PIC18F43K20-I/ML - 8-bit PIC XLP MCU 64MHz 8KB Flash QFN-44
MPN: PIC18F43K20-I/ML ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $4.1 | $4.10 |
| 10 | $3.69 | $36.90 |
| 100 | $3.07 | $307.00 |
| 500 | $2.78 | $1,390.00 |
| 1,000 | $2.46 | $2,460.00 |
PIC18F43K20-I/ML Overview
A microcontroller (MCU) is a single-chip computer that integrates a CPU, memory (Flash/RAM/EEPROM), and programmable peripherals on one IC. The PIC18 architecture is an enhanced 8-bit RISC core with a C-compiler-optimized instruction set offering an optional extended instruction set for re-entrant code. MCUs sit between fixed-function logic ICs and full application processors, providing deterministic real-time control for embedded applications including motor control, sensor interfacing, and human-machine interfaces. The XLP nanoWatt tier adds deep-sleep operating modes with currents below 1 uA, suitable for energy-harvesting and IoT endpoints where battery life is critical.
Differentiation: 64 MHz operation enables instruction cycles below 62.5 ns, while 16 MIPS throughput supports real-time signal processing. The 10-bit ADC with auto-acquisition can convert during Sleep to minimize CPU wake events. Two rail-to-rail comparators and a programmable 16-level VREF allow direct sensor interfacing without external op-amps. The QFN-44 8x8 mm package with thermal pad delivers low theta-JA for high-I/O-count designs that would otherwise require larger QFP packages.
Typical applications include consumer appliances, low-cost medical devices, industrial sensor hubs, remote controls, and battery-powered IoT nodes. The wide 1.8V-3.6V operating range simplifies designs powered by 2x AA alkaline cells or single-cell Li-ion batteries.
Design consideration: provide a low-impedance ground return to the QFN thermal pad (EP) and stitch it to the system ground plane with multiple vias to achieve specified thermal performance and reduce ground-loop noise on ADC readings.
This page synthesizes distributor pricing, drop-in QFN-44 alternatives, and practical design notes not consolidated elsewhere.
Drop-in alternatives for PIC18F43K20-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 PIC18F43K20-I/ML (same form factor and footprint) — differing in Package, ADC, Operating Temperature, Communication, MSL Level.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PIC18F43K20-I/PT
✅ Drop-In✓ In Stock
$2.69 / Unit
View Datasheet →PIC18F43K20-E/ML
✅ Drop-In✓ In Stock
$1.38 / Unit
View Datasheet →PIC18F43K20-E/PT
✅ Drop-In✓ In Stock
$2.51 / Unit
View Datasheet →PIC18F43K22-I/ML
✅ Drop-In✓ In Stock
$1.95 / Unit
View Datasheet →PIC18F46K20-I/ML
✅ Drop-In✓ In Stock
$3.52 / Unit
View Datasheet →PIC18F4321-I/ML
✅ Drop-In✓ In Stock
$1.22 / Unit
View Datasheet →PIC18F4331-I/ML
✅ Drop-In✓ In Stock
$5.32 / Unit
View Datasheet →PIC18F43K20-I/ML Maximum Ratings & Electrical Characteristics
| Core Architecture | PIC18 8-bit RISC |
| Family | PIC XLP 18K (nanoWatt XLP) |
| Maximum CPU Frequency | 64 MHz |
| Program Memory (Flash) | 8 KB (4K x 16) |
| RAM | 512 bytes |
| Data EEPROM | 256 bytes |
| I/O Pins | 36 |
| ADC | 10-bit, 14 channels |
| Analog Comparators | 2 (rail-to-rail) |
| Operating Voltage Range | 1.8 V to 3.6 V |
| Temperature Range | -40 C to +85 C (Industrial) |
| Package | 44-pin QFN (8x8 mm) with EP |
| Communication | I2C, SPI, EUSART (RS-232/485) |
| Timers | 1 x 8-bit, 3 x 16-bit |
| Mounting Type | Surface Mount |
| RoHS Status | Compliant |
| Lead-Free | Yes |
PIC18F43K20-I/ML Pin Configuration
| Pin 1 | RA2 — PORTA I/O bit 2 (analog AN2) |
| Pin 2 | RA3 — PORTA I/O bit 3 (analog AN3) |
| Pin 3 | RA4 — PORTA I/O bit 4 (analog AN4, T0CKI) |
| Pin 4 | RA5 — PORTA I/O bit 5 (analog AN5, SS1) |
| Pin 5 | RE0 — PORTE I/O bit 0 (analog AN6) |
| Pin 6 | RE1 — PORTE I/O bit 1 (analog AN7) |
| Pin 7 | RE2 — PORTE I/O bit 2 (analog AN8) |
| Pin 8 | VDD — Positive supply voltage |
| Pin 9 | VSS — Ground |
| Pin 10 | RA7 — PORTA I/O bit 7 (oscillator CLKIN) |
| Pin 11 | RA6 — PORTA I/O bit 6 (oscillator CLKOUT) |
| Pin 12 | RC0 — PORTC I/O bit 0 |
| Pin 13 | RC1 — PORTC I/O bit 1 |
| Pin 14 | RC2 — PORTC I/O bit 2 (CCP1) |
| Pin 15 | RC3 — PORTC I/O bit 3 (SCL1) |
| Pin 16 | RC4 — PORTC I/O bit 4 (SDA1) |
| Pin 17 | RC5 — PORTC I/O bit 5 (SDO1) |
| Pin 18 | RC6 — PORTC I/O bit 6 (TX1/CK1) |
| Pin 19 | RC7 — PORTC I/O bit 7 (RX1/DT1) |
| Pin 20 | VSS — Ground |
| Pin 21 | RD0 — PORTD I/O bit 0 |
| Pin 22 | RD1 — PORTD I/O bit 1 |
| Pin 23 | RD2 — PORTD I/O bit 2 |
| Pin 24 | RD3 — PORTD I/O bit 3 |
| Pin 25 | RD4 — PORTD I/O bit 4 |
| Pin 26 | RD5 — PORTD I/O bit 5 (P1B) |
| Pin 27 | RD6 — PORTD I/O bit 6 (P1C) |
| Pin 28 | RD7 — PORTD I/O bit 7 (P1D) |
| Pin 29 | VSS — Ground |
| Pin 30 | VDD — Positive supply voltage |
| Pin 31 | RB0 — PORTB I/O bit 0 (INT0, FLT0) |
| Pin 32 | RB1 — PORTB I/O bit 1 (INT1) |
| Pin 33 | RB2 — PORTB I/O bit 2 (INT2) |
| Pin 34 | RB3 — PORTB I/O bit 3 (CCP2) |
| Pin 35 | RB4 — PORTB I/O bit 4 (IOC) |
| Pin 36 | RB5 — PORTB I/O bit 5 (IOC, PGM) |
| Pin 37 | RB6 — PORTB I/O bit 6 (PGC, IOC) |
| Pin 38 | RB7 — PORTB I/O bit 7 (PGD, IOC) |
| Pin 39 | RA0 — PORTA I/O bit 0 (analog AN0) |
| Pin 40 | RA1 — PORTA I/O bit 1 (analog AN1) |
| Pin 41 | MCLR — Master Clear (reset, active low); pull-up required |
| Pin 42 | RE3 — PORTE I/O bit 3 (input only) |
| Pin 43 | VDD — Positive supply voltage |
| Pin 44 | VSS — Ground |
Typical Applications
PIC18F43K20-I/ML is suitable for 7 applications: Battery-Powered IoT Sensor Node, Consumer Appliance Control, Industrial Sensor Hub, Medical Handheld Monitor, HVAC Thermostat Controller, Low-Cost USB/HID Peripheral, Energy-Harvesting Wireless Switch.
Battery-Powered IoT Sensor Node
The PIC18F43K20-I/ML is well suited for battery-powered IoT sensor nodes that spend most of their time asleep, waking only to take readings and transmit. Its nanoWatt XLP technology delivers sub-1 uA sleep current at 1.8 V, far below typical Cortex-M0+ deep-sleep figures, while the 10-bit ADC with auto-acquisition can complete conversions during Sleep. The 36 I/O pins interface multiple sensors (temperature, humidity, motion) over SPI/I2C, and the 256-byte EEPROM stores calibration constants without external NVM. The wide 1.8-3.6 V supply range supports direct operation from a 2x AA alkaline or single Li-ion cell. Use it where determinism and 10-year battery life matter more than raw MHz.
Recommended
Consumer Appliance Control
The PIC18F43K20-I/ML supports consumer appliances such as coffee makers, blenders, and small kitchen electronics that need low-cost capacitive-touch sensing, PWM motor control, and a small user interface. Its 5 CCP modules deliver 10-bit PWM at up to 64 MHz for precise motor speed control and LED dimming, while the two rail-to-rail analog comparators enable touch/proximity sensing without dedicated ICs. The 8 KB Flash fits typical appliance control firmware with room to spare for OTA-ready bootloaders. The QFN-44 8x8 mm package keeps board area small, enabling cost-sensitive designs that must compete on retail price points under $50.
Recommended
Industrial Sensor Hub
The PIC18F43K20-I/ML serves as a sensor hub in industrial environments aggregating analog 4-20 mA or 0-10 V signals from multiple field sensors, then forwarding processed data over RS-485 via the EUSART. The 14-channel 10-bit ADC with 1.2 V fixed voltage reference provides ratiometric measurements at typical 4-wire transducer interfaces, while the 36 I/O pins handle discrete limit switches and indicator LEDs. The -40 C to +85 C industrial temperature range suits factory floor operation; the QFN-44 package supports conformal-coated PCBAs. Use it as a local concentrator before forwarding to a PLC over Modbus RTU.
Recommended
Medical Handheld Monitor
The PIC18F43K20-I/ML fits non-critical medical handhelds such as thermometer readers, pulse-oximetry front-ends, and medication-reminder devices where its 14-channel 10-bit ADC digitizes analog sensor outputs at sufficient resolution for the application. The nanoWatt XLP sleep modes extend battery life to weeks of standby, while the 256-byte EEPROM stores user preferences and calibration data that must survive battery removal. The PIC18 instruction set has a decades-long safety history in FDA-cleared devices, easing regulatory submission for Class I/II devices. Note: this part is industrial-grade (-40 to +85 C), so ensure the application's operating range matches.
Recommended
HVAC Thermostat Controller
The PIC18F43K20-I/ML drives HVAC thermostat electronics that require reliable operation across -40 C to +85 C with on-board analog sensor conditioning. The PIC18's five CCP/PWM channels control triac-fired line-voltage relays and variable-speed fan outputs, while the 14-channel ADC reads onboard temperature sensors with software-selectable 1.2 V FVR providing ratiometric measurements unaffected by VDD drift. The 8 KB Flash holds typical thermostat application code plus a bootloader for field firmware updates. The QFN-44 8x8 mm package is small enough to fit within conventional thermostat footprints.
Recommended
Low-Cost USB/HID Peripheral
The PIC18F43K20-I/ML is pin-compatible with USB-equipped PIC18F45K50 family members, enabling a single PCB layout that supports either HID or non-USB variants. For non-USB peripherals like keyboards, mice, custom HID remotes, and game controllers, the 43K20 provides the 64 MHz CPU speed and 8 KB Flash needed for HID report handling plus debounced scanning. The integrated 1.2 V FVR improves ADC-based analog joystick readings, while 36 I/O pins support full-sized mechanical key matrices. Use it as a low-cost companion IC for low-rate USB peripherals.
Recommended
Energy-Harvesting Wireless Switch
The PIC18F43K20-I/ML is well matched for battery-less wireless wall switches that draw micro-currents from kinetic piezo harvesters or RF energy. Its nanoWatt XLP sleep current below 1 uA extends the time between user actuations to charge the storage capacitor, while the 64 MHz wake-and-run speed processes button event detection and sub-GHz packet transmission in under 2 ms. The 256-byte EEPROM stores unique node IDs and pairing keys that must persist across power cycles. Its QFN-44 8x8 mm package fits flush-mount in standard wall-switch enclosures.
Recommended
Recommended Products Summary
Engineering reference data for PIC18F43K20-I/ML — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC18F43K20-I/PT | PIC18F43K20-E/ML | PIC18F43K22-I/ML | PIC18F46K20-I/ML | PIC18F4321-I/ML |
|---|---|---|---|---|---|---|
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Package | 44-pin QFN (ML) 8x8 mm | 44-pin TQFP (PT) 10x10 mm | 44-pin QFN (ML) 8x8 mm - same | 44-pin QFN (ML) - same | 44-pin QFN (ML) - same | 44-pin QFN (ML) - same |
| Flash Memory | 8 KB | 8 KB | 8 KB | 16 KB (+100%) | 64 KB (+700%) | 8 KB |
| RAM | 512 bytes | 512 bytes | 512 bytes | 1280 bytes (+150%) | 3896 bytes (+660%) | 256 bytes (-50%) |
| Maximum Frequency | 64 MHz | 64 MHz | 64 MHz | 64 MHz | 64 MHz | 40 MHz (-37.5%) |
| Temperature Range | -40C to +85C (Industrial) | -40C to +85C | -40C to +125C (Extended) | -40C to +85C | -40C to +85C | -40C to +85C |
| I/O Pins | 36 | 36 | 36 | 36 | 36 | 36 |
| ADC | 10-bit, 14 channels | 10-bit, 14 channels | 10-bit, 14 channels | 10-bit, 14 channels | 10-bit, 14 channels | 10-bit, 13 channels |
Key Differentiators
- Higher memory headroom in identical QFN-44 footprint (vs PIC18F46K20-I/ML)
- Faster CPU than legacy sibling at same cost (vs PIC18F4321-I/ML)
- Same footprint with motor-control extension (vs PIC18F4331-I/ML)
Design Notes
Solder the exposed thermal pad (EP) of the QFN-44 package to a continuous ground copper pour with at least 6 thermal vias connecting to the inner/ground plane. The EP is electrically tied to VSS internally, so a direct PCB thermal bond reduces theta-JA from ~28 C/W (QFN with no EP connection) to ~5 C/W. This matters most when operating the MCU at peak 64 MHz near +85 C ambient; without EP soldering, the silicon can thermally throttle or trigger thermal shutdown at low ambient loads.
Add 100 nF ceramic decoupling close to each VDD pin (pins 8, 30, 43) with traces no longer than 5 mm to minimize parasitic inductance. Place a 10 uF bulk capacitor near the MCU and, if MCLR is used with an external reset supervisor, a 10 kohm pull-up to VDD. Do not route sensitive analog traces (AN0-AN8) under the QFN body where the EP plane injects noise; route them on a separate layer or keep them on the top layer adjacent to the device.
Always configure the CONFIG3H register's MSSPMSKx bits and the CONFIG4L register's XINST bit before enabling peripheral features such as 16-bit instruction mode; mistakes here can brick the part in-circuit. Use Microchip's PICkit 3 or MPLAB ICD 4 with ICSP pins PGC/PGD and MCLR for in-system programming. Note: the MCLR pin must NOT be left floating - a missing pull-up causes unpredictable reset behavior and prevents debugger detection of the device.
The 10-bit ADC is sensitive to digital switching noise. Place ADC analog inputs so they don't share the connector pins or signal traces with high-speed digital lines (CCP, EUSART). Use a low-pass RC filter (1 kohm + 100 nF) on analog inputs longer than 50 mm. Enable the auto-acquisition mode and select ADCON2 acquisition time of at least 16 TAD for 10 kohm-source analog signals.
Compliance Information
RoHS compliant per distributor listings. No AEC-Q100 automotive grade variant exists in this family. Halogen-free status not explicitly stated by Microchip in available sources.
