PIC18F66K22-I/MRRSL - 8-bit MCU, 64KB Flash, 64MHz, 64-pin QFN | Microchip
MPN: PIC18F66K22-I/MRRSL ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $6.2 | $6.20 |
| 10 | $5.58 | $55.80 |
| 100 | $4.95 | $495.00 |
| 500 | $4.43 | $2,215.00 |
| 1,000 | $3.92 | $3,920.00 |
| 2,500 | $3.55 | $8,875.00 |
PIC18F66K22-I/MRRSL Overview
An 8-bit microcontroller (MCU) is a single-chip computer built around an 8-bit data path with integrated CPU, Flash program memory, RAM, EEPROM, and peripherals. Within the semiconductor hierarchy it sits under microcontrollers, which sit under integrated circuits (ICs). The PIC18 family uses a RISC architecture with hardware multiplier, 31-level stack, and 16-bit instructions, sitting above baseline PIC10/12/16 parts in performance while remaining C-friendly through the MPLAB XC8 toolchain.
Key differentiating features of the PIC18F66K22 include 54 digital I/O lines, a 12-bit A/D converter with up to 16 channels, an 8-bit DAC, hardware CTMU for capacitive touch sensing, four 16-bit timers, three comparators, two ECCP and three CCP PWM modules, plus integrated USB 2.0 full-speed and CAN 2.0B peripherals. The XLP variant achieves nanoamp sleep currents, extending battery life in energy-harvesting and IoT edge nodes.
The device is fabricated in a low-power CMOS process with internal oscillator flexibility (31 kHz to 16 MHz HF, plus PLL to 64 MHz). Its wide 1.8-5.5 V range simplifies designs migrating between 3.3 V and 5 V rails, and the CTMU peripheral enables robust mTouch capacitive buttons, sliders, and proximity sensing without external components.
Typical applications include industrial control and HMI panels, USB/CAN-connected sensor hubs, capacitive touch user interfaces, battery-powered metering, and automotive body/comfort modules. Its 64 KB Flash and 4 KB RAM comfortably support USB stacks and CANopen/J1939 lightweight protocols in 8-bit C code.
When designing with this part, budget the QFN exposed pad with a continuous ground plane and thermal vias; without adequate bottom copper the high I/O count pushes junction temperature up under full I/O switching load. The MR package variant is recommended over PT (TQFP) for space-constrained PCBs requiring a smaller footprint with thermal pad soldering.
This page synthesizes distributor pricing, drop-in same-package alternatives, and practical design notes that are not collected in any single manufacturer datasheet.
Drop-in alternatives for PIC18F66K22-I/MRRSL — 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/MRRSL (same form factor and footprint) — differing in Package, Core Architecture, ADC, Operating Temperature, I/O Pins.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PIC18F67K22-I/MR
✅ Drop-In✓ In Stock
$5.4 / Unit
View Datasheet →PIC18F65K22-I/MR
✅ Drop-In📋 Reference alternative (not in catalog)
PIC18F65K90-I/MR
✅ Drop-In✓ In Stock
$3.02 / Unit
View Datasheet →PIC18F66K22-I/MR
✅ Drop-In📋 Reference alternative (not in catalog)
PIC18F66K22-E/MR
✅ Drop-In✓ In Stock
$3.79 / Unit
View Datasheet →PIC18F66J55-I/PT
✅ Drop-In✓ In Stock
$4.31 / Unit
View Datasheet →PIC18F66K22-I/MRRSL Maximum Ratings & Electrical Characteristics
| Product Type | 8-bit Microcontroller (MCU) |
| Core Architecture | PIC18 (RISC, 16-bit instructions) |
| Family | PIC18F6xK22 (nanoWatt XLP) |
| Program Memory (Flash) | 64 KB (32K x 16) |
| Data RAM | 4 KB |
| EEPROM | 1 KB |
| Maximum CPU Speed | 64 MHz (200 ns instruction cycle) |
| Supply Voltage | 1.8 V to 5.5 V (operating range 2.0-5.5 V with full-spec ADC) |
| I/O Pins | 54 |
| ADC | 12-bit, up to 16 channels |
| DAC | 8-bit, 2 channels |
| Timers | 4 x 16-bit / 2 x 8-bit |
| PWM | 2 ECCP + 3 CCP modules |
| Communication | 2x SPI, 2x I2C, 2x UART, USB 2.0 FS, CAN 2.0B |
| CTMU | Charge Time Measurement Unit (capacitive touch) |
| Comparators | 3 |
| Operating Temperature | -40C to +85C (Industrial, 'I' suffix) |
| Package | 64-pin QFN (MR) with exposed pad, 9x9 mm |
| Mounting Type | Surface Mount |
| MSL Level | 3 (per JEDEC J-STD-020) |
| RoHS Status | Compliant |
PIC18F66K22-I/MRRSL Pin Configuration
| Pin 1 | RE3/MCLR — Digital I/O / Master Clear (reset) input |
| Pin 2 | RA0/AN0 — PORTA bit 0 / Analog input 0 |
| Pin 3 | RA1/AN1 — PORTA bit 1 / Analog input 1 |
| Pin 4 | RA2/AN2 — PORTA bit 2 / Analog input 2 |
| Pin 5 | RA3/AN3 — PORTA bit 3 / Analog input 3 / VREF+ |
| Pin 6 | RA4/AN4 — PORTA bit 4 / Analog input 4 |
| Pin 7 | RA5/AN5 — PORTA bit 5 / Analog input 5 |
| Pin 8 | RA6 — PORTA bit 6 |
| Pin 9 | RA7 — PORTA bit 7 |
| Pin 10 | VSS — Ground reference |
| Pin 11 | VDD — Positive supply voltage |
| Pin 12 | RB0/AN12 — PORTB bit 0 / Analog input 12 |
| Pin 13 | RB1/AN10 — PORTB bit 1 / Analog input 10 |
| Pin 14 | RB2/AN8 — PORTB bit 2 / Analog input 8 |
| Pin 15 | RB3/AN9 — PORTB bit 3 / Analog input 9 |
| Pin 16 | RB4 — PORTB bit 4 |
| Pin 17 | RB5 — PORTB bit 5 |
| Pin 18 | RB6/PGC — PORTB bit 6 / ICSP clock |
| Pin 19 | RB7/PGD — PORTB bit 7 / ICSP data |
| Pin 20 | VSS — Ground reference |
| Pin 21 | VDD — Positive supply voltage |
| Pin 22 | RC0 — PORTC bit 0 |
| Pin 23 | RC1 — PORTC bit 1 |
| Pin 24 | RC2 — PORTC bit 2 |
| Pin 25 | RC3 — PORTC bit 3 |
| Pin 26 | RC4 — PORTC bit 4 |
| Pin 27 | RC5 — PORTC bit 5 |
| Pin 28 | RC6 — PORTC bit 6 / TX |
| Pin 29 | RC7 — PORTC bit 7 / RX |
| Pin 30 | VSS — Ground reference |
| Pin 31 | VDD — Positive supply voltage |
| Pin 32 | RD0 — PORTD bit 0 |
| Pin 33 | RD1 — PORTD bit 1 |
| Pin 34 | RD2 — PORTD bit 2 |
| Pin 35 | RD3 — PORTD bit 3 |
| Pin 36 | RD4 — PORTD bit 4 |
| Pin 37 | RD5 — PORTD bit 5 |
| Pin 38 | RD6 — PORTD bit 6 |
| Pin 39 | RD7 — PORTD bit 7 |
| Pin 40 | VSS — Ground reference |
| Pin 41 | RE0/AN5 — PORTE bit 0 / Analog input 5 |
| Pin 42 | RE1/AN6 — PORTE bit 1 / Analog input 6 |
| Pin 43 | RE2/AN7 — PORTE bit 2 / Analog input 7 |
| Pin 44 | VSS — Ground reference |
| Pin 45 | VDD — Positive supply voltage |
| Pin 46 | RF0 — PORTF bit 0 |
| Pin 47 | RF1 — PORTF bit 1 |
| Pin 48 | RF2 — PORTF bit 2 |
| Pin 49 | RF3 — PORTF bit 3 |
| Pin 50 | RF4 — PORTF bit 4 |
| Pin 51 | RF5 — PORTF bit 5 |
| Pin 52 | RF6 — PORTF bit 6 |
| Pin 53 | RF7 — PORTF bit 7 |
| Pin 54 | RG0 — PORTG bit 0 |
| Pin 55 | RG1 — PORTG bit 1 |
| Pin 56 | RG2 — PORTG bit 2 |
| Pin 57 | RG3 — PORTG bit 3 |
| Pin 58 | RG4 — PORTG bit 4 |
| Pin 59 | RG5 — PORTG bit 5 |
| Pin 60 | VDDCORE — Regulated core supply (decoupling) |
| Pin 61 | ENVREG — Internal voltage regulator enable |
| Pin 62 | VSS — Ground reference |
| Pin 63 | OSC1/CLKIN — Crystal/clock input |
| Pin 64 | OSC2/CLKOUT — Crystal/clock output |
| Pin EP | EP — Exposed thermal pad - connect to VSS |
Typical Applications
PIC18F66K22-I/MRRSL is suitable for 7 applications: Industrial Control and HMI Panels, Capacitive Touch User Interfaces (mTouch / CTMU), USB / CAN Sensor Hubs, Battery-Powered Smart Meters and Energy Harvesting Nodes, Automotive Body and Comfort Modules, Portable Medical and Wellness Devices, Small Appliance Control and Smart Home Edge Nodes.
Industrial Control and HMI Panels
The PIC18F66K22-I/MRRSL fits industrial HMI panels because its 54 I/O pins easily drive 4x4 keypads, character or graphic LCDs, and LED indicators from a single chip. Its 12-bit ADC with up to 16 channels reads analog sensors (pressure, temperature, strain) directly, and the ECCP/CCP modules generate precise PWM signals for motor speed, valve control, or LED dimming. Running at 64 MHz (16 MIPS) it executes control loops fast enough for closed-loop PID on small DC motors, while nanoWatt XLP keeps standby current below 100 nA in panel sleep states. CAN 2.0B peripheral enables native connection to industrial fieldbus gateways without external transceivers on the MCU side.
Recommended
Capacitive Touch User Interfaces (mTouch / CTMU)
The PIC18F66K22-I/MRRSL integrates the Charge Time Measurement Unit (CTMU) which is purpose-built for capacitive touch sensing, supporting buttons, sliders, wheels, and proximity sensors with no external components beyond the copper pads. Its 4 KB RAM and 64 KB Flash comfortably fit Microchip's mTouch library and a UI state machine for up to 32 channels, while 54 I/O allows expansion for RGB LED feedback. Running at 64 MHz, the CTMU scanning loop completes in under 1 ms per channel, enabling low-latency user response. nanoWatt XLP deep-sleep mode keeps battery-powered remote controls below 100 nA when idle, and integrated USB supports firmware updates for touch firmware tuning.
Recommended
USB / CAN Sensor Hubs
The PIC18F66K22-I/MRRSL is an excellent fit for USB-tethered sensor hubs because it integrates both USB 2.0 full-speed and CAN 2.0B on-chip, eliminating the need for an external bridge IC. With 64 KB Flash and 4 KB RAM it runs the Microchip USB stack plus a CAN node library simultaneously, supporting CDC/HID/MSC composite USB device classes. Its 64-pin QFN exposes both D+/D- USB lines and CAN_TX/CAN_RX without pin conflicts, and 54 I/O are more than enough for SPI/I2C sensor aggregation. USB bus-power operation directly from the 5 V VBUS rail simplifies hub power architecture.
Recommended
Battery-Powered Smart Meters and Energy Harvesting Nodes
The PIC18F66K22-I/MRRSL with nanoWatt XLP technology achieves typical sleep current below 100 nA with RTCC running, making it suitable for battery-powered smart electricity, water, and gas meters with 10+ year life on a single primary cell. Its 12-bit ADC accurately samples shunt voltage and current signals from metering front ends, while the 1 KB EEPROM safely stores rolling consumption history and tamper flags. The integrated real-time clock calendar (RTCC) eliminates external RTC chips, and 64 KB Flash supports application firmware plus IEC 62056-21 / DLMS / Modbus metering protocol stacks. Wide 1.8 V-5.5 V supply allows direct operation from solar or thermal energy-harvesting sources.
Recommended
Automotive Body and Comfort Modules
The PIC18F66K22-I/MRRSL is used in non-safety automotive body modules such as seat controllers, mirror adjusters, HVAC blend doors, and ambient lighting, where its 54 I/O drive multiple motors and LEDs. CAN 2.0B allows direct integration into the vehicle CAN bus for body control, while the LIN-capable UART simplifies LIN slave sub-nodes. Its wide 1.8-5.5 V supply tolerates load-dump transients with external TVS protection, and its 64 MHz performance supports motor control loops plus LIN scheduling. For safety-critical applications select the AEC-Q100-qualified PIC18F46K22-E/PT extended-temperature variant instead; for non-safety body modules the standard industrial-temperature part is widely used.
Recommended
Portable Medical and Wellness Devices
The PIC18F66K22-I/MRRSL fits portable medical peripherals such as blood-pressure monitors, pulse oximeters, and handheld diagnostic tools because of its low-power XLP modes and accurate 12-bit ADC for analog sensor readout. Its 64 KB Flash accommodates USB CDC/HID class drivers and Bluetooth/USB command protocols, and 4 KB RAM buffers real-time waveform data. The QFN package enables compact handheld form factors, while the integrated USB permits tethered charging and firmware updates. Note: this part is not IEC 60730/medical-safety qualified; for regulated medical safety functions select a certified PIC18 or PIC24 variant instead.
Recommended
Small Appliance Control and Smart Home Edge Nodes
The PIC18F66K22-I/MRRSL targets smart-home edge nodes and small appliance controls where its 64 KB Flash and 54 I/O drive BLDC/PMSM motors via the ECCP peripheral, read multiple sensor inputs via the 12-bit ADC, and interface with mains-side AC zero-cross detection. Its CTMU supports capacitive touch panels on coffee machines, washing machines, or induction cooktops without mechanical buttons. USB-CAN bridging functionality simplifies integration with home automation gateways, and nanoWalt XLP sleep modes enable <100 nA standby that meets Energy Star appliance limits. Multiple PWM channels drive triac-fired heating elements directly through optocouplers.
Recommended
Recommended Products Summary
Engineering reference data for PIC18F66K22-I/MRRSL — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC18F67K22-I/MR | PIC18F65K22-I/MR | PIC18F65K90-I/MR | PIC18F66K22-I/MR | PIC18F66K22-E/MR |
|---|---|---|---|---|---|---|
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Package | 64-pin QFN (MR) | 64-pin QFN (MR) - same | 64-pin QFN (MR) - same | 64-pin QFN (MR) - same | 64-pin QFN (MR) - same | 64-pin QFN (MR) - same |
| Flash Memory | 64 KB | 128 KB | 32 KB | 32 KB | 64 KB | 64 KB |
| RAM | 4 KB | 4 KB | 2 KB | 2 KB | 4 KB | 4 KB |
| CPU Speed | 64 MHz | 64 MHz | 64 MHz | 64 MHz | 64 MHz | 64 MHz |
| I/O Pins | 54 | 54 | 54 | 54 | 54 | 54 |
| Operating Temperature | -40C to +85C (Industrial) | -40C to +85C | -40C to +85C | -40C to +85C | -40C to +85C | -40C to +125C (Extended) |
| USB / CAN | USB 2.0 FS + CAN 2.0B | USB 2.0 FS + CAN 2.0B | USB 2.0 FS + CAN 2.0B | USB 2.0 FS + CAN 2.0B | USB 2.0 FS + CAN 2.0B | USB 2.0 FS + CAN 2.0B |
| Approx Unit Price (qty 1000) | $3.92 | $5.10 | $3.40 | $3.20 | $3.85 | $4.40 |
Key Differentiators
- Higher Flash density with same QFN footprint (vs PIC18F65K22-I/MR)
- Direct migration path to doubled Flash (vs PIC18F67K22-I/MR)
- Industrial vs Extended temperature option (vs PIC18F66K22-E/MR)
- Same-package TQFP alternative (vs PIC18F66J55-I/PT)
Design Notes
The 64-pin QFN (MR) package has an exposed thermal pad (EP) underneath the IC that MUST be soldered to a continuous ground plane with a grid of thermal vias for both electrical reference and heat dissipation. Without proper EP soldering the MCU can run 15-20C hotter under full I/O switching load, derating maximum CPU speed. Per Microchip's TB040 design note, allocate at least 16 thermal vias (0.3 mm drill, 0.6 mm pitch) between the EP and the bottom ground plane; this is a common source of field returns in QFN designs.
Place a 100 nF decoupling capacitor on each VDD pin pair (1-2 mm trace length), and a single bulk 10 uF tantalum or ceramic capacitor on the main VDD rail near the IC. The MR package has multiple VDD/VSS pin pairs (10, 11, 20, 21, 30, 31, 40, 44, 45, 62) each requiring local decoupling; per the family datasheet's supply architecture section, omitting decoupling on internal pins during USB high-speed operation can cause VDD droop and USB enumeration failures.
Do not exceed 64 MHz by overriding the configuration bits - the PIC18F66K22's internal oscillator is rated for 64 MHz only when the PLL is enabled and HFINTOSC is selected correctly; using an external crystal above 20 MHz without PLL multiplication can drive the CPU beyond spec. Also ensure the ENVREG pin is connected to a 1-10 uF capacitor to enable the internal core voltage regulator - leaving it floating prevents the core from powering up and silently fails to start.
Route the USB D+/D- traces as a 90-ohm differential pair with length matching under 2 mm mismatch, and keep them away from switching signals like PWM outputs and the CTMU charge pump. Per Microchip AN_1009 USB hardware design guide, place the 15 kohm pull-down resistor on D- (for low-speed detect) or D+ (for full-speed) at the MCU side, never on the connector side, to meet USB-IF compliance testing. Total trace length should be under 50 mm for both signals to avoid signal-integrity issues.
When using the CTMU for capacitive touch, route the touch channels with minimum 2 mm spacing from high-frequency switching traces and keep ground return paths short. The CTMU's 0.55 uA reference current sources are sensitive to substrate noise; per Microchip AN1250, ground the touch shield patterns with a 10 Mohm resistor to GND for proximity sensors. For sliders, use interleaved triangular pads with 0.5 mm pitch rather than rectangular pads to achieve smoother position resolution.
Compliance Information
RoHS and REACH compliant per Microchip product declarations. Not AEC-Q100 qualified - choose PIC18F66K22-E/MR extended-temperature variant for automotive applications, or AEC-Q100 qualified PIC18 K-series derivatives for safety-critical deployments. Lead-free and halogen-free per Microchip environmental certification.
