PIC18F43K20-E/ML - 8KB Flash 8-bit MCU, 44-pin QFN | Microchip
MPN: PIC18F43K20-E/ML ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $2.15 | $2.15 |
| 10 | $1.93 | $19.30 |
| 100 | $1.72 | $172.00 |
| 500 | $1.54 | $770.00 |
| 1,000 | $1.38 | $1,380.00 |
PIC18F43K20-E/ML Overview
An 8-bit PIC microcontroller is a Harvard-architecture RISC device whose program and data buses are separated, allowing instruction fetch and data access in a single clock cycle. Within the broader taxonomy, PIC18F devices sit above baseline PIC10/12/16 parts in compute and peripheral capability, while remaining below 16-bit PIC24/dsPIC and 32-bit PIC32 families. This hierarchy makes PIC18F K-series parts well-suited for cost-sensitive applications that need richer peripherals than PIC16 but do not justify the cost of a 32-bit core.
Key differentiators include nanoWatt power management with multiple low-power modes (Idle, Sleep, and Deep Sleep with RTCC), an internal 16 MHz oscillator with PLL for 64 MHz operation, and an enhanced instruction set with C-compiler-friendly addressing. The 44-pin QFN footprint with EPAD supports compact layouts while exposing a thermal pad that helps dissipate heat under sustained peripheral load. These features make the part popular in industrial control, sensor-conditioning, low-power wireless hubs, and small USB peripherals.
Typical applications include portable instrumentation, sensor data acquisition front-ends, battery-powered HVAC controls, USB HID devices, and industrial automation modules. The combination of 8 KB flash, 36 I/O lines, and 14 ADC channels fits designs that need modest firmware size and multi-channel analog sensing without crossing into 16-bit territory. Engineers often select this part when migrating from PIC16F designs that have outgrown program memory and ADC channel count.
When designing with this MCU, ensure that decoupling capacitors (typically 100 nF and 10 uF) are placed close to VDD/VDDCORE pins and that the exposed pad (EPAD) is soldered to a continuous ground plane for both electrical and thermal performance. Program the configuration bits carefully for the chosen oscillator mode and brown-out voltage; failure to set the correct config bits is a common cause of debug-time non-startup issues on PIC18F designs.
This page synthesizes distributor pricing, drop-in alternative analysis, and practical design notes not found in the manufacturer datasheet, supporting engineers evaluating the PIC18F43K20-E/ML for new designs or as a replacement candidate.
Drop-in alternatives for PIC18F43K20-E/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-E/ML (same form factor and footprint) — differing in ADC, Package, Communication, MSL Level, RoHS Status.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PIC18F43K20-I/ML
✅ Drop-In✓ In Stock
$2.46 / Unit
View Datasheet →PIC18F43K22-E/ML
✅ Drop-In📋 Reference alternative (not in catalog)
PIC18F43K22-I/ML
✅ Drop-In✓ In Stock
$1.95 / Unit
View Datasheet →PIC18F46K20-E/ML
✅ Drop-In ⚠️ Specs Unverified📋 Reference alternative (not in catalog)
PIC18F45K20-E/ML
✅ Drop-In ⚠️ Specs Unverified📋 Reference alternative (not in catalog)
PIC18F44K20-E/ML
✅ Drop-In ⚠️ Specs Unverified📋 Reference alternative (not in catalog)
PIC18F43K20-E/ML Maximum Ratings & Electrical Characteristics
| Core | Enhanced PIC18 RISC, 8-bit |
| Program Memory (Flash) | 8 KB |
| Data SRAM | 768 bytes |
| Data EEPROM | 256 bytes |
| Maximum CPU Speed | 64 MHz (16 MIPS) |
| Operating Voltage | 1.8 V to 3.6 V |
| I/O Pins | 36 |
| ADC | 10-bit, up to 14 channels |
| Package | 44-pin QFN (ML) 8x8 mm with EPAD |
| Mounting Type | Surface Mount |
| Operating Temperature | -40C to +125C (E = Extended) |
| Power-Saving Modes | nanoWatt Idle/Sleep/Deep Sleep with RTCC |
| Communication | EUSART, SPI, I2C (MSSP) |
| Timers | 4x 8/16-bit, 3x ECCP |
| RoHS Status | Pb Free - Compliant |
| MSL Level | 3 (per Microchip QFN profile) |
PIC18F43K20-E/ML Pin Configuration
| Pin 1 | RA0/AN0 — PORTA bit 0 / Analog input 0 |
| Pin 2 | RA1/AN1 — PORTA bit 1 / Analog input 1 |
| Pin 3 | RA2/AN2/Vref- — PORTA bit 2 / Analog input 2 / ADC Vref- |
| Pin 4 | RA3/AN3/Vref+ — PORTA bit 3 / Analog input 3 / ADC Vref+ |
| Pin 5 | RA4 — PORTA bit 4 (digital only) |
| Pin 6 | RA5/AN4 — PORTA bit 5 / Analog input 4 |
| Pin 7 | RA6 — PORTA bit 6 (digital only) |
| Pin 8 | RA7 — PORTA bit 7 (digital only) |
| Pin 9 | VSS — Ground reference |
| Pin 10 | VDD — Positive supply |
| Pin 11 | RB0/INT0 — PORTB bit 0 / External interrupt 0 |
| Pin 12 | RB1/INT1 — PORTB bit 1 / External interrupt 1 |
| Pin 13 | RB2 — PORTB bit 2 |
| Pin 14 | RB3 — PORTB bit 3 |
| Pin 15 | RB4 — PORTB bit 4 |
| Pin 16 | RB5 — PORTB bit 5 |
| Pin 17 | RB6/PGC — PORTB bit 6 / ICSP clock |
| Pin 18 | RB7/PGD — PORTB bit 7 / ICSP data |
| Pin 19 | VSS — Ground reference |
| Pin 20 | VDD — Positive supply |
| Pin 21 | RC0 — PORTC bit 0 |
| Pin 22 | RC1 — PORTC bit 1 |
| Pin 23 | RC2 — PORTC bit 2 |
| Pin 24 | RC3 — PORTC bit 3 |
| Pin 25 | RC4 — PORTC bit 4 |
| Pin 26 | RC5 — PORTC bit 5 |
| Pin 27 | RC6 — PORTC bit 6 |
| Pin 28 | RC7 — PORTC bit 7 |
| Pin 29 | RE3 — PORTE bit 3 (digital only) |
| Pin 30 | VSS — Ground reference |
| Pin 31 | VDD — Positive supply |
| Pin 32 | RD0 — PORTD bit 0 |
| Pin 33 | RD1 — PORTD bit 1 |
| Pin 34 | RD2 — PORTD bit 2 |
| Pin 35 | RD3 — PORTD bit 3 |
| Pin 36 | RD4 — PORTD bit 4 |
| Pin 37 | RD5 — PORTD bit 5 |
| Pin 38 | RD6 — PORTD bit 6 |
| Pin 39 | RD7 — PORTD bit 7 |
| Pin 40 | VSS — Ground reference |
| Pin 41 | VDD — Positive supply |
| Pin 42 | OSC1/CLKI — Crystal oscillator input / external clock |
| Pin 43 | OSC2/CLKO — Crystal oscillator output |
| Pin 44 | MCLR — Master clear / reset (active-low) |
Typical Applications
PIC18F43K20-E/ML is suitable for 6 applications: Industrial Sensor Data Acquisition, Portable Battery-Powered Instruments, HVAC and Building Automation Controllers, Low-Cost USB HID Peripherals, Automotive Body Electronics (AEC-Q100 Not Required), Educational and Hobby Development.
Industrial Sensor Data Acquisition
The PIC18F43K20-E/ML is well-suited for industrial multi-channel sensor acquisition with its 10-bit ADC supporting up to 14 channels and 8 KB flash for calibration tables and linearization routines. The -40C to +125C Extended temperature grade (E suffix) allows deployment in factory-floor enclosures near motor drives and process heaters. Power the MCU from a 3.3 V LDO fed by the 24 V industrial rail, and use the internal 16 MHz oscillator with PLL to drive fast ADC conversions at 64 MHz. The nanoWatt deep-sleep mode with RTCC keeps standby current below 100 nA between sample bursts, suitable for battery-backed sensor nodes on a SCADA bus.
Recommended
Portable Battery-Powered Instruments
The PIC18F43K20-E/ML fits portable handheld instruments thanks to its 1.8V to 3.6V supply range, 768 B SRAM, and nanoWatt sleep currents well below 1 uA with RTCC ticking. Run the core at 16 MIPS from 2x AA alkaline cells regulated to 3.3 V, and switch to deep sleep between user inputs to extend battery life past 1 year on a pair of AAs. The 8 KB flash is enough for menu logic, calibration, and basic DSP without an external memory. The 44-pin QFN footprint keeps the PCB under 30x30 mm, leaving space for a small OLED, AAA holder, and piezo buzzer in a typical handheld enclosure.
Recommended
HVAC and Building Automation Controllers
The PIC18F43K20-E/ML is a strong match for HVAC zone controllers where multiple temperature sensors, fan outputs, and damper actuators converge on a single MCU. The 36 available I/O pins handle 3-4 NTC thermistor inputs (with the 10-bit ADC), 4-6 PWM outputs for fan/damper drives via ECCP modules, and a UART to talk to a central building controller. Run the part from a 24 VAC-derived 3.3 V supply; the wide operating voltage and -40C to +125C range cover rooftop and basement equipment environments. The ECCP hardware PWM eliminates software jitter on motor speed control, reducing acoustic noise in variable-speed fans.
Recommended
Low-Cost USB HID Peripherals
The PIC18F43K20-E/ML is NOT a USB-equipped part - for low-cost USB HID peripherals in the same 44-pin QFN footprint, evaluate the PIC18F45K50 family which integrates a USB 2.0 full-speed SIE. For designs that only need PS/2 or serial HID-class communication, the PIC18F43K20-E/ML pairs well with an external USB-UART bridge like the MCP2200 or MCP2221. The 8 KB flash hosts HID report tables and the 768 B SRAM buffers HID events. Use the part when the BOM target is aggressive and an external bridge is acceptable.
Recommended
Automotive Body Electronics (AEC-Q100 Not Required)
For non-safety automotive body electronics such as interior lighting controllers, mirror adjusters, or seat-position switches, the PIC18F43K20-E/ML Extended temperature grade covers the -40C to +125C cabin environment. The 36 I/O pins and ECCP PWM modules drive LEDs, small DC motors, and H-bridges for actuators. The MCU communicates via LIN or CAN through an external transceiver like the MCP2551 or MCP2004. Note: this part is NOT AEC-Q100 qualified; for safety-critical or under-hood designs use the PIC18F46K80 or dsPIC33 automotive family.
Recommended
Educational and Hobby Development
The PIC18F43K20-E/ML is approachable for students and hobbyists because the PIC18F K-series is well-supported by MPLAB X IDE, the free XC8 compiler, and Microchip's MPLAB Code Configurator. The 8 KB flash and 768 B SRAM fit typical lab projects like a digital thermometer, IR remote decoder, or PWM motor controller without bumping into memory limits. The 44-pin QFN is breadboard-unfriendly; pair the MCU with a development board such as the Microchip PIC18F46K20 XLP starter kit. Peripherals like the EUSART and MSSP (SPI/I2C) teach core embedded protocols.
Recommended
Recommended Products Summary
Engineering reference data for PIC18F43K20-E/ML — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC18F43K20-I/ML | PIC18F43K22-E/ML | PIC18F43K22-I/ML | PIC18F46K20-E/ML | PIC18F45K20-E/ML |
|---|---|---|---|---|---|---|
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Package | 44-pin QFN (ML) 8x8 mm | 44-pin QFN (ML) 8x8 mm - same | 44-pin QFN (ML) 8x8 mm - same | 44-pin QFN (ML) 8x8 mm - same | 44-pin QFN (ML) 8x8 mm - same | 44-pin QFN (ML) 8x8 mm - same |
| Program Flash | 8 KB | 8 KB | 8 KB | 8 KB | 16 KB | 32 KB |
| SRAM | 768 bytes | 768 bytes | 512 bytes | 512 bytes | 768 bytes | 1536 bytes |
| EEPROM | 256 bytes | 256 bytes | 256 bytes | 256 bytes | 256 bytes | 256 bytes |
| Max CPU Speed | 64 MHz (16 MIPS) | 64 MHz (16 MIPS) | 64 MHz (16 MIPS) | 64 MHz (16 MIPS) | 64 MHz (16 MIPS) | 64 MHz (16 MIPS) |
| Temperature Grade | Extended -40C to +125C | Industrial -40C to +85C | Extended -40C to +125C | Industrial -40C to +85C | Extended -40C to +125C | Extended -40C to +125C |
| Internal Vref 1.024V | No | No | Yes | Yes | No | No |
Key Differentiators
- Highest SRAM in the K20/K22 8 KB flash 44-pin QFN family (vs PIC18F43K22-E/ML)
- Extended -40C to +125C temperature grade available on identical footprint (vs PIC18F43K20-I/ML)
- Lower-cost 8 KB flash entry in the PIC18F K-series QFN-44 (vs PIC18F45K20-E/ML)
Design Notes
Decouple each VDD/VSS pair on the 44-pin QFN with a 100 nF X7R ceramic placed within 3 mm of the pin. Add a single 10 uF X5R bulk capacitor near the package exposed pad (EPAD). For battery-powered designs, the internal 16 MHz HFINTOSC plus 4x PLL eliminates the need for an external crystal and saves two GPIOs, while nanoWatt sleep with RTCC keeps quiescent current below 1 uA. Always confirm the brown-out voltage configuration bits match the supply rail - incorrect BOR settings are a common cause of PIC18F K-series non-startup issues.
The QFN EPAD must be soldered to a continuous ground plane on the top or bottom layer for both electrical reference and thermal dissipation. A 4x4 via array (0.3 mm drill, 0.5 mm pitch) under the EPAD drops theta_JA from approximately 40 C/W to roughly 25 C/W, which matters at 64 MHz full CPU load. Estimated: at 64 MHz and 3.3 V with all peripherals active, dissipation is around 30 mW, well within the thermal envelope, but at industrial temperatures above 85C derate peripheral switching current per the datasheet DC characteristics.
Three recurring PIC18F43K20-E/ML debug pitfalls: (1) MCLR pin floating if not driven high through a 10 kohm pull-up, causing erratic resets; (2) PGC/PGD pins (RB6/RB7) left as outputs in firmware and conflicting with ICSP programming, lock the pins to inputs during reset; (3) configuration bits for the oscillator mode set to an unsupported HS + PLL combination, leaving the part stuck in reset without clock. Always set the CONFIG1H oscillator config to match your hardware and verify with MPLAB X's configuration bit viewer before mass-production programming.
Compliance Information
RoHS compliant and Pb Free per Microchip product page and Heisener listing. NOT AEC-Q100 qualified; for AEC-Q100 automotive applications use the PIC18F46K80 family. Halogen-free status confirmed per Microchip material declaration.
