin 20 | AVDD — Analog positive supply voltage |
Typical Applications
PIC16LF721-I/SO is suitable for 6 applications: Battery-Powered Sensor Node with LCD Readout, Home Appliance Control Board, Industrial Sensor Transmitter, Handheld Consumer Device with LCD, HVAC Thermostat Control, Smart Home Sensor Endpoint.
Battery-Powered Sensor Node with LCD Readout
The PIC16LF721-I/SO is well-suited for battery-powered sensor nodes that need a local segmented LCD for value display. The integrated LCD driver supports up to 36 segments, eliminating the need for an external driver IC and reducing BOM cost. Its nanoWatt XLP technology delivers sleep currents below 100 nA, allowing multi-year operation on a single coin cell. Combined with the 12-bit ADC and 16 MIPS CPU, the device can sample sensors, run averaging filters, and refresh the LCD with minimal power overhead. Engineers typically pair the MCU with a thermistor or MEMS sensor on the ADC channel and a 4- to 8-digit segment LCD. The 2.3 V to 3.6 V supply range matches two-AA alkaline or single-cell Li-ion chemistries directly.
Recommended
Home Appliance Control Board
The PIC16LF721-I/SO is a strong fit for home appliances such as coffee makers, washing machines, and microwave ovens that require HMI feedback via segmented LCDs. The integrated segment driver drives up to 36 LCD segments directly, enabling mode indicators, timer readouts, and status icons. The 12-bit ADC handles temperature and humidity sensing, the EUSART enables communication with sub-modules or smart-home bridges, and the comparators support safety shutoff on overcurrent conditions. The 20-pin SOIC package is easy to hand-solder for prototype runs, while the 16 MIPS CPU supports button debouncing, encoder reading, and PID-like control loops. Industrial -40 C to +85 C temperature rating covers appliance environment requirements.
Recommended
Industrial Sensor Transmitter
For 4-20 mA loop-powered or low-voltage industrial sensor transmitters, the PIC16LF721-I/SO provides the right balance of ADC precision, communication interfaces, and low-power operation. The 12-bit ADC with 16 channels supports multi-sensor input from bridges, RTDs, or 4-20 mA shunts. The EUSART interfaces with HART modems or RS-485 transceivers, while the SPI/I2C MSSP connects to external EEPROM for calibration data. The 2.3 V to 3.6 V supply is compatible with regulated 3.3 V industrial rails. The 7 KB flash is sufficient for linearization tables, calibration routines, and Modbus RTU protocol stacks. The industrial temperature range and SOIC-20 footprint support harsh environment PCB layouts with conformal coating compatibility.
Recommended
Handheld Consumer Device with LCD
Handheld consumer devices such as remote controls with displays, portable health monitors, and digital thermometers benefit from the PIC16LF721-I/SO's segment LCD driver, low-power XLP technology, and small SOIC-20 footprint. The 12-bit ADC reads sensor inputs with sufficient precision for health-monitoring applications, while the 256-byte RAM supports basic protocol stacks and user interface state machines. The nanoWatt XLP sleep mode extends battery life to multiple years on a single CR2032 coin cell. The internal 16 MHz oscillator eliminates external crystals in cost-sensitive designs, and the integrated EUSART supports firmware updates via UART bootloaders. Engineers can also leverage the integrated timers for precise button-debounce and backlight control.
Recommended
HVAC Thermostat Control
The PIC16LF721-I/SO fits HVAC thermostat designs that need to drive a segmented LCD, sample temperature from NTC thermistors, and switch relays or triacs. The integrated LCD driver supports the typical thermostat display with current temperature, setpoint, mode icons, and fan status, eliminating an external LCD driver and reducing cost. The 12-bit ADC delivers 0.1 C resolution from a 10 kΩ NTC divider, while comparators detect over-temperature conditions for safety shutoff. The EUSART connects to Wi-Fi or sub-GHz radio modules for smart-home integration. Operating temperature of -40 C to +85 C handles indoor/outdoor HVAC environments, and the SOIC-20 package supports automated pick-and-place assembly lines.
Recommended
Smart Home Sensor Endpoint
The PIC16LF721-I/SO is a strong match for battery-powered smart-home sensor endpoints such as door/window sensors, leak detectors, and occupancy sensors that need long battery life and optional segmented LCD readouts. The nanoWatt XLP sleep mode below 100 nA enables 5+ year operation on a single CR2032, while the EUSART supports low-power radio modules like Sub-GHz transceivers. The 12-bit ADC reads analog sensors, and the integrated timers handle wake-on-interrupt and pulse counting. The 7 KB flash accommodates encrypted communication stacks and over-the-air update bootloaders. The compact 20-SOIC footprint fits inside small sensor enclosures without compromising PCB layout density.
Recommended
Recommended Products Summary
Engineering reference data for PIC16LF721-I/SO — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC16LF720-I/SO | PIC16F721-I/SO | PIC16LF1938-I/SO | PIC16LF720T-I/SO | PIC16LF727-I/SO |
|---|---|---|---|---|---|---|
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Package | 20-SOIC | 20-SOIC - same | 20-SOIC - same | 28-SOIC - extended | 20-SOIC - same | 28-SOIC - extended |
| Flash Memory | 7 KB | 4 KB | 7 KB | 28 KB | 4 KB | 14 KB |
| RAM | 256 B | 256 B | 256 B | 2 KB | 256 B | 1 KB |
| Max CPU Speed | 16 MHz (16 MIPS) | 16 MHz (16 MIPS) | 16 MHz (16 MIPS) | 32 MHz | 16 MHz (16 MIPS) | 20 MHz |
| Supply Voltage | 2.3 V to 3.6 V | 2.3 V to 3.6 V | 2.0 V to 5.5 V | 1.8 V to 3.6 V | 2.3 V to 3.6 V | 1.8 V to 3.6 V |
| I/O Pins | 18 | 18 | 18 | 24 | 18 | 36 |
| LCD Driver Segments | Up to 36 segments | Up to 36 segments | Up to 36 segments | No LCD driver | Up to 36 segments | Up to 64 segments |
| ADC Resolution | 12-bit, 16 channels | 12-bit, 12 channels | 12-bit, 16 channels | 10-bit, 17 channels | 12-bit, 12 channels | 12-bit, 14 channels |
| Low-Power Sleep Current | <100 nA (nanoWatt XLP) | <100 nA (nanoWatt XLP) | <1 uA | <50 nA (nanoWatt XLP) | <100 nA (nanoWatt XLP) | <100 nA (nanoWatt XLP) |
Key Differentiators
- Largest flash memory in PIC16LF7xx 20-SOIC family (vs PIC16LF720-I/SO)
- Integrated 36-segment LCD driver with nanoWatt XLP (vs PIC16LF1938-I/SO)
- Wider operating voltage for 5 V industrial designs (vs PIC16F721-I/SO)
Design Notes
Estimated: At 16 MHz CPU clock and 3.3 V supply, active current is approximately 250 uA per MHz (~4 mA total). For battery designs, sleep mode reduces consumption to under 100 nA with RAM retention, enabling multi-year operation on a 220 mAh coin cell. Place a 100 nF decoupling capacitor within 5 mm of each VDD/AVDD pin and a 10 uF bulk capacitor on the main supply rail. Enable nanoWatt XLP features by setting proper configuration bits for internal weak pull-ups and unused peripheral disable.
Route the analog ADC inputs (AN0-AN13) as short traces away from switching signals and digital I/O. Connect AVSS to VSS at a single point near the MCU to avoid ground loops. For LCD applications, the segment traces can be routed under the LCD connector with adequate spacing from backplane commons. The SOIC-20 footprint at 1.27 mm pitch supports hand-soldering with standard 0.5 mm tip irons and is compatible with automated pick-and-place assembly.
Do not exceed the absolute maximum VDD of 4.0 V (per datasheet) on the LF variant, or latch-up may occur. Ensure MCLR pin has a proper pull-up (typically 10 kohm) for normal operation, as floating MCLR can cause unpredictable resets. For in-circuit serial programming (ICSP), reserve pins RB6/ICSPCLK and RB7/ICSPDAT - do not connect them to low-impedance loads that prevent programming. Always configure unused I/O as outputs and set them to a defined state to minimize current leakage in sleep mode.
Compliance Information
RoHS and REACH compliant per Microchip product page. Industrial temperature grade -40 C to +85 C. Not AEC-Q100 qualified - for automotive applications consider PIC16F721-E/SO variants.
