PIC18F66K22-I/PT - 64KB Flash 8-Bit MCU 64MHz TQFP-64 | Microchip
MPN: PIC18F66K22-I/PT ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $6.04 | $6.04 |
| 10 | $5.55 | $55.50 |
| 100 | $4.93 | $493.00 |
| 500 | $4.41 | $2,205.00 |
| 1,000 | $3.96 | $3,960.00 |
PIC18F66K22-I/PT Overview
An 8-bit microcontroller (MCU) is a single-chip computer built around an 8-bit data path that integrates a CPU, non-volatile program memory (Flash), volatile data memory (RAM), non-volatile data memory (EEPROM), and a rich set of peripherals (timers, ADC, communication ports, I/O). 8-bit MCUs sit within the broader semiconductor hierarchy: microcontroller -> embedded processor -> integrated circuit -> semiconductor device. They remain the workhorse of cost-sensitive, deterministic, low-power embedded designs because their instruction sets, toolchains (MPLAB X, XC8), and code portability are mature and well understood.
Key features include up to 53 digital I/O pins, multiple communication peripherals (2x I2C/SPI, 2x UART with LIN, USB 2.0 full-speed), 5 CCP/ECCP modules, two analog comparators, and a 16-bit enhanced timer architecture. The wide 1.8V-5.5V VDD range and nanoWatt XLP modes (sleep current down to the nA range) make the part well suited to battery-powered and energy-harvesting products.
The PIC18F66K22-I/PT combines a Harvard-class RISC core with 16-bit wide instructions, hardware multiply, and a C-friendly compiler target. Its CTMU simplifies robust capacitive-touch key implementation, while the 12-bit ADC supports sensor-system health via accurate signal acquisition. Internal oscillator calibration and a wide operating range (-40C to +85C industrial, -40C to +125C extended) address industrial, automotive, and white-goods environments.
Typical applications include capacitive-touch human-machine interfaces (HMIs), industrial control modules, USB peripherals, low-power remote sensor nodes, and white-goods / appliance controllers. The combination of USB, multiple UARTs, and PWM channels also suits small motor-control and LED-driver boards.
When designing with this part, allocate at least two decoupling capacitors per VDD/AVDD pin (100 nF ceramic + bulk), keep analog and digital grounds separated, and place the 20 MHz external crystal traces short and guarded to minimise jitter on USB and UART baud rates.
This page consolidates distributor pricing as of 2026-09-28, drop-in alternative MPNs in the same TQFP-64 footprint, and practical PCB/thermal guidance not always present on a single manufacturer datasheet page.
Drop-in alternatives for PIC18F66K22-I/PT — 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 PIC18F66K22-I/PT (same form factor and footprint) — differing in Package, Operating Temperature, Timers, Core Architecture, ADC.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PIC18F65K22-I/PT
✅ Drop-In✓ In Stock
$3.45 / Unit
View Datasheet →PIC18F67K22-I/PT
✅ Drop-In✓ In Stock
$4.1 / Unit
View Datasheet →PIC18F66K22-E/PT
✅ Drop-In✓ In Stock
$5.8 / Unit
View Datasheet →PIC18F66K22-I/MRRSL
✅ Drop-In ⚠️ Specs Unverified✓ In Stock
$3.55 / Unit
View Datasheet →PIC18F67J10-I/PT
✅ Drop-In✓ In Stock
$5.4 / Unit
View Datasheet →PIC18F66J55-I/PT
✅ Drop-In✓ In Stock
$4.31 / Unit
View Datasheet →PIC18F66K90-I/PT
✅ Drop-In✓ In Stock
$4.15 / Unit
View Datasheet →PIC18F66K22-I/PT Maximum Ratings & Electrical Characteristics
| Family | PIC18F K-series (PIC18F87K22 family data sheet) |
| Core | PIC18 8-bit RISC, 16-bit instructions, hardware multiply |
| Max CPU Frequency | 64 MHz (16 MIPS) |
| Program Memory (Flash) | 64 KB (32K x 16) |
| Data RAM | 4 KB |
| Data EEPROM | 1 KB |
| Supply Voltage (VDD) | 1.8 V to 5.5 V |
| I/O Pins | Up to 53 |
| ADC | 12-bit, up to 16 channels |
| Communication | USB 2.0 FS, 2x I2C/SPI, 2x EUSART (LIN) |
| Timers | 16-bit timers, 5 CCP/ECCP modules |
| CTMU | Charge Time Measurement Unit (capacitive touch) |
| Comparators | 2x analog comparators |
| Operating Temperature | -40C to +85C (I grade) |
| Package | 64-pin TQFP (PT), 10x10 mm |
| Mounting Type | Surface Mount |
| Low-Power Mode | nanoWatt XLP (nA-range sleep current) |
| MSL Level | 3 (per JEDEC J-STD-020) |
| RoHS Status | Compliant |
PIC18F66K22-I/PT Pin Configuration
| Pin 1 | RC0 — Digital I/O / PWM / comparator output |
| Pin 2 | RC1 — Digital I/O / PWM / ECCP |
| Pin 3 | RC2 — Digital I/O / PWM / ECCP |
| Pin 4 | RC3 — Digital I/O / PWM / SPI clock |
| Pin 5 | RC4 — Digital I/O / PWM / SPI data |
| Pin 6 | RC5 — Digital I/O / PWM |
| Pin 7 | RC6 — Digital I/O / EUSART TX / CTMU |
| Pin 8 | RC7 — Digital I/O / EUSART RX / CTMU |
| Pin 9 | RE0 — Digital I/O / ADC input |
| Pin 10 | RE1 — Digital I/O / ADC input |
| Pin 11 | RE2 — Digital I/O / ADC input |
| Pin 12 | RE3 — Digital I/O / ADC input |
| Pin 13 | RA0 — Digital I/O / ADC input |
| Pin 14 | RA1 — Digital I/O / ADC input |
| Pin 15 | RA2 — Digital I/O / ADC input |
| Pin 16 | RA3 — Digital I/O / ADC input / VREF+ |
| Pin 17 | RA4 — Digital I/O / comparator input |
| Pin 18 | RA5 — Digital I/O / ADC input |
| Pin 19 | RA6 — Digital I/O / oscillator output |
| Pin 20 | RA7 — Digital I/O / oscillator input |
| Pin 21 | VDD — Digital supply voltage |
| Pin 22 | VSS — Digital ground |
| Pin 23 | RB0 — Digital I/O / interrupt-on-change / ECCP |
| Pin 24 | RB1 — Digital I/O / interrupt-on-change |
| Pin 25 | RB2 — Digital I/O / interrupt-on-change |
| Pin 26 | RB3 — Digital I/O / interrupt-on-change |
| Pin 27 | RB4 — Digital I/O / interrupt-on-change |
| Pin 28 | RB5 — Digital I/O / interrupt-on-change / PWM |
| Pin 29 | RB6 — Digital I/O / ICD clock / PWM |
| Pin 30 | RB7 — Digital I/O / ICD data / PWM |
| Pin 31 | VSS — Digital ground |
| Pin 32 | VDD — Digital supply voltage |
| Pin 33 | RD0 — Digital I/O / PWM / ECCP |
| Pin 34 | RD1 — Digital I/O / PWM / ECCP |
| Pin 35 | RD2 — Digital I/O / PWM |
| Pin 36 | RD3 — Digital I/O / PWM |
| Pin 37 | RD4 — Digital I/O / PWM |
| Pin 38 | RD5 — Digital I/O / PWM |
| Pin 39 | RD6 — Digital I/O / PWM |
| Pin 40 | RD7 — Digital I/O / PWM |
| Pin 41 | VSS — Digital ground |
| Pin 42 | VDD — Digital supply voltage |
| Pin 43 | RF0 — Digital I/O / analog comparator |
| Pin 44 | RF1 — Digital I/O / analog comparator |
| Pin 45 | RF2 — Digital I/O / analog comparator |
| Pin 46 | RF3 — Digital I/O / analog comparator |
| Pin 47 | RF4 — Digital I/O / analog comparator |
| Pin 48 | RF5 — Digital I/O / analog comparator |
| Pin 49 | RF6 — Digital I/O / analog comparator |
| Pin 50 | RF7 — Digital I/O / analog comparator |
| Pin 51 | AVSS — Analog ground |
| Pin 52 | AVDD — Analog supply voltage |
| Pin 53 | MCLR — Master Clear (reset) input, programming voltage |
| Pin 54 | OSC1 — External oscillator input / crystal |
| Pin 55 | OSC2 — External oscillator output / crystal |
| Pin 56 | RA5 — Digital I/O / ADC input (alt position on PT) |
| Pin 57 | D+ — USB D+ data line |
| Pin 58 | D- — USB D- data line |
| Pin 59 | VUSB — USB internal transceiver supply |
| Pin 60 | RG0 — Digital I/O / CCP / PWM |
| Pin 61 | RG1 — Digital I/O / CCP / PWM |
| Pin 62 | RG2 — Digital I/O / CCP / PWM |
| Pin 63 | RG3 — Digital I/O / CCP / PWM |
| Pin 64 | RG4 — Digital I/O / CCP / PWM |
Typical Applications
PIC18F66K22-I/PT is suitable for 6 applications: Capacitive-Touch HMI Panels, USB Human Interface Devices (HID), Industrial Sensor Acquisition Nodes, White Goods and Appliance Control, Low-Power Remote Control / IoT Edge Node, Small BLDC / DC Motor Control Boards.
Capacitive-Touch HMI Panels
The PIC18F66K22-I/PT's integrated Charge Time Measurement Unit (CTMU) and 12-bit ADC with up to 16 channels are the core reason it fits capacitive-touch human-machine interfaces. CTMU generates a precision current source and measures discharge time of the touch-sensor capacitance via the ADC, removing the need for an external touch controller IC. In a typical 4x4 keypad or slider panel, the MCU scans each electrode, computes a touch/no-touch delta in firmware, and updates the host. Designers achieve robust touch sensing under wet or noisy conditions when paired with the application note AN1258 layout and firmware libraries. The 64 KB Flash fits Microchip's mTouch reference code plus application logic. NanoWatt XLP sleep currents keep battery-powered remote controls awake for years on a coin cell.
Recommended
USB Human Interface Devices (HID)
The PIC18F66K22-I/PT integrates a USB 2.0 full-speed transceiver and Serial Interface Engine, eliminating external PHY chips and saving BOM cost in keyboards, mice, game controllers, and custom HID peripherals. The MCU enumerates as HID, CDC, or vendor-class via Microchip's MLA USB stack, with descriptors stored in Flash. At 64 MHz the 8-bit core handles 12 Mbps USB traffic plus HID report processing with headroom. The 53 I/O pins support large matrix key scans (8x16) or analog joysticks via the 12-bit ADC. A 1.5 kohm pull-up on D+ is required, and D+/D- traces must be 90 ohm differential per USB 2.0 layout rules. Compared to a separate USB-to-UART bridge plus MCU, this single-chip solution cuts cost and PCB area.
Recommended
Industrial Sensor Acquisition Nodes
The PIC18F66K22-I/PT's 12-bit ADC (up to 16 channels), 1.8 V to 5.5 V VDD range, and -40C to +85C industrial temperature grade make it a strong fit for multi-sensor acquisition in industrial nodes. The MCU digitises 4-20 mA loop sensors, RTDs, thermistors, and bridge pressure sensors at low sample rates while running Modbus RTU over EUSART or LIN. NanoWatt XLP reduces idle current to support battery-powered wireless sensor nodes that wake every few seconds to take a reading. CTMU enables accurate resistance measurement for ratiometric sensor compensation. The 4 KB RAM buffers sensor data, while the 1 KB EEPROM stores calibration constants and node IDs across firmware updates.
Recommended
White Goods and Appliance Control
The PIC18F66K22-I/PT delivers the I/O count, ADC channels, and PWM outputs needed to drive white-goods and appliance control boards - washing machines, dishwashers, ovens, and induction cooktops. Five CCP/ECCP modules provide PWM for motor speed control, while the 12-bit ADC reads thermistors, water-level sensors, and door switches. The 1.8 V to 5.5 V VDD range allows direct connection to 5 V or 3.3 V sensor rails. EUSART with LIN support enables LIN-bus appliance networking. NanoWatt XLP standby modes reduce energy consumption in energy-star appliances. The 64-pin TQFP gives enough I/O for displays, keypads, and relay drivers without external I/O expanders.
Recommended
Low-Power Remote Control / IoT Edge Node
The PIC18F66K22-I/PT's nanoWatt XLP technology enables sleep currents in the nA range, which is the key reason it fits battery-powered remote controls and edge IoT nodes. The MCU spends most of its time in sleep, waking periodically (or via an interrupt) to read a sensor or transmit a packet over UART, SPI, or a sub-GHz radio companion. The wide 1.8 V to 5.5 V VDD range supports single-cell Li-ion, 2xAA, or coin-cell battery stacks. EUSART LIN-capable and MSSP SPI/I2C interfaces connect to radios (RN2483, MRF24J40) and sensors. Designers typically achieve 2-5 year battery life on 2xAA in periodic-sensing duty cycles.
Recommended
Small BLDC / DC Motor Control Boards
The PIC18F66K22-I/PT's 5 CCP/ECCP modules and 16-bit timers provide the PWM and capture channels needed for small brushless-DC (BLDC) and brushed-DC motor control. The 64 MHz core executes PI/PID current and speed loops at >20 kHz PWM, while the 12-bit ADC samples back-EMF and current-sense amplifier outputs. Up to 53 I/O pins drive gate drivers, Hall-effect sensor inputs, and quadrature encoder feedback. The integrated USB helps with debugging, factory tuning, and firmware updates. Compared with dedicated motor-control MCUs, the PIC18F66K22-I/PT offers lower cost when high-resolution PWM (above 1 ns) is not required. Pair it with an MCP14A0901T MOSFET driver for sub-100 W appliances and small pumps.
Recommended
Recommended Products Summary
Engineering reference data for PIC18F66K22-I/PT — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC18F65K22-I/PT | PIC18F67K22-I/PT | PIC18F66K22-E/PT | PIC18F66K90-I/PT | PIC18F66J55-I/PT |
|---|---|---|---|---|---|---|
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Package | 64-pin TQFP (10x10 mm) | 64-pin TQFP - same | 64-pin TQFP - same | 64-pin TQFP - same | 64-pin TQFP - same | 64-pin TQFP - same |
| Flash | 64 KB | 64 KB | 128 KB (+100%) | 64 KB | 64 KB | 96 KB (+50%) |
| RAM | 4 KB | 4 KB | 4 KB | 4 KB | 4 KB | 3.6 KB |
| EEPROM | 1 KB | 1 KB | 1 KB | 1 KB | 1 KB | 0 (no EEPROM) |
| Max CPU Frequency | 64 MHz | 64 MHz | 64 MHz | 64 MHz | 64 MHz | 48 MHz |
| Supply Voltage (VDD) | 1.8 V to 5.5 V | 1.8 V to 5.5 V | 1.8 V to 5.5 V | 1.8 V to 5.5 V | 1.8 V to 5.5 V | 2.0 V to 3.6 V (narrower) |
| USB | USB 2.0 Full-Speed integrated | USB 2.0 FS | USB 2.0 FS | USB 2.0 FS | USB 2.0 FS | USB 2.0 FS OTG |
| Operating Temperature | -40C to +85C (I grade) | -40C to +85C | -40C to +85C | -40C to +125C (E grade) | -40C to +85C | -40C to +85C |
Key Differentiators
- Integrated CTMU for capacitive touch without external IC (vs PIC18F65K22-I/PT)
- 128 KB Flash upgrade path in the same footprint (vs PIC18F67K22-I/PT)
- Extended temperature grade variant available (vs PIC18F66K22-E/PT)
- USB OTG support for host/device flexibility (vs PIC18F66J55-I/PT)
Design Notes
Place a 100 nF ceramic decoupling capacitor within 3 mm of every VDD/VSS pin pair on the PIC18F66K22-I/PT; the TQFP-64 has multiple VDD pins (pins 21, 32, 42) and VSS pins (22, 31, 41) that must each be locally decoupled. Add a single 10 uF bulk capacitor near the package. For AVDD/AVSS (pins 52/51), use a separate LC or ferrite-filtered rail and a dedicated 100 nF cap to keep ADC noise low. Inadequate decoupling is the most common root cause of USB enumeration failures and ADC noise on PIC18 K-series designs.
For USB designs using the PIC18F66K22-I/PT, route D+ (pin 57) and D- (pin 58) as a 90 ohm differential pair with matching length and ground reference on both sides; this is required for USB 2.0 full-speed signal integrity. Keep the pair away from switching nodes (PWM, gate drivers) and away from the crystal oscillator traces. Place the 1.5 kohm pull-up resistor on D+ within 4 mm of the pin, and ensure the VUSB pin has its own 100 nF + 4.7 uF bulk capacitor. These layout rules match Microchip application note AN1166.
Do not assume the PIC18F66K22-I/PT's configuration words are the same as earlier PIC18F K-series parts - check CONFIG1H, CONFIG2L, and CONFIG3H for PLL enable, oscillator selection, and watchdog timing. According to Microchip's PIC18F87K22 family datasheet, omitting the PLL configuration bit prevents 64 MHz operation. Also, leave unused I/O pins configured as outputs and tied low, or as inputs with the internal weak pull-up enabled; floating unused pins can cause excess current in sleep mode.
Keep analog signals (ADC inputs, CTMU, comparator inputs) physically separated from digital switching traces. Use a single-point ground connection between the analog ground plane (AVSS) and the digital ground plane (VSS) to avoid ground loops. Route the external 20 MHz crystal traces (OSC1/OSC2, pins 54/55) within 5 mm of the MCU, guard them with a ground pour, and avoid routing any signal traces under the crystal. These layout practices are documented in Microchip TB3066 (PCB layout for PIC MCUs).
Compliance Information
RoHS and lead-free compliant per Microchip product page. Not AEC-Q100 qualified; for automotive applications consult Microchip's automotive-grade PIC18 portfolio. Country of Origin: Philippines or Thailand per MicrochipDirect.
