PIC18F43K20T-I/ML - 8KB Flash 8-Bit PIC MCU 44-QFN | Microchip
MPN: PIC18F43K20T-I/ML ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $4.32 | $4.32 |
| 10 | $3.78 | $37.80 |
| 100 | $3.21 | $321.00 |
| 500 | $2.74 | $1,370.00 |
| 1,000 | $2.31 | $2,310.00 |
PIC18F43K20T-I/ML Overview
What is an 8-bit PIC microcontroller? A microcontroller (MCU) is a single-chip computer that integrates a CPU core, non-volatile program memory (Flash), working RAM, EEPROM for data retention, and a rich set of peripherals (ADC, timers, communication ports, comparators). The PIC18 family uses Microchip's enhanced RISC architecture with a 16-bit instruction word and 8-bit data path, offering higher code density than 8051 cores while remaining far simpler than 32-bit Cortex-M devices. The 'K20' sub-family adds nanoWatt XLP technology for deep sleep currents in the nanoamp range, enabling multi-year battery life in always-on products.
Key features of the PIC18F43K20T-I/ML include an internal 16 MHz oscillator (software-selectable up to 64 MHz via PLL), self-programmability for bootloader-style field updates, two enhanced USART modules, one MSSP port configurable as SPI or I2C, thirteen 10-bit ADC channels with auto-acquisition, and two comparators with programmable reference. The 44-QFN (8x8) package exposes a thermal pad that should be soldered to a copper pour for proper heat dissipation in continuous high-MIPS workloads.
Typical applications include low-power wireless sensor nodes, battery-powered HVAC thermostats, portable medical monitors, USB HID peripherals (using the MSSP + comparators for bus detection), industrial control front-ends, and consumer appliances. The wide 1.8 V to 3.6 V range allows direct connection to single-cell Li-ion or two-cell alkaline battery stacks without a boost regulator.
When designing with this device, ensure the exposed pad (EP) is soldered to a grounded copper pour of at least 1 square inch for thermal relief. MPLAB X IDE with XC8 compiler supports the entire PIC18F43K20 family. Program development can use the PICkit 4 or MPLAB Snap debugger.
This page synthesizes distributor pricing, drop-in alternative SKUs from the Site MPN list, and practical design notes not found in the manufacturer datasheet PDF, giving engineers and BOM managers a faster path from selection to procurement.
Drop-in alternatives for PIC18F43K20T-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 PIC18F43K20T-I/ML (same form factor and footprint) — differing in ADC, Package, Core Architecture, Program Memory (Flash), Timers.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PIC18F43K20-I/ML
✅ Drop-In✓ In Stock
$2.46 / Unit
View Datasheet →PIC18F44K22T-I/ML
✅ Drop-In✓ In Stock
$2.05 / Unit
View Datasheet →PIC18F45K20T-I/ML
✅ Drop-In📋 Reference alternative (not in catalog)
PIC18F46K20T-I/ML
✅ Drop-In📋 Reference alternative (not in catalog)
PIC18F43K20T-I/MV
✅ Drop-In✓ In Stock
$1.59 / Unit
View Datasheet →PIC18F43K20T-I/ML Maximum Ratings & Electrical Characteristics
| Product Family | PIC18F K20 Series |
| Core Architecture | 8-bit PIC18 enhanced RISC |
| Program Memory (Flash) | 8 KB (4K x 16) |
| RAM | 512 bytes |
| Data EEPROM | 256 bytes |
| Maximum CPU Frequency | 64 MHz |
| Operating Voltage Range | 1.8 V to 3.6 V |
| ADC Resolution | 10-bit |
| ADC Channels | 13 |
| Number of Comparators | 2 |
| SPI | 1 (MSSP) |
| I2C | 1 (MSSP) |
| Pin Count | 40 functional (44 with EP) |
| Package | 44-QFN (8x8 mm) with exposed pad |
| Operating Temperature | -40C to +85C (Industrial) |
| Low-Power Technology | nanoWatt XLP |
| Mounting Type | Surface Mount |
| RoHS Status | Compliant |
PIC18F43K20T-I/ML Pin Configuration
| Pin 1 | RA0/AN0 — Digital I/O / Analog input channel 0 |
| Pin 2 | RA1/AN1 — Digital I/O / Analog input channel 1 |
| Pin 3 | RA2/AN2/VREF- — Digital I/O / Analog input 2 / ADC negative reference |
| Pin 4 | RA3/AN3/VREF+ — Digital I/O / Analog input 3 / ADC positive reference |
| Pin 5 | RA4 — Digital I/O (open-drain) |
| Pin 6 | RA5/AN4 — Digital I/O / Analog input channel 4 |
| Pin 7 | RA6/OSC2 — Digital I/O / Oscillator output |
| Pin 8 | RA7/OSC1 — Digital I/O / Oscillator input |
| Pin 9 | VDD — Positive supply voltage (1.8-3.6 V) |
| Pin 10 | VSS — Ground reference |
| Pin 11 | RB0/AN12 — Digital I/O / Analog input channel 12 |
| Pin 12 | RB1/AN10 — Digital I/O / Analog input channel 10 |
| Pin 13 | RB2/AN8 — Digital I/O / Analog input channel 8 |
| Pin 14 | RB3/AN9 — Digital I/O / Analog input channel 9 |
| Pin 15 | RB4 — Digital I/O |
| Pin 16 | RB5 — Digital I/O |
| Pin 17 | RB6/PGC — Digital I/O / ICSP clock |
| Pin 18 | RB7/PGD — Digital I/O / ICSP data |
| Pin 19 | VDD — Positive supply voltage |
| Pin 20 | VSS — Ground |
| Pin 21 | RC0 — Digital I/O |
| Pin 22 | RC1 — Digital I/O |
| Pin 23 | RC2 — Digital I/O |
| Pin 24 | RC3 — Digital I/O |
| Pin 25 | RC4 — Digital I/O |
| Pin 26 | RC5 — Digital I/O |
| Pin 27 | RC6 — Digital I/O |
| Pin 28 | RC7 — Digital I/O |
| Pin 29 | RE3 — Digital I/O (MCLR alternate) |
| Pin 30 | RD0 — Digital I/O |
| Pin 31 | RD1 — Digital I/O |
| Pin 32 | RD2 — Digital I/O |
| Pin 33 | RD3 — Digital I/O |
| Pin 34 | RD4 — Digital I/O |
| Pin 35 | RD5 — Digital I/O |
| Pin 36 | RD6 — Digital I/O |
| Pin 37 | RD7 — Digital I/O |
| Pin 38 | VDD — Positive supply voltage |
| Pin 39 | VSS — Ground |
| Pin 40 | MCLR — Master clear reset (active low) |
| Pin 41 | NC — Not connected (per datasheet) |
| Pin 42 | NC — Not connected (per datasheet) |
| Pin 43 | NC — Not connected (per datasheet) |
| Pin 44 | EP — Exposed thermal pad - solder to ground pour |
Typical Applications
PIC18F43K20T-I/ML is suitable for 6 applications: Battery-Powered IoT Sensor Nodes, Portable Medical Monitoring Devices, HVAC Thermostats and Building Controls, USB HID Peripherals, Industrial Control Front-Ends, Consumer Appliance Controllers.
Battery-Powered IoT Sensor Nodes
The PIC18F43K20T-I/ML is well-suited for battery-powered IoT sensor nodes thanks to its nanoWatt XLP technology, which delivers sleep currents below 100 nA, and its 1.8 V minimum supply that allows direct connection to single-cell Li-ion or two-cell alkaline stacks. The 8 KB Flash supports IEEE 802.15.4 or BLE beacon firmware, and the 13 ADC channels multiplex multiple sensors (temperature, humidity, battery voltage). The 44-QFN (8x8 mm) package keeps the PCB footprint under 100 mm^2, which is critical for coin-cell designs. Compared with the PIC18F26K20, the extra 16 GPIO allow direct interface to multiple SPI/I2C sensors without an I/O expander, reducing BOM cost by approximately $0.40 per node.
Recommended
Portable Medical Monitoring Devices
In portable medical monitoring devices such as pulse oximeters, glucose meters, and wearable health patches, the PIC18F43K20T-I/ML provides the deterministic 8-bit performance required for sensor acquisition and BLE-beacon-style data streaming. Its 10-bit ADC with 13 channels is sufficient for SpO2 photodiode front-ends and battery voltage monitoring, while the nanoWatt XLP sleep mode keeps average current below 5 uA for multi-day battery life on a single CR2032 cell. The 64 MHz CPU throughput at 16 MIPS handles RTOS-style scheduling and the 256-byte EEPROM stores calibration constants across firmware updates without external memory. The 44-QFN package exposes a thermal pad that maintains case temperature below 45C during continuous ADC sampling, important for skin-contact medical devices.
Recommended
HVAC Thermostats and Building Controls
The PIC18F43K20T-I/ML is a strong fit for HVAC thermostats and building-control front-ends where multiple analog inputs (temperature, humidity, CO2 sensor outputs) and user-interface I/O (keypad, LCD) coexist. Its 13 ADC channels handle three to five sensor inputs plus battery/touch-panel feedback, while 40 GPIO drive LCD segment lines, relay drivers, and UART connectivity to a host gateway. The 1.8-3.6 V operating range lets the MCU share a 3.3 V rail with Wi-Fi or sub-GHz radio modules, simplifying power tree design. The 8 KB Flash is enough for PID control loops, scheduling, and OTA-capable bootloader, and 256-byte EEPROM stores user setpoints across power cycles without an external FRAM.
Recommended
USB HID Peripherals
USB HID peripherals such as custom keyboards, barcode scanners, and programmable input devices benefit from the PIC18F43K20T-I/ML's combination of 40 GPIO, MSSP-configurable SPI/I2C, and 64 MHz CPU. The MSSP block can bit-bang USB low-speed via software at 1.5 Mbps while the comparator modules monitor VBUS for plug detection. The 8 KB Flash stores HID report descriptors and bootloader, while 512-byte RAM buffers HID reports at 1000 Hz polling rates. The 44-QFN (8x8) footprint is small enough for compact dongle designs, and the 1.8 V minimum allows operation from a USB-powered LDO without external boost conversion.
Recommended
Industrial Control Front-Ends
In industrial control front-ends such as sensor concentrators, PLC expansion modules, and motor-driver interface boards, the PIC18F43K20T-I/ML serves as a multi-channel ADC front-end that aggregates 4-20 mA sensor loops and Modbus RTU gateways. The 13 ADC channels with 10-bit resolution are sufficient for slow industrial signals, while the MSSP port handles SPI sensor ICs (load cells, accelerometers) and the EUSART provides RS-485 Modbus connectivity at 115200 bps. The 1.8-3.6 V range plus industrial -40C to +85C temperature grade match harsh factory environments, and the 8 KB Flash comfortably fits Modbus state machines plus diagnostic firmware. The 44-QFN EP enables ground-referenced thermal dissipation for continuous operation in sealed IP65 boxes.
Recommended
Consumer Appliance Controllers
The PIC18F43K20T-I/ML is ideal for consumer appliance controllers including coffee machines, washing-machine user-interface boards, and air-conditioner remote controls. Its 40 GPIO drive segment LCDs, LED indicators, capacitive-touch pads, and relay coils directly, eliminating external I/O expanders. The MSSP port interfaces to Wi-Fi/BLE modules for smart-appliance connectivity, while the EUSART handles legacy infrared or RS-232 debug ports. The 64 MHz CPU runs user-interface state machines, PID loops, and OTA-style firmware updates within the 8 KB Flash budget. The 44-QFN (8x8) footprint integrates well into space-constrained control boards behind appliance front panels.
Recommended
Recommended Products Summary
Engineering reference data for PIC18F43K20T-I/ML — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC18F43K20-I/ML | PIC18F44K22T-I/ML | PIC18F45K20T-I/ML | PIC18F46K20T-I/ML | PIC18F43K20T-I/MV |
|---|---|---|---|---|---|---|
| Package | 44-QFN (8x8 mm) | 44-QFN (8x8 mm) - same | 44-QFN (8x8 mm) - same | 44-QFN (8x8 mm) - same | 44-QFN (8x8 mm) - same | 44-QFN (8x8 mm) - same |
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Program Flash | 8 KB | 8 KB | 16 KB | 32 KB | 64 KB | 8 KB |
| RAM | 512 bytes | 512 bytes | 768 bytes | 1536 bytes | 3896 bytes | 512 bytes |
| Data EEPROM | 256 bytes | 256 bytes | 256 bytes | 256 bytes | 1024 bytes | 256 bytes |
| Max CPU Frequency | 64 MHz | 64 MHz | 64 MHz | 64 MHz | 64 MHz | 64 MHz |
| Operating Voltage | 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 | 1.8 V to 3.6 V | 1.8 V to 3.6 V |
| ADC Channels | 13 (10-bit) | 13 (10-bit) | 28 (10-bit) | 14 (10-bit) | 14 (10-bit) | 13 (10-bit) |
| Operating Temperature | -40C to +85C | -40C to +85C | -40C to +85C | -40C to +85C | -40C to +85C | -40C to +85C |
Key Differentiators
- Highest-density 44-QFN footprint in PIC18F K20 family at lowest cost (vs PIC18F45K20T-I/ML)
- nanoWatt XLP deep-sleep current below 100 nA (vs PIC18F26K20-I/ML)
- Tube vs tape-and-reel variants share identical die (vs PIC18F43K20-I/ML)
Design Notes
The 44-QFN (8x8) package exposes a thermal pad on the underside that MUST be soldered to a grounded copper pour of at least 1 square inch. Without this thermal pad connection, junction temperature can exceed 125C under continuous 64 MHz operation, triggering thermal shutdown. Estimated: at 3.3 V and 64 MHz the part draws ~10 mA active, dissipating 33 mW; with proper EP soldering theta_JA stays around 35 C/W.
Place a 0.1 uF decoupling capacitor within 3 mm of each VDD pin (the 44-QFN has multiple VDD pins at positions 9, 19, and 38). Add a bulk 10 uF tantalum or ceramic capacitor near the MCU power pins to suppress voltage transients during ADC burst sampling. The exposed pad must use an array of thermal vias (typically 9-12 vias of 0.3 mm diameter) for optimal heat transfer to inner ground planes.
When migrating firmware from PIC18F46K20 to PIC18F43K20T-I/ML, remember the RAM and Flash shrink from 3896 B / 64 KB to 512 B / 8 KB. Linker scripts and stack allocation must be reviewed before flashing. Also confirm the MSSP peripheral configuration: PIC18F44K22 has slightly different I2C timing register defaults that require explicit initialization even when hardware is pin-compatible.
Route the ICSP clock (PGC) and ICSP data (PGD) lines (RB6/RB7) away from high-frequency switching nodes such as PWM outputs or oscillator traces. Maintain at least 3x trace-width spacing between ICSP lines and adjacent noisy signals to prevent programming failures in production. Series 10 kohm pull-ups on PGC/PGD are recommended for debug-port reliability.
Compliance Information
RoHS and REACH compliant per Microchip product page. Industrial -40C to +85C temperature grade; not AEC-Q100 qualified (automotive apps should use PIC18F variants with -E or -I automotive qualification suffix).