PIC16LF721-E/SO - 8-Bit MCU, 7KB Flash, 16MHz, 20-SOIC | Microchip
MPN: PIC16LF721-E/SO ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $1.85 | $1.85 |
| 10 | $1.66 | $16.60 |
| 100 | $1.48 | $148.00 |
| 500 | $1.32 | $660.00 |
| 1,000 | $1.18 | $1,180.00 |
PIC16LF721-E/SO Overview
A microcontroller is a single-chip computer that combines a CPU, memory, and peripherals. Within the broader hierarchy, an 8-bit MCU like the PIC16LF721 sits below 16-bit and 32-bit MCUs in raw throughput, but excels in deterministic interrupt latency, low cost, and ultra-low sleep current for battery applications. The PIC16LF721 belongs to Microchip's PIC16F family of mid-range 8-bit microcontrollers, which sit between smaller PIC10/12 baseline parts and larger PIC18 high-performance 8-bit parts in the Microchip portfolio.
Key features of the PIC16LF721 include 18 general-purpose I/O pins (shared with peripherals), two 8-bit timers plus one 16-bit timer, a 10-bit ADC with internal voltage reference, comparators, enhanced PWM, and nanoWatt XLP technology that drops sleep current below typical values for coin-cell applications. The /S0 industrial temperature grade variant operates from -40C to +125C.
The PIC16LF721 is built on Microchip's enhanced mid-range 8-bit core with a 14-bit instruction word and 8-level hardware stack. The integrated ADC, comparators, and PWM modules share I/O pins with digital functions, allowing designers to remap peripherals to suit PCB layout. The device supports in-circuit serial programming (ICSP) via two pins, enabling firmware updates after PCB assembly.
Typical applications include low-power IoT sensor nodes, battery-powered remote controls, consumer appliances, lighting controls, and small motor-driver front ends. The wide 2.0V-3.6V operating range allows direct connection to two AA alkaline or single Li-ion cells without additional regulators.
When designing with this device, reserve the ICSP/ICD pins (RB6/RB7) for in-circuit programming - do not assign them to application loads that would block debug access. For battery-powered designs, leverage the nanoWatt XLP sleep modes and use the internal 16 MHz HFINTOSC to minimize external component count.
This page synthesizes distributor stock, drop-in package equivalents, and practical design notes not found in the manufacturer datasheet alone.
Drop-in alternatives for PIC16LF721-E/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-E/SO (same form factor and footprint) — differing in Package, Timers, ADC, Operating Temperature, RoHS Status.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PIC16F721-E/SO
✅ Drop-In📋 Reference alternative (not in catalog)
PIC16LF720-E/SO
✅ Drop-In📋 Reference alternative (not in catalog)
PIC16LF722-E/SO
✅ Drop-In✓ In Stock
$0.78 / Unit
View Datasheet →PIC16LF720-I/SO
✅ Drop-In✓ In Stock
$0.85 / Unit
View Datasheet →PIC16LF720T-I/SO
✅ Drop-In✓ In Stock
$0.86 / Unit
View Datasheet →PIC16LF720-E/SS
✅ Drop-In✓ In Stock
$1.18 / Unit
View Datasheet →PIC16LF1938-I/SO
✅ Drop-In ⚠️ Specs Unverified✓ In Stock
$1.74 / Unit
View Datasheet →PIC16LF721-E/SO Maximum Ratings & Electrical Characteristics
| Product Series | PIC16F (PIC16LF721) |
| Core Architecture | 8-bit PIC Enhanced Mid-Range |
| Program Memory | 7 KB Flash (4K x 14 words) |
| Data SRAM | 256 bytes |
| Maximum CPU Speed | 16 MHz (16 MIPS) |
| Supply Voltage (VDD) | 2.0 V to 3.6 V |
| I/O Pins | 18 |
| ADC | 10-bit, up to 17 channels |
| Timers | 2 x 8-bit + 1 x 16-bit |
| Communication | USART, MSSP (SPI / I2C) |
| Comparators | Yes |
| PWM | Enhanced PWM, multiple channels |
| Internal Oscillator | 16 MHz HFINTOSC, 31 kHz LFINTOSC |
| Low-Power Technology | nanoWatt XLP |
| ICSP / ICD | Yes (RB6/RB7) |
| Operating Temperature | -40C to +125C (E = Extended) |
| Package | 20-pin SOIC (SO), 7.50 mm body width |
| Mounting Type | Surface Mount |
| RoHS Status | Compliant (lead-free) |
| MSL Level | 1 (unlimited) |
PIC16LF721-E/SO Pin Configuration
| Pin 1 | MCLR — Master Clear (reset) input, programming voltage input |
| Pin 2 | RA0 — PORTA bit 0, AN0, ULPWU |
| Pin 3 | RA1 — PORTA bit 1, AN1 |
| Pin 4 | RA2 — PORTA bit 2, AN2, CVREF |
| Pin 5 | RA3 — PORTA bit 3, AN3, VREF+ |
| Pin 6 | RA4 — PORTA bit 4, T0CKI, AN4 |
| Pin 7 | RA5 — PORTA bit 5, AN5, VREF-, SS |
| Pin 8 | VSS — Ground reference |
| Pin 9 | RA7 — PORTA bit 7, OSC1 |
| Pin 10 | RA6 — PORTA bit 6, OSC2, CLKIN |
| Pin 11 | RC0 — PORTC bit 0, AN8, SOSCO |
| Pin 12 | RC1 — PORTC bit 1, AN9, SOSCI, CCP2 |
| Pin 13 | RC2 — PORTC bit 2, AN10, CCP1 |
| Pin 14 | RC3 — PORTC bit 3, AN11, SCL, SCK |
| Pin 15 | RC4 — PORTC bit 4, AN12, SDA, SDI |
| Pin 16 | RC5 — PORTC bit 5, AN13, SDO |
| Pin 17 | RC6 — PORTC bit 6, AN14, TX, CK |
| Pin 18 | RC7 — PORTC bit 7, AN15, RX, DT |
| Pin 19 | VSS — Ground reference |
| Pin 20 | VDD — Positive supply voltage (2.0-3.6 V) |
Typical Applications
PIC16LF721-E/SO is suitable for 6 applications: Battery-Powered IoT Sensor Node, Consumer Remote Control, Small Home Appliance Controller, LED Lighting Controller, Industrial Sensor Transmitter, Portable Medical Monitor Accessory.
Battery-Powered IoT Sensor Node
The PIC16LF721-E/SO is well suited for coin-cell or 2x AA battery sensor nodes because its 2.0-3.6 V VDD range accepts the battery stack directly without an LDO, and nanoWatt XLP sleep current typically drops below 100 nA in deep sleep. With a 16 MHz HFINTOSC, designs wake periodically to sample a sensor via the 10-bit ADC and transmit via I2C or USART, then return to sleep. The 256 B SRAM and 7 KB Flash comfortably hold state-machine firmware plus small protocol stacks. Designers should budget SRAM carefully for any buffered sensor data and use LFINTOSC for ultra-low-power timing.
Recommended
Consumer Remote Control
Infrared or RF remote controls benefit from the PIC16LF721-E/SO's low active current, integrated 16 MHz internal oscillator (eliminating the external crystal), and 18 flexible I/O to drive a keypad matrix and IR LED. The enhanced PWM outputs can modulate the IR carrier directly, while nanoWatt XLP lets the unit idle for years on a coin cell. The 20-SOIC package is easily hand-solderable for prototype builds, and ICSP allows firmware updates post-assembly. For designs needing more GPIO, step up to PIC16LF722-E/SO within the same footprint.
Recommended
Small Home Appliance Controller
Coffee makers, fans, small kitchen appliances, and HVAC zone controllers commonly use a PIC16LF721-E/SO as the central MCU. The 10-bit ADC reads temperature or humidity sensors, the comparators implement over-current protection on motor drive circuits, and the enhanced PWM channels generate variable-speed drive signals for brushed DC motors. The 2.0-3.6 V range allows operation from a regulated 3.3 V supply shared with Wi-Fi/BLE modules. Industrial -40C to +125C temperature grade handles under-cabinet and garage installations.
Recommended
LED Lighting Controller
Architectural and decorative LED controllers use the PIC16LF721-E/SO for PWM-driven dimming across multiple channels with smooth color-mixing algorithms. The enhanced PWM module provides 10-bit resolution at low frequencies, while the comparators can fold back current on LED over-temperature events. With 18 I/O, the part drives several independent LED strings and accepts DMX or 0-10 V dimming inputs via USART or ADC. nanoWatt XLP modes let the controller sleep between dimming commands for energy compliance.
Recommended
Industrial Sensor Transmitter
Industrial 4-20 mA loop-powered transmitters benefit from the PIC16LF721-E/SO's 2.0-3.6 V operation (fits inside a 4-20 mA loop budget) and -40C to +125C extended temperature grade. The integrated 10-bit ADC digitizes sensor inputs at adequate resolution for most process-control loops, while the USART outputs HART or Modbus RTU data on top of the analog signal. nanoWatt XLP sleep modes let the transmitter idle between requests. The 20-SOIC package handles the thermal stress of field-mounted enclosures.
Recommended
Portable Medical Monitor Accessory
Glucose meters, pulse oximeter accessories, and small handheld diagnostic tools use the PIC16LF721-E/SO for sensor interface and display control. The 10-bit ADC reads optical or electrochemical sensors with adequate precision for accessory-grade devices, while the 18 I/O drive segment LCDs or low-resolution OLED displays. The 2.0-3.6 V operation supports direct Li-ion cell connection, and nanoWatt XLP enables standby currents suitable for medical device standby budgets. Note: for primary diagnostic devices use higher-performance PIC24 or dsPIC families.
Recommended
Recommended Products Summary
Engineering reference data for PIC16LF721-E/SO — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC16F721-E/SO | PIC16LF720-E/SO | PIC16LF722-E/SO | PIC16LF720-I/SO | PIC16LF1938-I/SO |
|---|---|---|---|---|---|---|
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Package | 20-SOIC (SO) | 20-SOIC (SO) - same | 20-SOIC (SO) - same | 20-SOIC (SO) - same | 20-SOIC (SO) - same | 20-SOIC (SO) - same |
| Flash Memory | 7 KB | 7 KB | 4 KB (-43%) | More Flash | 4 KB (-43%) | 28 KB (+300%) |
| SRAM | 256 B | 256 B | 192 B (-25%) | More SRAM | 192 B (-25%) | 2 KB (+700%) |
| Max Clock Speed | 16 MHz / 16 MIPS | 16 MHz / 16 MIPS | 16 MHz / 16 MIPS | 16 MHz / 16 MIPS | 16 MHz / 16 MIPS | 32 MHz / 32 MIPS |
| Supply Voltage (VDD) | 2.0 V to 3.6 V | 2.0 V to 5.5 V | 2.0 V to 3.6 V | 2.0 V to 3.6 V | 2.0 V to 3.6 V | 1.8 V to 3.6 V |
| Temperature Grade | -40C to +125C (Extended) | -40C to +125C (Extended) | -40C to +125C (Extended) | -40C to +125C (Extended) | -40C to +85C (Industrial) | -40C to +85C (Industrial) |
| I/O Pins | 18 | 18 | 18 | 18 | 18 | 17 |
Key Differentiators
- Extended temperature grade -40C to +125C (vs PIC16LF720-I/SO)
- 7 KB Flash - 75% more code space than PIC16LF720 (vs PIC16LF720-E/SO)
- Low-voltage optimized 2.0-3.6 V operation (vs PIC16F721-E/SO)
Design Notes
Place a 0.1 uF decoupling capacitor as close as possible to the VDD pin (pin 20) and a bulk 1-10 uF tantalum or ceramic capacitor near the IC. The PIC16LF721-E/SO draws brief current spikes during Flash programming and ADC conversion events, so local bulk capacitance prevents VDD droop. For battery operation, switch the part into Sleep via the SLEEP instruction to leverage nanoWatt XLP sleep currents that typically fall below 100 nA, then wake on Watchdog Timer overflow or external interrupt.
Keep the ICSP/ICD pins (RB6/RA6 and RB7/RA7 on this package, or PGC/PGD in newer variants) routed to accessible header pads without intervening series resistors or FET switches, otherwise in-circuit programming will fail. Use a 10 kohm pull-up on MCLR (pin 1) to VDD through a diode for proper reset behavior. Reserve RA0 and RA1 as analog inputs if the design uses the ADC - avoid assigning digital outputs to these pins.
Do not assume the PIC16LF721 runs at 5 V - the LF (low-voltage) variant maxes out at 3.6 V; applying 5 V will damage the part. For 5 V designs, use PIC16F721-E/SO instead. Configuration bits must be set correctly (FOSC, WDTE, PWRTE, MCLRE) or the part will fail to start; verify config words in MPLAB X before programming. Watchdog Timer should be enabled in noisy or battery applications to recover from software lockup.
When using the HFINTOSC as the system clock, the oscillator accuracy is approximately +/-2% across temperature and voltage. For UART communications requiring tighter baud-rate accuracy, use the 16 MHz crystal mode (LP/XT/HS) with an external crystal or the PLL block. The ADC achieves full 10-bit resolution only when the source impedance stays below 10 kohm; add a sample-and-hold or op-amp buffer for higher-impedance sensors.
Compliance Information
RoHS compliant per Microchip product page. Lead-free SOIC package. E temperature grade is industrial extended (-40C to +125C) but not AEC-Q100 qualified for automotive - use PIC16F721-E/SO automotive variants for AEC-Q100 designs.
