PIC16LF721T-I/ML - 8-Bit 16MHz 7KB Flash MCU 20-QFN | Microchip
MPN: PIC16LF721T-I/ML ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $1.62 | $1.62 |
| 10 | $1.49 | $14.90 |
| 100 | $1.28 | $128.00 |
| 500 | $1.1 | $550.00 |
| 1,000 | $0.95 | $950.00 |
| 3,000 | $0.78 | $2,340.00 |
PIC16LF721T-I/ML Overview
An 8-bit microcontroller (MCU) is a programmable logic device that executes one byte-wide instruction per clock, combining a CPU core, non-volatile program memory (Flash), volatile data memory (RAM), and configurable peripherals on a single silicon die. Within the semiconductor taxonomy, an MCU belongs to the integrated circuit family and is a sub-class of microcomputer; the PIC16 mid-range core sits under the Microchip PIC® brand hierarchy, offering 35 single-word instructions and a deterministic Harvard bus. By collapsing CPU, memory and peripherals into one package, MCUs shrink BOM cost, simplify PCB layout, and enable firmware-driven functionality that discrete TTL/CMOS logic cannot match.
Key features include wide operating voltage from 1.8V to 3.6V (extended down to 2.3V for full-speed operation), on-chip 16 MHz internal oscillator with PLL support, nanoWatt XLP™ extreme-low-power technology, integrated 7KB Flash with self-programmability, and broad digital and analog peripheral integration. The 20-QFN (4x4) footprint measures only 4mm x 4mm, making it one of the smallest packages in the PIC16 mid-range line - ideal for size-constrained designs while still giving access to 18 I/O pins.
Internally, the device uses a Harvard architecture with separate program and data buses, a hardware multiplier and an ALU optimized for byte-wide operations. The 'LF' prefix denotes the low-voltage / low-power variant - the die process is trimmed for lower VDD operation and lower active current versus the standard 'F' part, and the nanoWatt XLP technology adds sleep currents measured in nanoamperes, allowing years of battery life on a single coin cell.
Typical applications include battery-powered sensor nodes, remote control transmitters, low-power IoT end nodes, white-goods and small appliance user-interface boards, LED lighting controllers, and consumer toys. Engineers typically select the PIC16LF721 when the design needs more than 14 pins, sub-3.3V operation, and at least 7KB of code space.
When designing with this device, ensure the decoupling capacitor is placed within 5 mm of the VDD pin and that the exposed thermal pad is soldered to the ground pour for proper thermal and electrical performance. The PIC16LF721 is in-system programmable via ICSP, so ensure the PGC/PGD pins are accessible on the PCB for production programming.
This page synthesizes distributor pricing, drop-in alternatives inside the same PIC16 family, and practical design notes not gathered together in the manufacturer datasheet alone.
Drop-in alternatives for PIC16LF721T-I/ML — 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 PIC16LF721T-I/ML (same form factor and footprint) — differing in Core Architecture, Package, Program Memory (Flash), Mounting Type, RoHS Status.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PIC16LF721-I/ML
✅ Drop-In📋 Reference alternative (not in catalog)
PIC16LF726T-I/ML
✅ Drop-In✓ In Stock
$1.49 / Unit
View Datasheet →PIC16LF720T-I/ML
✅ Drop-In✓ In Stock
$0.78 / Unit
View Datasheet →PIC16F721T-I/ML
✅ Drop-In ⚠️ Specs Unverified✓ In Stock
$1.18 / Unit
View Datasheet →PIC16LF1939T-I/ML
✅ Drop-In ⚠️ Specs Unverified✓ In Stock
$2.62 / Unit
View Datasheet →PIC16LF707T-I/ML
✅ Drop-In ⚠️ Specs Unverified✓ In Stock
$1.72 / Unit
View Datasheet →PIC16LF721T-I/ML Maximum Ratings & Electrical Characteristics
| Core Architecture | PIC16 8-bit RISC (Harvard) |
| Program Memory (Flash) | 7 KB (4K x 14 words) |
| Data SRAM | 256 bytes |
| Maximum CPU Speed | 16 MHz (internal oscillator) |
| Instruction Set | 35 single-word instructions |
| Operating Voltage Range | 1.8 V to 3.6 V |
| Full-Speed VDD Minimum | 2.3 V |
| I/O Pins | 18 |
| Package | 20-QFN (4x4 mm) |
| Operating Temperature Range | -40 C to +85 C (Industrial) |
| Low-Power Technology | nanoWatt XLP |
| Mounting Type | Surface Mount |
| RoHS Status | Compliant |
| Lead Finish | Lead-free |
| ICSP Programming | Yes (PGC/PGD) |
| Family | PIC16 LF (mid-range, low-voltage) |
PIC16LF721T-I/ML Pin Configuration
| Pin 1 | RA0/AN0 — Bidirectional I/O / analog channel 0 |
| Pin 2 | RA1/AN1 — Bidirectional I/O / analog channel 1 |
| Pin 3 | RA2/AN2 — Bidirectional I/O / analog channel 2 |
| Pin 4 | RA3/AN3 — Bidirectional I/O / analog channel 3 |
| Pin 5 | RA4/AN4 — Bidirectional I/O / analog channel 4 |
| Pin 6 | RA5/AN5 — Bidirectional I/O / analog channel 5 |
| Pin 7 | VSS — Ground reference |
| Pin 8 | RA7/OSC1 — Bidirectional I/O / crystal oscillator input |
| Pin 9 | RA6/OSC2 — Bidirectional I/O / crystal oscillator output |
| Pin 10 | RC0 — Bidirectional I/O |
| Pin 11 | RC1 — Bidirectional I/O |
| Pin 12 | RC2 — Bidirectional I/O |
| Pin 13 | RC3 — Bidirectional I/O |
| Pin 14 | RC4 — Bidirectional I/O |
| Pin 15 | RC5 — Bidirectional I/O |
| Pin 16 | RC6 — Bidirectional I/O |
| Pin 17 | RC7 — Bidirectional I/O |
| Pin 18 | RB4 — Bidirectional I/O / interrupt-on-change |
| Pin 19 | RB5 — Bidirectional I/O / interrupt-on-change |
| Pin 20 | VDD — Positive supply (1.8V to 3.6V) |
Typical Applications
PIC16LF721T-I/ML is suitable for 6 applications: Battery-Powered Wireless Sensor Node, Consumer Remote Control Transmitter, Low-Power IoT End-Node Actuator, White-Goods and Small Appliance Control Board, LED Lighting Controller, Industrial Sensor Conditioning Module.
Battery-Powered Wireless Sensor Node
The PIC16LF721T-I/ML is well-suited for battery-powered wireless sensor nodes thanks to its 1.8V-3.6V wide supply range and nanoWatt XLP extreme-low-power technology, which delivers sleep currents in the nanoampere range. Placed between a coin-cell battery and a low-power RF module or sensor front-end, the MCU can run duty-cycled sampling and only wake the radio when readings are needed - critical for multi-year battery life on a single CR2032 cell. The 16 MHz core and 256-byte SRAM provide headroom for sensor-fusion routines, while 7 KB Flash accommodates 802.15.4/LoRa driver stacks and over-the-air update logic. Compared with a discrete 8-bit logic implementation, the LF721 collapses the entire control task into one 4x4 mm device.
Recommended
Consumer Remote Control Transmitter
The PIC16LF721T-I/ML fits infrared or RF remote-control transmitters where 18 GPIO pins drive keyboard matrices and LED indicators. Its 16 MHz instruction cycle gives sub-microsecond debounce and IR carrier generation without external timer ICs, while the wide supply range allows direct connection to 2xAAA cells without a boost regulator. The 7 KB Flash supports OEM menu encoding libraries, and ICSP allows end-of-line firmware personalization. Engineers pick the LF721 over the PIC16LF628 because of its higher Flash headroom for advanced IR protocols (RC5, SIRC) and Wake-on-Change interrupt-driven sleep modes for battery preservation.
Recommended
Low-Power IoT End-Node Actuator
For low-power IoT edge nodes driving relays or MOSFETs, the PIC16LF721T-I/ML offers 18 GPIO with 25 mA source/sink capable of directly sinking small relay coils - removing an external driver stage. Its 1.8V-3.6V supply range supports lithium primary cells and energy-harvesting buffers, while the nanoWatt XLP sleep mode drops the active current to single-digit microamps. The 256-byte SRAM is sufficient for queued event buffers; 7 KB Flash accommodates Modbus or Zigbee cluster endpoints. The 20-QFN-4x4 footprint fits inside sealed sensor housings where every square millimeter counts.
Recommended
White-Goods and Small Appliance Control Board
The PIC16LF721T-I/ML is commonly deployed in white-goods control boards like coffee makers, blenders, humidifiers and induction cookers where 8-bit control and 18 digital I/O are sufficient. Its industrial temperature grade (-40 C to +85 C) handles under-cabinet heat, and the LF low-voltage operation tolerates rectified mains step-down without a full regulator. The on-chip ADC reads temperature or current sense for closed-loop control, while timers generate PWM for triac-driven heater elements. Compared with a basic PIC10F, the LF721 supports firmware updates via ICSP without an external bootloader circuit.
Recommended
LED Lighting Controller
The PIC16LF721T-I/ML suits LED lighting controllers where 16 MHz PWM resolution drives RGB strips or tunable-white arrays. The 18 GPIO generates multiple PWM channels without external timer ICs, while the LF low-voltage supply enables direct operation from 12V step-down to 3.3V linear post-regulator chains. NanoWatt XLP sleep modes are critical for battery-powered decorative LED strings, dropping current consumption to microamps between user interactions. Compared with simpler 8-pin PICs, the LF721's 7 KB Flash supports DMX-512 or DALI protocol libraries and scene presets.
Recommended
Industrial Sensor Conditioning Module
In industrial sensor-conditioning modules, the PIC16LF721T-I/ML provides an on-chip ADC for analog sensor signal chains, timers for PWM excitation, and 18 GPIO for digital I/O interfacing with field wiring. The wide 1.8V-3.6V supply permits use in 24V-bus systems with simple linear post-regulation, and the industrial temperature grade supports factory-floor deployment. The 7 KB Flash holds calibration and linearization firmware, while ICSP enables field recalibration - critical for 4-20 mA transducer modules where field replacement is expensive.
Recommended
Recommended Products Summary
Engineering reference data for PIC16LF721T-I/ML — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC16LF721-I/ML | PIC16LF726T-I/ML | PIC16LF720T-I/ML |
|---|---|---|---|---|
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Package | 20-QFN (4x4 mm) | 20-QFN (4x4 mm) - same | 20-QFN (4x4 mm) - same | 20-QFN (4x4 mm) - same |
| SRAM | 256 B | 256 B | Larger | Similar |
| Maximum CPU Speed | 16 MHz | 16 MHz | 20 MHz | 16 MHz |
| Supply Voltage Range | 1.8 V to 3.6 V | 1.8 V to 3.6 V | 1.8 V to 3.6 V | 1.8 V to 3.6 V |
| I/O Pins | 18 | 18 | 18 | 18 |
| Operating Temperature | -40 C to +85 C | -40 C to +85 C | -40 C to +85 C | -40 C to +85 C |
| Low-Power Technology | nanoWatt XLP | nanoWatt XLP | nanoWatt XLP | nanoWatt XLP |
| Packaging | Tape & Reel | Tube | Tape & Reel | Tape & Reel |
Key Differentiators
- Wide 1.8V-3.6V supply range with nanoWatt XLP low-power technology (vs PIC16F721T-I/ML)
- 20-QFN (4x4) exposed-pad package - smallest in PIC16 mid-range family (vs PIC16LF721T-I/SP (SPDIP-20))
- Tape-and-reel packaging for high-volume SMT production (vs PIC16LF721-I/ML (tube))
- Industry-standard PIC16 mid-range core with 35 single-word instructions (vs PIC10F or PIC12F smaller MCUs)
Design Notes
Place a 0.1 uF ceramic decoupling capacitor as close as possible (within 5 mm) to the VDD pin, and pair it with a 10 uF bulk capacitor on the same node. The PIC16LF721T-I/ML's nanoWatt XLP technology achieves sub-microamp sleep current only when VDD is well decoupled - noisy supplies cause leakage in low-power modes. For battery applications, use Schottky diodes or P-FET power switches to disconnect the LDO from the battery during long sleep intervals, reducing quiescent current consumption by orders of magnitude.
The 20-QFN (4x4 mm) exposed thermal pad must be soldered to a continuous ground pour on the top layer, with at least 4 thermal vias connecting to the inner ground plane. The QFN's lead-less design relies on the exposed pad for both electrical ground return and thermal dissipation; failing to solder the pad typically increases theta_JA by 40-60 C/W. Estimated: at 25 mA/GPIO toggle and 16 MHz active, total die power dissipation is roughly 10-15 mW, well below thermal limits, but the exposed pad remains mandatory for production reliability.
Route ICSP signals PGC and PGD away from switching power and high-frequency clock traces to avoid programming noise coupling into the in-circuit serial programming pins. Keep the ICSP connector on production PCBs accessible even in production fixtures - test pads under other components should be avoided. The 'ML' suffix variant in 4x4 QFN requires non-solder-mask-defined (NSMD) land pads for production manufacturing - see Microchip's package footprint recommendation in App-NB-039.
Do not assume 7 KB Flash directly equals 7 KB of C code - the PIC16's 14-bit instruction width means user code is typically 15-30% smaller than the same logic compiled for an 8-bit AVR or 8051. Typical C compilers (XC8 in free or PRO mode) introduce library overhead that consumes 1-2 KB even for blink-style programs. Plan for 4-5 KB of usable C code space when designing firmware; if your project is approaching 6 KB, choose the PIC16LF726T-I/ML drop-in upgrade to gain Flash headroom.
Compliance Information
RoHS compliant per Microchip product page. Industrial temperature grade -40 C to +85 C only; not AEC-Q100 qualified. For automotive, choose Q1 suffix variants.
