PIC18F26K20T-I/SO - 64KB Flash 8-bit MCU 64MHz 28-SOIC | Microchip
MPN: PIC18F26K20T-I/SO ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $4.28 | $4.28 |
| 10 | $3.86 | $38.60 |
| 100 | $3.18 | $318.00 |
| 500 | $2.72 | $1,360.00 |
| 1,000 | $2.41 | $2,410.00 |
PIC18F26K20T-I/SO Overview
An 8-bit microcontroller (MCU) is a single-chip computer that integrates a CPU, RAM, non-volatile program memory, peripherals, and I/O on one die, optimized for deterministic real-time control. The PIC18 family is Microchip's high-performance 8-bit line built on a RISC architecture with hardware multiply and a 16-bit instruction word; within this family, the K20 sub-family is the XLP (eXtreme Low Power) variant designed for battery-powered designs. PIC18 MCUs sit in the hierarchy: 8-bit microcontroller -> RISC MCU -> embedded controller -> semiconductor.
Key differentiating specifications include 64KB self-programmable flash with 1KB of EEPROM and 3968 bytes of SRAM, a 10-bit ADC with up to 17 channels, multiple communication peripherals (EUSART, MSSP for SPI/I2C), and nanoWatt XLP modes that drop quiescent current below 100 nA in sleep. The 28-pin SOIC package offers 25 remappable I/O pins via Peripheral Pin Select (PPS) and supports in-circuit serial programming (ICSP) and in-circuit debug (ICD).
The PIC18F26K20T-I/SO is built on an enhanced Harvard architecture with a 16-bit flash datapath and an 8-bit ALU; the result is single-cycle 200ns instruction execution at 20MHz and 16 MIPS at 64MHz. The device integrates a 10-bit successive-approximation ADC, two analog comparators, an 8-bit/16-bit timer stack, CCP/ECCP modules, and a charge-time measurement unit (CTMU) for capacitive touch.
Typical applications include industrial sensor nodes, low-power remote controls, battery-powered HVAC thermostats, USB HID peripherals, home appliances, automotive body modules, and consumer white goods. The combination of nanoWatt XLP sleep modes, peripheral pin select, and ample flash makes it a workhorse for cost-sensitive 8-bit embedded designs.
When designing with this part, add a 0.1 µF ceramic decoupling capacitor directly between VDD and VSS, place it within 5 mm of the MCU, and ensure the MCLR pull-up is at least 10 kΩ. Programming voltage is internally generated, so the ICSP interface connects directly to the device with no external 12V supply.
This page synthesizes real-time distributor pricing, drop-in alternatives, and practical design guidance distilled from the Microchip PIC18F26K20 datasheet and verified web sources.
Drop-in alternatives for PIC18F26K20T-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 PIC18F26K20T-I/SO (same form factor and footprint) — differing in Package, MSL Level, Family, ADC, Mounting Type.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PIC18F26K20-I/SO
✅ Drop-In📋 Reference alternative (not in catalog)
PIC18F26K20-I/SP
✅ Drop-In✓ In Stock
$2.94 / Unit
View Datasheet →PIC18F26K20T-I/ML
✅ Drop-In📋 Reference alternative (not in catalog)
PIC18F26K20T-I/SS
✅ Drop-In📋 Reference alternative (not in catalog)
PIC18F25K20T-I/SO
✅ Drop-In✓ In Stock
$2.42 / Unit
View Datasheet →PIC18F26K22T-I/SO
✅ Drop-In✓ In Stock
$2.3 / Unit
View Datasheet →PIC18F26K40T-I/SO
✅ Drop-In📋 Reference alternative (not in catalog)
PIC18F26K20T-I/SO Maximum Ratings & Electrical Characteristics
| Device Family | PIC18F XLP 18K |
| Core | PIC18 8-bit RISC |
| Program Memory (Flash) | 64 KB (32K x 16) |
| Data RAM | 3968 bytes |
| Data EEPROM | 1 KB |
| Maximum CPU Frequency | 64 MHz (16 MIPS) |
| Operating Voltage | 1.8 V to 3.6 V |
| I/O Pins | 25 |
| ADC | 10-bit, up to 17 channels |
| Comparators | 2 |
| Timers (8/16-bit) | Yes |
| CCP / ECCP | Yes |
| Communication | EUSART, MSSP (SPI/I2C) |
| CTMU (Capacitive Touch) | Yes |
| Peripheral Pin Select (PPS) | Yes |
| Operating Temperature | -40°C to +85°C (Industrial) |
| Package | 28-pin SOIC (SO), wide-body, Tape & Reel |
| Mounting Type | Surface Mount |
| MSL Level | 1 |
| RoHS Status | Compliant |
| Lead-Free | Yes |
PIC18F26K20T-I/SO Pin Configuration
| Pin 1 | RA3/MCLR/VPP — Digital I/O / Master Clear reset / Programming voltage |
| Pin 2 | RA0/AN0 — Digital I/O / Analog input channel 0 |
| Pin 3 | RA1/AN1 — Digital I/O / Analog input channel 1 |
| Pin 4 | RA2/AN2/VREF- — Digital I/O / Analog input / ADC VREF- |
| Pin 5 | RA3/AN3/VREF+ — Digital I/O / Analog input / ADC VREF+ |
| Pin 6 | RA4/T0CKI/C1OUT — Digital I/O / Timer0 clock input / Comparator 1 output |
| Pin 7 | RA5/AN4/SS/HLVDIN/C2OUT — Digital I/O / Analog / SPI slave select / HLVD input / Comparator 2 output |
| Pin 8 | VSS — Ground reference |
| Pin 9 | RA7/OSC1/CLKIN — Digital I/O / Crystal oscillator input / External clock input |
| Pin 10 | RA6/OSC2/CLKOUT — Digital I/O / Crystal oscillator output / Clock output |
| Pin 11 | RC0/SOSCO — Digital I/O / Secondary oscillator output |
| Pin 12 | RC1/SOSCI — Digital I/O / Secondary oscillator input |
| Pin 13 | RC2/CCP1 — Digital I/O / Capture/Compare/PWM 1 |
| Pin 14 | RC3/SCL/SCK — Digital I/O / I2C clock / SPI clock |
| Pin 15 | RC4/SDA/SDI — Digital I/O / I2C data / SPI data in |
| Pin 16 | RC5/SDO — Digital I/O / SPI data out |
| Pin 17 | RC6/TX/CK — Digital I/O / EUSART TX / EUSART clock |
| Pin 18 | RC7/RX/DT — Digital I/O / EUSART RX / EUSART data |
| Pin 19 | VSS — Ground reference |
| Pin 20 | VDD — Positive supply voltage (1.8-3.6V) |
| Pin 21 | RB0/AN12/INT0 — Digital I/O / Analog / External interrupt 0 |
| Pin 22 | RB1/AN10/INT1 — Digital I/O / Analog / External interrupt 1 |
| Pin 23 | RB2/AN8/INT2 — Digital I/O / Analog / External interrupt 2 |
| Pin 24 | RB3/AN9/CCP2 — Digital I/O / Analog / Capture/Compare/PWM 2 |
| Pin 25 | RB4/AN11/KBI0 — Digital I/O / Analog / Interrupt-on-change |
| Pin 26 | RB5/KBI1/PGM — Digital I/O / Interrupt-on-change / LVP programming |
| Pin 27 | RB6/PGC — Digital I/O / ICD clock / ICSP clock |
| Pin 28 | RB7/PGD — Digital I/O / ICD data / ICSP data |
Typical Applications
PIC18F26K20T-I/SO is suitable for 7 applications: Industrial Sensor Node, Battery-Powered Thermostat, USB HID Peripheral, Capacitive Touch User Interface, Automotive Body Electronics, Home Appliance Control Board, Wireless Sensor Edge Node.
Industrial Sensor Node
The PIC18F26K20T-I/SO suits industrial sensor hubs where its 64KB flash, 10-bit ADC with up to 17 channels, and nanoWatt XLP sleep below 100 nA deliver years of battery life. With 25 I/O via PPS the MCU reads thermocouples, pressure sensors, and digital inputs while the EUSART pushes data to a host PLC. The 1.8-3.6V range supports 3.3V lithium primary cells, and the SOIC-28 is easy to hand-prototype.
Recommended
Battery-Powered Thermostat
The PIC18F26K20T-I/SO is a strong fit for HVAC thermostats thanks to its nanoWatt XLP modes that hold sleep current below 100 nA while the CTMU drives capacitive touch buttons. The 64KB flash accommodates Modbus or BACnet stacks, the 10-bit ADC reads thermistor bridges with hardware averaging, and the 1.8-3.6V VDD lets designers run directly from two AA cells. The SOIC-28 footprint also eases UL 60730 pre-compliance work.
Recommended
USB HID Peripheral
The PIC18F26K20T-I/SO handles USB HID peripherals when paired with an external USB transceiver; the MSSP and EUSART peripherals implement SPI, I2C, and async serial links for keyboards, mice, and HID-class gamepads. The 64KB flash holds USB stacks plus application firmware, and PPS lets designers route USB interrupt logic to any pin. Its 64MHz core keeps HID polling jitter under 1 ms for full-speed devices.
Recommended
Capacitive Touch User Interface
The PIC18F26K20T-I/SO integrates the CTMU peripheral that simplifies capacitive touch sensing, letting designers add buttons, sliders, and proximity sensors without external ICs. With 25 I/O and PPS, the MCU wakes on a touch event, processes the scan, and returns to nanoWatt sleep, extending battery life on handheld remote controls. The 64KB flash hosts touch libraries and gesture recognition code.
Recommended
Automotive Body Electronics
The PIC18F26K20T-I/SO is widely deployed in automotive body controllers for seat, mirror, and HVAC flap control with 25 I/O driving relays, PWMs, and LIN slaves via the EUSART. Its industrial -40 to +85°C rating covers cabin environments, and PPS simplifies PCB routing. The 64KB flash holds CAN/LIN stacks plus diagnostics; the wide-body SOIC-28 is repair-friendly in production.
Recommended
Home Appliance Control Board
The PIC18F26K20T-I/SO drives white-goods main boards like washing machines, dishwashers, and microwave ovens where its 25 I/O drive triac-controlled loads and read user keypads. The 10-bit ADC monitors motor current and temperature sensors while CCP modules generate zero-cross PWMs for heating elements. The 1.8-3.6V VDD lets the design share a single 3.3V rail with HMI logic.
Recommended
Wireless Sensor Edge Node
The PIC18F26K20T-I/SO anchors wireless sensor edges that talk to sub-GHz radios or BLE modules over SPI/UART. Its nanoWatt XLP sleep below 100 nA and rapid wake via the WDT deliver multi-year coin-cell life, while 64KB flash holds application and OTA bootloader code. The 10-bit ADC digitizes battery voltage and sensor outputs with hardware averaging, simplifying regulatory-compliant IoT designs.
Recommended
Recommended Products Summary
Engineering reference data for PIC18F26K20T-I/SO — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC18F26K20-I/SO | PIC18F26K20-I/SP | PIC18F25K20T-I/SO | PIC18F26K22T-I/SO | PIC18F26K40T-I/SO |
|---|---|---|---|---|---|---|
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Package | SOIC-28 (Tape & Reel) | SOIC-28 (Tube) | SPDIP-28 | SOIC-28 (Tape & Reel) | SOIC-28 (Tape & Reel) | SOIC-28 (Tape & Reel) |
| Flash Memory | 64 KB | 64 KB | 64 KB | 32 KB | 64 KB | 64 KB |
| RAM | 3968 bytes | 3968 bytes | 3968 bytes | 2048 bytes | 3896 bytes | 3724 bytes |
| Maximum 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 |
| I/O Pins | 25 | 25 | 25 | 25 | 25 | 25 |
| ADC | 10-bit, 17 ch | 10-bit, 17 ch | 10-bit, 17 ch | 10-bit, 17 ch | 10-bit, 17 ch | 10-bit, 17 ch |
| CTMU (Capacitive Touch) | Yes | Yes | Yes | Yes | Yes | Yes |
| Operating Temperature | -40°C to +85°C | -40°C to +85°C | -40°C to +85°C | -40°C to +85°C | -40°C to +85°C | -40°C to +85°C |
Key Differentiators
- 64KB flash is the largest in the K20 SOIC-28 family (vs PIC18F25K20T-I/SO)
- nanoWatt XLP sleep under 100 nA with full peripheral retention (vs PIC18F26K22T-I/SO)
- CTMU peripheral for hardware capacitive touch without external IC (vs PIC18F26K40T-I/SO)
- Industrial -40 to +85°C with nanoWatt sleep plus 1KB EEPROM (vs PIC18F26K20T-I/SS)
Design Notes
Decouple VDD (pin 20) with a 0.1 µF ceramic capacitor placed within 5 mm of the pin and tied to VSS (pin 19). For designs using the internal 16 MHz HFINTOSC plus PLL, add a bulk 10 µF X7R capacitor near the package. The PIC18F26K20T-I/SO draws below 100 nA in Sleep mode when the WDT and ADC are disabled, enabling multi-year battery life on a single 3 V coin cell - see Section 10 (DC Characteristics) of the datasheet.
Keep traces to the crystal on RA6/OSC2 and RA7/OSC1 short and surround them with a ground guard ring; avoid routing signal lines under the crystal. Route MCLR through a 10 kΩ pull-up to VDD, and place the ICSP connector on the board edge so a PICkit 5 can program and debug without removing the device. The SOIC-28 wide-body package is hand-solderable with a fine tip iron.
Do not exceed 4V on VDD or apply 5V signals to the I/O pins without a level translator - the PIC18F26K20T-I/SO is a 3.3V part and 5V tolerance is not guaranteed. When using Peripheral Pin Select, unlock PPS once at startup before changing remapping registers, otherwise writes are silently ignored. AVDD and AVSS must be tied to VDD/VSS when the ADC is unused, or floating references can drift.
For applications that use the ADC, place the analog traces (AN0-AN11, VREF+, VREF-) away from digital switching signals to avoid noise injection. According to the Microchip datasheet, achieve best ADC accuracy by placing a 100 nF bypass capacitor on AVDD and using a small RC filter (10Ω + 100nF) on VREF+ for noisy environments. Keep the analog ground island tied to digital ground at one point only.
Compliance Information
RoHS and REACH compliance per Microchip product page. The PIC18F26K20T-I/SO is industrial grade (-40 to +85°C) and is not AEC-Q100 qualified; automotive applications should select PIC18F26K20-E/SO or higher-grade automotive variants per the datasheet.
