PIC18F43K20-I/P - 8KB Flash 8-bit MCU, 64MHz, 40-PDIP | Microchip
MPN: PIC18F43K20-I/P ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $3.45 | $3.45 |
| 10 | $3.1 | $31.00 |
| 100 | $2.65 | $265.00 |
| 500 | $2.2 | $1,100.00 |
| 1,000 | $1.95 | $1,950.00 |
PIC18F43K20-I/P Overview
An 8-bit PIC microcontroller is a CISC Harvard-architecture device that executes one instruction per clock cycle from a wide instruction set including hardware multiply, bit-oriented operations, and direct addressing. Within Microchip's taxonomy, the PIC18 family sits between the PIC16 baseline (12-bit instructions) and PIC24/dsPIC (16-bit) families, offering enhanced peripherals (10-bit ADC, PWM, EUSART, MSSP SPI/I2C) at low cost. The "K20" sub-family emphasizes nanoWatt XLP extreme-low-power technology for battery applications, while the "43K20" pin-count code indicates the 40/44-pin variant.
Key features include 64MHz max CPU speed, 8KB Flash program memory with self-programmability, 512 bytes SRAM, 256 bytes EEPROM, a 14-channel 10-bit ADC with 1.2V fixed voltage reference, two analog comparators with rail-to-rail inputs, two CCP/ECCP modules for PWM/Signal Measurement, and four interrupt-on-change I/O expanders. Communication interfaces include EUSART with LIN support, MSSP for SPI/I2C master/slave, and an enhanced PWM with complementary outputs and dead-band control. The device also integrates a 16-bit timer with gate control, four 8-bit timers, hardware RTCC with calendar, and a programmable LVD/BOR.
Typical applications span consumer electronics (washing machine controllers, microwave ovens, coffee machines), industrial automation (sensor nodes, motor control, HVAC), USB/embedded HID peripherals, smart energy metering, automotive body modules (CAN-less nodes), and battery-powered IoT sensor platforms. Its nanoWatt XLP sleep currents (<100 nA typical) extend coin-cell life in remote sensor nodes. The 40-PDIP package supports breadboard and through-hole prototyping as well as hand-soldered retrofit of legacy through-hole designs without surface-mount reflow infrastructure.
When designing with this part, verify the supply voltage range (1.8V-5.5V) matches your rail, ensure decoupling capacitance (0.1uF + 10uF bulk) is placed within 5mm of VDD pins, and use Microchip's MPLAB X IDE + XC8 compiler for code development. The PIC18F43K20-I/P runs code compatible with PIC18F45K20 (different pin count), PIC18F24K30I (lower pin count), and PIC18F26K20I siblings for portable firmware across packages.
This page synthesizes distributor pricing, drop-in DIP-40 alternatives (PIC18F45K22-I/P, PIC18F4320-I/P), cross-brand considerations, and practical design notes not found in the manufacturer datasheet - supporting both new design and legacy retrofit workflows.
Drop-in alternatives for PIC18F43K20-I/P — 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/P (same form factor and footprint) — differing in Package, Operating Temperature, ADC, Core, MSL Level.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PIC18F45K20-I/P
✅ Drop-In✓ In Stock
$2.45 / Unit
View Datasheet →PIC18F45K22-I/P
✅ Drop-In✓ In Stock
$2.1 / Unit
View Datasheet →PIC18F4321-I/ML
✅ Drop-In✓ In Stock
$1.22 / Unit
View Datasheet →PIC18F4320-I/P
✅ Drop-In✓ In Stock
$4.05 / Unit
View Datasheet →PIC18F4221-I/P
✅ Drop-In✓ In Stock
$3.15 / Unit
View Datasheet →PIC18F4331-I/PT
✅ Drop-In✓ In Stock
$3.05 / Unit
View Datasheet →PIC18F43K20-I/P Maximum Ratings & Electrical Characteristics
| Core Processor | PIC |
| Core Size | 8-bit |
| Series | PIC XLP 18K |
| Program Memory Size | 8 KB (4K x 16) |
| Program Memory Type | FLASH |
| EEPROM Size | 256 x 8 |
| RAM Size | 512 x 8 |
| Maximum Clock Speed | 64 MHz |
| Supply Voltage Range | 1.8 V to 5.5 V |
| Number of I/O Pins | 36 |
| ADC | 10-bit, 14-channel |
| Analog Comparators | 2 (rail-to-rail) |
| PWM Channels | ECCP + CCP modules |
| Communication Interfaces | EUSART, SPI, I2C (MSSP) |
| Package | 40-pin PDIP (0.600 inch, 15.24 mm) |
| Mounting Type | Through-Hole |
| Operating Temperature | -40 C to +85 C (Industrial -I) |
| Low-Power Technology | nanoWatt XLP (<100 nA sleep) |
| RoHS Status | Compliant |
| Lead-Free | Yes |
PIC18F43K20-I/P Pin Configuration
| Pin 1 | RA0/AN0/CVREF — Bidirectional I/O, analog input 0, comparator reference output |
| Pin 2 | RA1/AN1 — Bidirectional I/O, analog input 1 |
| Pin 3 | RA2/AN2/VREF- — Bidirectional I/O, analog input 2, ADC VREF- |
| Pin 4 | RA3/AN3/VREF+ — Bidirectional I/O, analog input 3, ADC VREF+ |
| Pin 5 | RA4/T0CKI — Bidirectional I/O, Timer0 clock input |
| Pin 6 | RA5/AN4/SS — Bidirectional I/O, analog input 4, SPI slave select |
| Pin 7 | RA6/OSC2/CLKO — Bidirectional I/O, oscillator crystal output |
| Pin 8 | RA7/OSC1/CLKI — Bidirectional I/O, oscillator crystal input |
| Pin 9 | RB0/INT0/FLT0 — Bidirectional I/O, external interrupt 0, ECCP fault input |
| Pin 10 | RB1/INT1 — Bidirectional I/O, external interrupt 1 |
| Pin 11 | RB2/INT2 — Bidirectional I/O, external interrupt 2 |
| Pin 12 | RB3/CCP2 — Bidirectional I/O, CCP2 input/output |
| Pin 13 | RB4 — Bidirectional I/O, interrupt-on-change |
| Pin 14 | RB5 — Bidirectional I/O, interrupt-on-change |
| Pin 15 | RB6/PGC — Bidirectional I/O, ICSP clock |
| Pin 16 | RB7/PGD — Bidirectional I/O, ICSP data |
| Pin 17 | VSS — Ground reference |
| Pin 18 | VDD — Positive supply voltage |
| Pin 19 | RC0/PWM1 — Bidirectional I/O, ECCP PWM output 1 |
| Pin 20 | RC1/PWM2 — Bidirectional I/O, ECCP PWM output 2 |
| Pin 21 | RC2/PWM3 — Bidirectional I/O, ECCP PWM output 3 |
| Pin 22 | RC3/SCK/SCL — Bidirectional I/O, SPI/I2C clock |
| Pin 23 | RC4/SDI/SDA — Bidirectional I/O, SPI data in / I2C data |
| Pin 25 | RC5/SDO — Bidirectional I/O, SPI data out |
| Pin 26 | RC6/TX/CK — Bidirectional I/O, EUSART TX/clock |
| Pin 27 | RC7/RX/DT — Bidirectional I/O, EUSART RX/data |
| Pin 28 | RD0 — Bidirectional I/O, Port D bit 0 |
| Pin 29 | RD1 — Bidirectional I/O, Port D bit 1 |
| Pin 30 | RD2 — Bidirectional I/O, Port D bit 2 |
| Pin 31 | RD3 — Bidirectional I/O, Port D bit 3 |
| Pin 32 | RD4 — Bidirectional I/O, Port D bit 4 |
| Pin 33 | RD5 — Bidirectional I/O, Port D bit 5 |
| Pin 34 | RD6 — Bidirectional I/O, Port D bit 6 |
| Pin 35 | RD7 — Bidirectional I/O, Port D bit 7 |
| Pin 36 | VSS — Ground reference |
| Pin 37 | VDD — Positive supply voltage |
| Pin 38 | RE0/RD — Bidirectional I/O, parallel port read control |
| Pin 39 | RE1/WR — Bidirectional I/O, parallel port write control |
| Pin 40 | RE2/CS — Bidirectional I/O, parallel port chip select |
Typical Applications
PIC18F43K20-I/P is suitable for 7 applications: Consumer Appliance Control, Industrial Sensor Node, HVAC and Climate Control, Battery-Powered IoT Device, Educational and Hobby Electronics, Legacy Equipment Retrofit, Smart Energy Sub-Meter.
Consumer Appliance Control
The PIC18F43K20-I/P fits consumer appliance control such as washing machines, microwaves, and coffee machines due to its 36 GPIO, 14-channel 10-bit ADC, and PWM/ECCP peripherals. The 64MHz CPU handles user-interface scanning, motor-driver sequencing, and safety monitoring in real time. Its 1.8V-5.5V supply range simplifies integration with both 3.3V and 5V sensor networks. The 40-PDIP package enables hand-soldering for prototype units and small-batch production.
Recommended
Industrial Sensor Node
Industrial sensor nodes benefit from the PIC18F43K20-I/P's nanoWatt XLP technology (<100 nA sleep current) and 14-channel 10-bit ADC. The device samples analog sensors, buffers data in 512B SRAM, and transmits via EUSART or MSSP SPI/I2C. Battery life extends from months to years with deep-sleep mode between transmissions. The 40-PDIP package supports field-replaceable designs where surface-mount rework is impractical for maintenance crews.
Recommended
HVAC and Climate Control
HVAC control loops benefit from the PIC18F43K20-I/P's ECCP PWM module for variable-speed fan and damper control. The 64MHz clock closes feedback loops at 1ms intervals while leaving headroom for keypad scanning, LCD driving, and serial communication. Its extended -40C to +85C industrial temperature range handles unconditioned equipment-room environments. The 40-PDIP form factor matches legacy thermostat PCB layouts.
Recommended
Battery-Powered IoT Device
Battery-powered IoT applications such as remote sensors and wearables rely on the PIC18F43K20-I/P's nanoWatt XLP sleep modes with sub-100 nA current. The 1.8V minimum supply lets it run from a single Li-ion or two AA cells. The 64MHz active clock supports fast sensor processing then returns to deep sleep, extending coin-cell battery life to years. The 40-PDIP package is preferred for prototyping where hand-assembly is desirable.
Recommended
Educational and Hobby Electronics
The PIC18F43K20-I/P is ideal for educational use thanks to its through-hole 40-PDIP package that fits standard breadboards and IC sockets. Students can program it with MPLAB X IDE and PICkit 3/4 debuggers without SMD reflow infrastructure. Its 36 GPIO, 10-bit ADC, PWM, and serial peripherals expose the full PIC18 instruction set including interrupts, timers, and CCP. The mature PIC18 toolchain produces extensive teaching material.
Recommended
Legacy Equipment Retrofit
Retrofit of legacy industrial and medical equipment uses the PIC18F43K20-I/P because its 40-PDIP package matches original through-hole designs that cannot accept SMD replacements. Modern firmware can replace obsolete logic with PIC18 code while keeping the PCB unchanged. The 1.8V-5.5V supply range handles legacy 5V rails and modern 3.3V subsystems. Drop-in compatibility with PIC18F4320-I/P and PIC18F45K20-I/P enables staged upgrades.
Recommended
Smart Energy Sub-Meter
Smart energy sub-meters use the PIC18F43K20-I/P for measurement and communication. The 14-channel 10-bit ADC samples current shunts and voltage dividers at >1 kHz, while the EUSART and MSSP peripherals drive wireless modules or RS-485 buses. nanoWatt XLP sleep modes minimize idle current for battery-backed meters. The 40-PDIP package simplifies through-hole assembly in field-installed metering hardware.
Recommended
Recommended Products Summary
Engineering reference data for PIC18F43K20-I/P — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC18F45K20-I/P | PIC18F45K22-I/P | PIC18F4321-I/ML | PIC18F4320-I/P | PIC18F4331-I/PT |
|---|---|---|---|---|---|---|
| Package | 40-PDIP (0.600 inch) | 40-PDIP (0.600 inch) - same | 40-PDIP (0.600 inch) - same | 40-PDIP (0.600 inch) - same | 40-PDIP (0.600 inch) - same | 40-PDIP (0.600 inch) - same |
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Program Memory (Flash) | 8 KB | 32 KB | 32 KB | 8 KB | 8 KB | 8 KB |
| RAM | 512 B | 1536 B | 1536 B | 512 B | 512 B | 512 B |
| EEPROM | 256 B | 256 B | 256 B | 256 B | 256 B | 256 B |
| Max Clock Speed | 64 MHz | 64 MHz | 64 MHz | 40 MHz | 40 MHz | 40 MHz |
| Supply Voltage | 1.8 V to 5.5 V | 1.8 V to 5.5 V | 1.8 V to 5.5 V | 4.2 V to 5.5 V | 4.2 V to 5.5 V | 4.2 V to 5.5 V |
| Number of I/O | 36 | 36 | 36 | 36 | 36 | 36 |
| ADC | 10-bit, 14-ch | 10-bit, 14-ch | 10-bit, 30-ch | 10-bit, 13-ch | 10-bit, 13-ch | 10-bit, 9-ch (motor-control PWM focus) |
| nanoWatt XLP | Yes (<100 nA) | Yes (<100 nA) | Yes (<100 nA) | No | No | No |
Key Differentiators
- nanoWatt XLP extreme low power (vs PIC18F4320-I/P)
- Larger RAM and Flash than legacy F4320 (vs PIC18F4320-I/P)
- Through-hole 40-PDIP for legacy retrofit (vs SMD-only PIC18F46K22-I/ML)
Design Notes
The PIC18F43K20-I/P requires a 0.1uF ceramic decoupling capacitor within 5mm of each VDD pin (pins 18 and 37) plus a 10uF bulk capacitor on the main supply rail. For battery applications using nanoWatt XLP modes, add a 1M-ohm pull-up on MCLR to prevent unintended reset from leakage. Verify VDDCORE voltage is stable before enabling peripherals; a 10ms power-on delay is recommended after VDD reaches 90% of nominal.
Do not omit the configuration bits (CONFIG1H/L) when programming - leaving them at default selects the internal RC oscillator and disables the watchdog by default. The ICSP pins RB6/PGD and RB7/PGC must be reserved for in-circuit programming even if not used in the application. Driving PGC as a regular GPIO during programming can lock out further ICSP access. Always include a 10k-ohm pull-up on MCLR and ensure ISP connector access is maintained.
Place the 40-PDIP socket on a 0.1-inch (2.54mm) grid for breadboard compatibility. Keep analog inputs (RA0-RA5) traces short and routed away from digital switching signals to minimize ADC crosstalk. Use a ground plane on the bottom layer with separate analog and digital ground islands joined at a single point near the AVSS pin. For high-frequency operation above 32 MHz, ensure the crystal/oscillator traces are short and guarded with ground.
Compliance Information
RoHS compliant per Microchip product page. Lead-free PDIP package. Not AEC-Q100 qualified - choose PIC18F43K20-E/P (extended temp grade) for non-automotive harsh environments.
