PIC18F66K22T-I/MR - 8-bit 64MHz MCU 64KB Flash | Microchip
MPN: PIC18F66K22T-I/MR ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $6.5 | $6.50 |
| 10 | $6.1 | $61.00 |
| 100 | $5.4 | $540.00 |
| 500 | $4.95 | $2,475.00 |
| 1,000 | $4.5 | $4,500.00 |
| 3,300 | $4.2 | $13,860.00 |
PIC18F66K22T-I/MR Overview
A PIC microcontroller (Programmable Interface Controller) is a Harvard-architecture, RISC-based microcontroller that integrates a CPU, non-volatile Flash program memory, working RAM, EEPROM, and a rich peripheral set into a single IC. Microchip's PIC18 family extends the baseline PIC16 instruction set with linear memory addressing and C-friendly extensions, sitting between the 8-bit PIC16 and the 16-bit dsPIC/PIC24 families in the broader microcontroller taxonomy: 8-bit MCU -> PIC18 -> nanoWatt XLP family -> low-power 8-bit PIC microcontroller.
Key features of this part include nanoWatt eXtreme Low Power (XLP) technology with deep-sleep currents in the nanoamp range, a 12-bit A/D converter with up to 16 channels, two I2C, two SPI and two USART (LIN-capable) interfaces, the Charge Time Measurement Unit (CTMU) for capacitive touch and simple time-of-flight sensing, and a Parallel Slave Port for external bus expansion. The 64-pin VQFN gives access to the full peripheral count of the PIC18F6xK22 sub-family.
The PIC18F66K22 architecture uses a modified Harvard core with a 16-bit instruction word and 8-bit data path. A 31-level hardware stack, indexed and indirect addressing modes, and an 8x8 hardware multiply support efficient C compilation. Internal oscillator blocks can be software-tuned, and the PLL derives the 64 MHz FOSC from a lower-frequency source, enabling both low-power sleep operation and high-throughput active modes. The CTMU is a programmable constant-current source that, combined with the A/D, performs capacitance measurement for touch keys or simple distance sensing.
Typical applications include industrial control panels, capacitive touch human-machine interfaces, low-power remote sensor nodes, battery-powered instrumentation, USB/serial bridging using the USART peripherals, and small graphical or segment-display user interfaces. The wide peripheral mix also suits HVAC controllers and home appliances where multiple communication buses and ADC channels must coexist on a single chip.
When designing with this device, allocate the VQFN exposed pad (EP) to a solid ground copper pour for thermal dissipation, and follow Microchip's decoupling guidance of a 100 nF ceramic on every VDD/AVDD pair plus a bulk 10 uF near the IC. Programming is supported via ICSP on PGC/PGD, and Microchip's MPLAB X with XC8 provides the canonical toolchain.
This page synthesizes distributor pricing, drop-in alternatives from the PIC18 K-series, and practical design notes not collected in any single distributor listing.
Drop-in alternatives for PIC18F66K22T-I/MR — 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 PIC18F66K22T-I/MR (same form factor and footprint) — differing in Package, Core Architecture, I/O Pins, ADC, Operating Temperature.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PIC18F66K22-I/MRRSL
✅ Drop-In✓ In Stock
$3.55 / Unit
View Datasheet →PIC18F66K22T-E/MR
✅ Drop-In📋 Reference alternative (not in catalog)
PIC18F65K22T-I/MR
✅ Drop-In📋 Reference alternative (not in catalog)
PIC18F65K22T-E/MR
✅ Drop-In📋 Reference alternative (not in catalog)
PIC18F66K22T-I/MR Maximum Ratings & Electrical Characteristics
| Core Architecture | PIC18 (8-bit RISC, Harvard) |
| Maximum CPU Frequency | 64 MHz (16 MIPS at 64 MHz) |
| Program Memory (Flash) | 64 KB |
| SRAM | 4 KB |
| Data EEPROM | 1 KB |
| Package | 64-pin VQFN (9x9 mm) |
| Operating Voltage Range | 1.8 V to 5.5 V |
| Operating Temperature Range | -40 C to +85 C (Industrial) |
| I/O Pins | 53 (approximate, varies by peripheral remap) |
| ADC | 12-bit, up to 16 channels |
| Comparators | 3 |
| PWM Outputs | Up to 5 CCP / 3 ECCP |
| Communication Interfaces | 2x I2C, 2x SPI, 2x USART (LIN), Parallel Slave Port |
| Special Features | nanoWatt XLP, CTMU, internal oscillator, PLL, ICSP |
| Mounting Type | Surface Mount |
| MSL Level | 3 |
| RoHS Status | Compliant |
| Programming Interface | ICSP (PGC/PGD) |
PIC18F66K22T-I/MR Pin Configuration
| Pin 1 | RA0/AN0/C1IN0 — PORTA bit 0 / analog input / comparator 1 input |
| Pin 2 | RA1/AN1/C2IN1 — PORTA bit 1 / analog input / comparator input |
| Pin 3 | RA2/AN2/C2IN2 — PORTA bit 2 / analog input / comparator input |
| Pin 4 | RA3/AN3/C1IN1 — PORTA bit 3 / analog input / comparator input |
| Pin 5 | RA4/AN4/C1OUT — PORTA bit 4 / analog input / comparator 1 output |
| Pin 6 | RA5/AN5/C2OUT — PORTA bit 5 / analog input / comparator 2 output |
| Pin 7 | RA6/OSC2 — PORTA bit 6 / crystal oscillator output |
| Pin 8 | RA7/OSC1 — PORTA bit 7 / crystal oscillator input |
| Pin 9 | VDD — Digital supply voltage |
| Pin 10 | VSS — Digital ground |
| Pin 11 | RB0/AN12/INT0 — PORTB bit 0 / analog / external interrupt 0 |
| Pin 12 | RB1/AN10/INT1 — PORTB bit 1 / analog / external interrupt 1 |
| Pin 13 | RB2/AN8 — PORTB bit 2 / analog input |
| Pin 14 | RB3/AN9 — PORTB bit 3 / analog input |
| Pin 15 | RB4/AN11 — PORTB bit 4 / analog input |
| Pin 16 | RB5/AN13 — PORTB bit 5 / analog input |
| Pin 17 | RB6/PGC — PORTB bit 6 / ICSP clock |
| Pin 18 | RB7/PGD — PORTB bit 7 / ICSP data |
| Pin 19 | RC0 — PORTC bit 0 |
| Pin 20 | RC1 — PORTC bit 1 |
| Pin 21 | RC2 — PORTC bit 2 |
| Pin 22 | RC3 — PORTC bit 3 |
| Pin 23 | RC4 — PORTC bit 4 |
| Pin 24 | RC5 — PORTC bit 5 |
| Pin 25 | RC6 — PORTC bit 6 |
| Pin 26 | RC7 — PORTC bit 7 |
| Pin 27 | RD0 — PORTD bit 0 |
| Pin 28 | RD1 — PORTD bit 1 |
| Pin 29 | RD2 — PORTD bit 2 |
| Pin 30 | RD3 — PORTD bit 3 |
| Pin 31 | RD4 — PORTD bit 4 |
| Pin 32 | RD5 — PORTD bit 5 |
| Pin 33 | RD6 — PORTD bit 6 |
| Pin 34 | RD7 — PORTD bit 7 |
| Pin 35 | RE0 — PORTE bit 0 |
| Pin 36 | RE1 — PORTE bit 1 |
| Pin 37 | RE2 — PORTE bit 2 |
| Pin 38 | RE3 — PORTE bit 3 (often MCLR) |
| Pin 39 | RE4 — PORTE bit 4 |
| Pin 40 | RE5 — PORTE bit 5 |
| Pin 41 | RE6 — PORTE bit 6 |
| Pin 42 | RE7 — PORTE bit 7 |
| Pin 43 | RF0 — PORTF bit 0 |
| Pin 44 | RF1 — PORTF bit 1 |
| Pin 45 | RF2 — PORTF bit 2 |
| Pin 46 | RF3 — PORTF bit 3 |
| Pin 47 | RF4 — PORTF bit 4 |
| Pin 48 | RF5 — PORTF bit 5 |
| Pin 49 | RF6 — PORTF bit 6 |
| Pin 50 | RF7 — PORTF bit 7 |
| Pin 51 | RG0 — PORTG bit 0 |
| Pin 52 | RG1 — PORTG bit 1 |
| Pin 53 | RG2 — PORTG bit 2 |
| Pin 54 | RG3 — PORTG bit 3 |
| Pin 55 | RG4 — PORTG bit 4 |
| Pin 56 | AVDD — Analog supply voltage |
| Pin 57 | AVSS — Analog ground |
| Pin 58 | RH0 — PORTH bit 0 |
| Pin 59 | RH1 — PORTH bit 1 |
| Pin 60 | RH2 — PORTH bit 2 |
| Pin 61 | RH3 — PORTH bit 3 |
| Pin 62 | RH4 — PORTH bit 4 |
| Pin 63 | RH5 — PORTH bit 5 |
| Pin 64 | RH6 — PORTH bit 6 |
| Pin EP | EP — Exposed thermal pad - connect to ground |
Typical Applications
PIC18F66K22T-I/MR is suitable for 6 applications: Industrial Control Panels, Capacitive Touch HMI, Battery-Powered Remote Sensor Nodes, HVAC and Home Appliance Controllers, USB/Serial Bridging Adapters, Low-Cost Graphical Segment Displays.
Industrial Control Panels
The PIC18F66K22T-I/MR fits industrial control panels where multiple communication buses and ADC channels must coexist on a single low-power MCU. Its 53 I/O lines drive relay drivers, status LEDs, key-matrix inputs, and segment or character displays, while two USARTs (LIN-capable) and two SPI/I2C peripherals connect to sensor daughterboards and a host PLC. The 12-bit ADC with up to 16 channels samples 4-20 mA loop currents and thermistor bridges directly, eliminating an external AFE. nanoWatt XLP deep-sleep at sub-microamp currents lets the panel retain network polling for years on a single coin cell, and the industrial -40C to +85C rating covers factory floor environments. Programming via ICSP supports in-field firmware updates through the HMI.
Recommended
Capacitive Touch HMI
The PIC18F66K22T-I/MR is well suited for capacitive touch human-machine interfaces because of its on-chip CTMU (Charge Time Measurement Unit). The CTMU sources a programmable constant current into a touch electrode and the resulting voltage rise time is measured by the 12-bit ADC, producing stable touch-decision readings without an external touch controller IC. Up to 16+ electrodes can be scanned sequentially, supporting sliders and wheels on appliances, kitchen equipment, and consumer electronics. The nanoWatt XLP feature set keeps idle touch-scan current below 5 uA, and the 64-pin VQFN exposes enough I/O for backlight PWM, buzzer drive, and an I2C/SPI display interface alongside the touch matrix.
Recommended
Battery-Powered Remote Sensor Nodes
Battery-powered remote sensor nodes benefit from the PIC18F66K22T-I/MR's nanoWatt XLP technology, which delivers deep-sleep currents in the tens of nanoamps while retaining RAM and brown-out reset. The MCU wakes periodically, samples its 12-bit ADC, transmits via one of the two USART or SPI peripherals, and returns to sleep, achieving multi-year coin-cell life in metering and environmental monitoring. The 1.8 V to 5.5 V operating range covers both single-cell Li-ion and 3.6 V Li-SOCl2 chemistries without level shifting. The 64-pin VQFN integrates the full peripheral set, including the CTMU, so a single chip performs capacitance, voltage, and temperature sensing plus RF/transceiver control.
Recommended
HVAC and Home Appliance Controllers
HVAC and home appliance controllers use the PIC18F66K22T-I/MR to drive triac-controlled AC loads, read thermistor temperature sensors, run BLDC or stepper fans, and communicate on LIN or RS-485 fieldbuses. The MCU's three analog comparators support zero-cross detection for triac phase-angle firing, while its CCP/ECCP modules generate the PWM signals for variable-speed fans and valves. Two LIN-capable USARTs interface to the appliance's master controller and to user-interface subassemblies, and the 1 KB data EEPROM stores user-setpoint history across power cycles. The industrial temperature grade covers refrigerator, oven, and boiler compartments reliably.
Recommended
USB/Serial Bridging Adapters
USB-to-serial bridging adapters use the PIC18F66K22T-I/MR as the bridge MCU, leveraging its two USARTs to convert between legacy RS-232/RS-485 links and a USB host through an external transceiver or software USB bit-banging. The 64 KB Flash accommodates dual CDC class drivers, and 4 KB SRAM buffers UART-to-USB traffic without flow-control stalls. The two SPI peripherals simultaneously drive an SD card or external flash for logging, while the I2C bus interfaces to EEPROM or RTC. The 64-pin VQFN exposes enough I/O for status LEDs, push-buttons, and configuration DIP switches alongside the bridge functions, and the industrial temperature grade covers outdoor enclosures.
Recommended
Low-Cost Graphical Segment Displays
Low-cost graphical segment and small TFT displays are driven by the PIC18F66K22T-I/MR, using its two SPI channels to update a graphics controller or segment LCD driver at high refresh rates. The CCP/ECCP modules generate backlight PWM with 10-bit resolution for smooth dimming, and the 12-bit ADC reads ambient-light sensors for automatic brightness control. The CTMU enables front-panel capacitive keys behind a glass overlay. With 64 KB Flash and 4 KB SRAM, the MCU holds complete UI state machines and bitmaps for small QVGA displays, eliminating an external graphics controller and reducing BOM cost in consumer appliances.
Recommended
Recommended Products Summary
Engineering reference data for PIC18F66K22T-I/MR — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC18F66K22-I/MR | PIC18F66K22T-E/MR | PIC18F65K22T-I/MR | PIC18F65K22T-E/MR |
|---|---|---|---|---|---|
| Package | 64-pin VQFN (9x9 mm) | 64-pin VQFN (9x9 mm) - same | 64-pin VQFN (9x9 mm) - same | 64-pin VQFN (9x9 mm) - same | 64-pin VQFN (9x9 mm) - same |
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Program Memory (Flash) | 64 KB | 64 KB | 64 KB | 32 KB (-50%) | 32 KB (-50%) |
| Maximum Frequency | 64 MHz | 64 MHz | 64 MHz | 64 MHz | 64 MHz |
| SRAM | 4 KB | 4 KB | 4 KB | 2 KB (-50%) | 2 KB (-50%) |
| Data EEPROM | 1 KB | 1 KB | 1 KB | 1 KB | 1 KB |
| Operating Temperature | -40C to +85C (Industrial) | -40C to +85C (Industrial) | -40C to +125C (Extended) | -40C to +85C (Industrial) | -40C to +125C (Extended) |
| Packaging | Tape & Reel | Tray | Tape & Reel | Tape & Reel | Tape & Reel |
| Pin Compatibility | 64-pin VQFN (reference) | 100% drop-in | 100% drop-in | Footprint-compatible, I/O count reduced | Footprint-compatible, I/O count reduced |
Key Differentiators
- Tape-and-reel packaging for high-volume SMT assembly (vs PIC18F66K22-I/MR)
- Industrial vs extended temperature grade flexibility (vs PIC18F66K22T-E/MR)
- Larger Flash and RAM vs K22 sibling (vs PIC18F65K22T-I/MR)
- On-chip CTMU eliminates external touch controller (vs External capacitive touch IC designs)
Design Notes
The VQFN-64 (9x9 mm) package has an exposed thermal pad (EP) that MUST be soldered to a ground copper pour for mechanical reliability and thermal dissipation. Per Microchip application note AN246, the EP should connect to a ground plane with at least 16 thermal vias on a 0.5-1.0 mm grid. Place a 100 nF ceramic decoupling capacitor within 2 mm of every VDD and AVDD pin, plus a 10 uF bulk capacitor near the MCU. Keep the EP-to-VDD capacitance under 5 pF to avoid injected switching noise into the analog rail.
When designing nanoWatt XLP low-power applications, follow Microchip AN1307 and configure the unused peripherals to their lowest-power idle states. The PIC18F66K22T-I/MR's deep-sleep current is in the tens of nanoamps with RTCC and WDT enabled; however, leaving the ADC, comparators, or CTMU powered in sleep raises this by tens of microamps. Use the PMD (Peripheral Module Disable) registers to gate each unused peripheral's clock. Estimate (assuming IDD = 30 nA in deep sleep with RTCC, 3 V battery, 2000 mAh capacity): 2000 mAh / (30 nA * 24 h / 1e9) = approximately 2,740 years theoretical life - real-world is bounded by battery shelf life (~10 years).
Common pitfalls when bringing up the PIC18F66K22T-I/MR include: (1) forgetting to configure CONFIG words for the internal oscillator or external crystal before code execution, leaving the MCU running off the uncalibrated FRC at 4 MHz; (2) enabling the PLL with an incompatible clock source, causing the FOSC to exceed 64 MHz and triggering a brown-out; (3) assigning analog functions to pins that are remapped by the PPS (Peripheral Pin Select) module without unlocking IOLOCK; and (4) sharing ICSP lines (PGC/PGD on RB6/RB7) with external pull-ups that exceed 10 kohm, which prevents in-circuit programming. Always read CONFIG settings into MPLAB X before debugging.
Place the ICSP connector (PGC/PGD/RESET/VPP/GND) at the board edge for in-circuit programming access, with each signal routed within 100 mm of the MCU. Keep analog inputs (AN0-AN15) physically separated from digital switching traces, with the AVSS pin returning to a quiet ground island joined to the digital ground at a single point. For capacitive-touch PCB layouts, use Microchip AN1258: route each electrode with a hatched or solid guard ring driven by the same CTMU current source return to suppress stray capacitance, and ensure the touch electrode's ground reference is the local chassis, not earth.
Compliance Information
RoHS and REACH compliant per Microchip product page. Industrial temperature grade; not AEC-Q100 qualified - use PIC18F66K22-E/MR series for AEC-Q100 automotive requirements. Lead-free and halogen-free per Microchip Material Declaration.
