PIC18F26K42-I/SO - 64KB Flash 8-bit MCU 28-SOIC | Microchip
MPN: PIC18F26K42-I/SO ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $2.34 | $2.34 |
| 10 | $2.13 | $21.30 |
| 100 | $1.81 | $181.00 |
| 500 | $1.62 | $810.00 |
| 1,000 | $1.43 | $1,430.00 |
PIC18F26K42-I/SO Overview
A microcontroller (MCU) is a single-chip computer that integrates a CPU, non-volatile program memory (typically Flash), volatile data memory (RAM), and a configurable set of digital and analog peripherals on a single die. PIC18 microcontrollers use an 8-bit modified Harvard RISC architecture with a 16-bit instruction word, balancing code density against throughput at clock rates up to 64MHz. The K42 family advances this architecture with up to 15 PPS (Peripheral Pin Select) remappable I/O, enabling flexible PCB layout and reduced trace congestion.
Key specifications of the PIC18F26K42-I/SO include 24 ADC channels with 12-bit resolution and up to 100 ksps conversion rate, two I2C/SPI/I2S-capable MSSP peripherals, two UART modules with LIN/IrDA support, a 10-bit PWM with multiple complementary outputs, and 25 general-purpose I/O pins. The device also features a 5-bit DAC, four 8-bit timers and four 16-bit timers, plus a windowed watchdog timer for safety-critical applications.
The PIC18F26K42 family is built on Microchip's enhanced mid-range core with a 16-bit instruction path, hardware multiplier, and 32-level stack, supporting C-compiled code from MPLAB XC8. XLP technology delivers nanoWatt sleep currents below 50 nA, making the part well suited to battery-powered sensor nodes. According to the Microchip datasheet, the device achieves typical active current of 1.4 mA at 4 MHz and idle mode current under 1 µA.
Typical applications include industrial sensor conditioning, building automation, low-power IoT edge nodes, consumer appliance control, USB-to-UART bridges, and small motor drives via the CWG and PWM peripherals. The wide 2.3V-5.5V supply range allows direct Li-ion battery or USB-bus operation without additional regulators.
When designing with this device, ensure the MSSP peripherals are configured for the desired SPI/I2C mode before assigning pin functions through PPS. Use the on-board 64MHz HFINTOSC or an external crystal for time-critical peripherals such as UART or PWM.
This page synthesizes distributor pricing, drop-in same-package alternatives, and practical design notes not found in the manufacturer datasheet alone.
Drop-in alternatives for PIC18F26K42-I/SO — 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 PIC18F26K42-I/SO (same form factor and footprint) — differing in ADC, Package, DAC, I/O Pins, Comparators.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PIC18F26K42T-I/SO
✅ Drop-In📋 Reference alternative (not in catalog)
PIC18F26K42-E/SO
✅ Drop-In✓ In Stock
$2.54 / Unit
View Datasheet →PIC18F26K42-I/SO Maximum Ratings & Electrical Characteristics
| Product Type | 8-bit Microcontroller (MCU) |
| Family | PIC18 XLP |
| Program Memory (Flash) | 64 KB (32K x 16) |
| RAM | 4 KB |
| EEPROM | 1 KB |
| CPU Speed | 64 MHz |
| Supply Voltage Range | 2.3 V to 5.5 V |
| ADC | 12-bit, 24 channels |
| DAC | 5-bit |
| PWM Channels | 10-bit, multiple complementary outputs |
| I/O Pins | 25 |
| UART | 2 (LIN/IrDA capable) |
| I2C/SPI/I2S | 2 MSSP peripherals |
| Timers | 4 x 8-bit + 4 x 16-bit |
| Operating Temperature | -40 C to +85 C (Industrial) |
| Package | 28-pin SOIC (300 mil) |
| Mounting Type | Surface Mount |
| RoHS Status | Compliant |
PIC18F26K42-I/SO Pin Configuration
| Pin 1 | RA2 — Port A bit 2 (PPS-capable analog/digital I/O) |
| Pin 2 | RA3 — Port A bit 3 (PPS-capable analog/digital I/O) |
| Pin 3 | RA4 — Port A bit 4 (PPS-capable analog/digital I/O) |
| Pin 4 | RA5 — Port A bit 5 (PPS-capable analog/digital I/O) |
| Pin 5 | RA6 — Port A bit 6 / OSC2 |
| Pin 6 | RA7 — Port A bit 7 / OSC1 |
| Pin 7 | VSS — Ground reference |
| Pin 8 | VDD — Positive supply voltage (2.3V-5.5V) |
| Pin 9 | RB0 — Port B bit 0 (PPS-capable, INT0) |
| Pin 10 | RB1 — Port B bit 1 (PPS-capable, INT1) |
| Pin 11 | RB2 — Port B bit 2 (PPS-capable) |
| Pin 12 | RB3 — Port B bit 3 (PPS-capable) |
| Pin 13 | RB4 — Port B bit 4 (PPS-capable) |
| Pin 14 | RB5 — Port B bit 5 (PPS-capable) |
| Pin 15 | RB6 — Port B bit 6 / PGC (ICSP clock) |
| Pin 16 | RB7 — Port B bit 7 / PGD (ICSP data) |
| Pin 17 | VDD — Positive supply voltage (2.3V-5.5V) |
| Pin 18 | VSS — Ground reference |
| Pin 19 | RC0 — Port C bit 0 (PPS-capable analog/digital I/O) |
| Pin 20 | RC1 — Port C bit 1 (PPS-capable analog/digital I/O) |
| Pin 21 | RC2 — Port C bit 2 (PPS-capable analog/digital I/O) |
| Pin 22 | RC3 — Port C bit 3 (PPS-capable analog/digital I/O) |
| Pin 23 | RC4 — Port C bit 4 (PPS-capable analog/digital I/O) |
| Pin 24 | RC5 — Port C bit 5 (PPS-capable analog/digital I/O) |
| Pin 25 | RC6 — Port C bit 6 (PPS-capable analog/digital I/O) |
| Pin 26 | RC7 — Port C bit 7 (PPS-capable analog/digital I/O) |
| Pin 27 | RE3 — Port E bit 3 (MCLR#/input only) |
| Pin 28 | RA0 — Port A bit 0 (PPS-capable analog/digital I/O) |
Typical Applications
PIC18F26K42-I/SO is suitable for 7 applications: Industrial Sensor Conditioning Hub, Battery-Powered IoT Edge Node, Consumer Appliance Control Panel, Building Automation Node, Small BLDC Motor Drive Controller, USB-to-UART Bridge Module, Smart Agriculture Sensor Cluster.
Industrial Sensor Conditioning Hub
The PIC18F26K42-I/SO is ideal for industrial 4-20 mA sensor conditioning hubs where its 12-bit ADC with 24 channels and 2.3-5.5V supply range handle multiple analog inputs from a single 24V-bus-derived rail. The Core Independent Peripherals (CLC) let engineers build hardware debounce and threshold detection offloading the CPU, while PPS allows signal routing optimization across PCB layers. With 64 KB Flash and 4 KB RAM, the device stores calibration coefficients, runs linearization algorithms, and exposes data via UART or I2C to a host PLC. The XLP idle current below 1 microamp supports battery-backed operation during plant power dips. Designers should average four ADC samples for 50/60 Hz line-noise rejection in line-powered installations.
Recommended
Battery-Powered IoT Edge Node
For battery-powered IoT edge nodes the PIC18F26K42-I/SO's nanoWatt XLP sleep currents below 50 nA extend coin-cell life to multiple years, while the 64 MHz HFINTOSC delivers 16 MIPS for protocol processing when awake. The integrated DMA controller offloads I2C/SPI transactions from the CPU, keeping the core in sleep most of the time. With 64 KB Flash and 4 KB RAM, firmware can host a LoRaWAN or BLE-through-SPI stack alongside application logic. The 2.3-5.5V operating range accommodates direct Li-ion or 3.6V primary battery chemistries without additional regulation. Designers should use the CLC for hardware event correlation to minimize wake cycles and preserve battery capacity.
Recommended
Consumer Appliance Control Panel
The PIC18F26K42-I/SO fits consumer appliance control panels (washers, ovens, HVAC) thanks to its 25 GPIO pins driving capacitive touch via the CLC and CVD modules, plus a 10-bit PWM with complementary outputs for triac-style phase control. The 64 MHz CPU handles real-time display refresh on character LCDs while servicing UART commands from a master inverter board. Industrial temperature grade and 5V tolerance simplify interfacing with legacy opto-isolated triac drivers common in appliance mains stages. The 28-pin SOIC package supports through-hole or SMT assembly on white-goods production lines. Designers should debounce mechanical inputs using the CLC to reduce firmware complexity and improve long-term reliability.
Recommended
Building Automation Node
In BACnet or Modbus building-automation nodes the PIC18F26K42-I/SO provides 2 UART ports for RS-485 trunks plus 2 MSSP for SPI sensor arrays, all mapped via PPS to any of the 25 I/O pins to ease PCB layout in DIN-rail enclosures. The 12-bit ADC reads thermistor inputs for HVAC zone control, and the CLC implements glitch-free line-crossing detection for AC dimming outputs. Wide 2.3-5.5V supply lets the device share a 24V-buck-derived rail common in building controls. 64 KB Flash accommodates BACnet MS/TP stack plus application logic without external memory. Designers should use the windowed watchdog timer to recover from firmware lockup in unattended installations.
Recommended
Small BLDC Motor Drive Controller
The PIC18F26K42-I/SO operates as the controller in low-voltage BLDC fans, pumps, and small appliances, where the Complementary Waveform Generator (CWG) and 10-bit PWM produce center-aligned switching waveforms for three-phase FET bridges. The CLC and DMA offload Hall-sensor or sensorless BEMF zero-cross detection, allowing the CPU to focus on speed-loop math at 64 MHz. With 64 KB Flash and 4 KB RAM the device stores speed profiles and supports FOC-light algorithms. Industrial temperature grade suits under-hood automotive and outdoor installations. Designers should verify PWM resolution versus switching frequency to avoid ADC sampling jitter in current-sense loops.
Recommended
USB-to-UART Bridge Module
Although the PIC18F26K42-I/SO lacks native USB, it pairs with an external MCP2200 or MCP2221 USB-to-UART bridge to deliver a compact serial console or field-programming module, using the K42's two UART ports and 4 KB RAM to buffer protocol traffic. The MSSP ports also expose SPI/I2C to the host PC, turning the design into a multi-protocol adapter for factory test fixtures. Industrial temperature grade and 28-SOIC packaging suit ruggedized enclosure designs. Designers should enable hardware flow control (CTS/RTS) for high-speed UART operation above 115200 baud to avoid FIFO overruns.
Recommended
Smart Agriculture Sensor Cluster
The PIC18F26K42-I/SO consolidates soil moisture, pH, and ambient sensors in smart-agriculture clusters, where its 12-bit ADC reads multiple analog channels and its two I2C buses connect to digital sensor ICs concurrently. XLP nanoWatt sleep below 50 nA is critical for solar-battery-powered field deployments where duty cycle is below 1%. PPS reassigns peripheral pins so PCB antenna and sensor placement can be optimized for weatherproof enclosures. With 64 KB Flash and 4 KB RAM the device holds LoRaWAN-class MAC stacks plus calibration tables for soil sensors. Designers should use the windowed watchdog and brown-out reset to survive brown-outs on long solar-cable runs.
Recommended
Recommended Products Summary
Engineering reference data for PIC18F26K42-I/SO — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC18F26K42T-I/SO | PIC18F26K42-E/SO |
|---|---|---|---|
| Package | 28-SOIC (300 mil) | 28-SOIC (300 mil) - same | 28-SOIC (300 mil) - same |
| Brand | Microchip Technology | Microchip Technology - same | Microchip Technology - same |
| Flash Memory | 64 KB | 64 KB | 64 KB |
| RAM | 4 KB | 4 KB | 4 KB |
| EEPROM | 1 KB | 1 KB | 1 KB |
| CPU Speed | 64 MHz | 64 MHz | 64 MHz |
| Operating Temperature | -40C to +85C (Industrial) | -40C to +85C (Industrial) | -40C to +125C (Extended) |
| Shipping Carrier | Tube | Tape and Reel | Tube |
| Price (1 pc, USD) | 2.34 | 2.34 | 2.65 |
Key Differentiators
- Core Independent Peripherals (CLC, CWG, NCO, DMA) eliminate the need for external logic (vs PIC18F25K22-I/SO)
- Industry-leading nanoWatt XLP technology for sub-50 nA sleep (vs PIC18F26K40-I/SS)
- PPS (Peripheral Pin Select) on nearly every I/O pin (vs PIC18F25K50-I/SO)
Design Notes
Estimated: Decouple each VDD/VSS pair with a 100 nF ceramic capacitor placed within 5 mm of the package pin and a bulk 4.7 uF tantalum or ceramic at the board entry point. The PIC18F26K42-I/SO supports an operating range of 2.3V-5.5V, but switching thresholds and ADC linearity degrade below 3.0V; therefore operate the ADC above 3.0V for production designs.
Configure PPS (Peripheral Pin Select) before assigning any peripheral function to a pin. Unlocked PPS settings can lead to peripherals being mapped to the wrong pins at runtime, causing silent communication failures. Use the MPLAB Code Configurator to generate lock-protected PPS initialization code, and lock the PPS registers at the end of firmware initialization to prevent accidental reprogramming during in-field updates.
Route the ICSP PGC/PGD traces (RB6/RB7) away from switching signals to avoid programming glitches. Use a 4.7 kohm pull-up on MCLR#/RE3 to prevent spurious resets during power-up. Keep the 28-SOIC footprint within 5 mm of the decoupling caps, and provide at least 2 oz copper on the ground pour under the device to improve thermal dissipation for high-FCPU 64 MHz operation.
When using the 64 MHz HFINTOSC at maximum frequency, the ADC requires a minimum acquisition time of 8 us; therefore insert a delay between channel switch and conversion start. For UART communication at 115200 baud, enable the auto-baud feature or use the EUSART with a 16x oversampling clock to minimize framing errors. The MSSP modules support both I2C and SPI but require configuration to lock the SDA/SCL direction before enabling I2C mode.
Compliance Information
RoHS and REACH compliant per Microchip product page. Industrial -40C to +85C temperature grade; for extended -40C to +125C use the PIC18F26K42-E/SO variant. Not AEC-Q100 qualified; for automotive applications consider the PIC18F26K42-I/SO with explicit automotive qualification documentation.
