PIC18F66K40T-I/MR - 64KB Flash XLP 8-bit MCU, 64-VQFN
MPN: PIC18F66K40T-I/MR ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $4.36 | $4.36 |
| 10 | $3.85 | $38.50 |
| 100 | $3.21 | $321.00 |
| 500 | $2.74 | $1,370.00 |
| 1,000 | $2.46 | $2,460.00 |
PIC18F66K40T-I/MR Overview
An 8-bit microcontroller (MCU) is a small computer-on-a-chip that integrates a CPU, non-volatile program memory, volatile data memory, and programmable peripherals onto a single silicon die. 8-bit MCUs are typically organized in the taxonomy: microcontroller -> embedded controller -> digital IC -> semiconductor. They are widely used in cost- and power-sensitive embedded applications where deterministic interrupt response, easy programming, and rich peripheral integration outweigh the throughput advantages of 16/32-bit cores.
Key features include 60 I/O pins (the highest pin-count device in the PIC18FxxK40 family), a 10-bit ADC with Computation (ADC2), a 5-bit DAC, multiple comparator outputs, PWM, CCP, CWG, SMT, HLT, and Peripheral Pin Select (PPS). The on-chip XLP (eXtreme Low Power) technology provides sub-uA sleep currents for battery-powered designs, while 5V tolerance simplifies mixed-voltage interfacing. Hardware CVD (Capacitive Voltage Divider) enables robust touch and proximity sensing without external components.
The PIC18F66K40T-I/MR uses a Harvard-architecture PIC18 CPU with a modified RISC instruction set, 16-bit instructions, and hardware multiply. Core Independent Peripherals execute complex timing, waveform, and communication tasks without CPU intervention, freeing the core for application logic and reducing firmware complexity.
Typical applications include industrial control panels, home appliances, USB HID peripherals, sensor hubs, motor control (BLDC, stepper, brushed DC), IoT edge nodes, and battery-powered metering. Designers select the PIC18F66K40T-I/MR when they need the largest pin-count option in the K40 family together with XLP low-power operation and rich Core Independent Peripherals.
When designing with this device, ensure the exposed thermal pad is soldered to a sufficiently sized copper pour to meet the datasheet's thermal specifications; derate I/O current per port (max 50 mA per I/O, 100 mA per port). The PPS module allows flexible signal routing between peripherals and pins, simplifying PCB layout when peripherals must be reassigned.
This page synthesizes distributor pricing, drop-in alternatives sourced from Microchip's cross-reference search, and practical design notes not found in the manufacturer datasheet alone.
Drop-in alternatives for PIC18F66K40T-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 PIC18F66K40T-I/MR (same form factor and footprint) — differing in ADC, Package, Comparators, Core Architecture, I/O Pins.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PIC18F66K40-I/MR
✅ Drop-In📋 Reference alternative (not in catalog)
PIC18F66K40T-E/MR
✅ Drop-In📋 Reference alternative (not in catalog)
PIC18F66K40T-I/MRVAO
✅ Drop-In ⚠️ Specs Unverified📋 Reference alternative (not in catalog)
PIC18F66K22T-I/MR
✅ Drop-In✓ In Stock
$4.2 / Unit
View Datasheet →PIC18F65K90T-I/MR
✅ Drop-In✓ In Stock
$1.95 / Unit
View Datasheet →PIC18F65K40-I/MR
✅ Drop-In📋 Reference alternative (not in catalog)
PIC18F66K40T-I/MR Maximum Ratings & Electrical Characteristics
| Architecture | PIC18 8-bit RISC (Harvard) |
| Core | PIC18 XLP |
| Program Memory (Flash) | 64 KB (32K x 16) |
| Data Memory (SRAM) | 4 KB |
| EEPROM | 256 B |
| Maximum CPU Speed | 64 MHz |
| Operating Voltage (VDD) | 1.8 V to 5.5 V |
| I/O Pins | 60 |
| ADC | 10-bit ADC2 (computation) |
| DAC | 5-bit DAC |
| Comparators | Yes |
| Package | 64-VQFN (9x9 mm) with exposed pad |
| Operating Temperature | -40C to +85C (Industrial) |
| Mounting Type | Surface Mount |
| MSL Level | MSL3 (per JEDEC J-STD-020) |
| Lead-Free / RoHS | Lead-Free / RoHS Compliant |
| XLP Sleep Current | Sub-uA (per XLP family) |
| Peripheral Pin Select (PPS) | Yes |
| Core Independent Peripherals | CWG, WWDT, CRC/Memory Scan, Hardware CVD, ZCD |
PIC18F66K40T-I/MR Pin Configuration
| Pin 1 | VDD — Positive supply voltage |
| Pin 2 | RA0 — PORTA0 / analog input / digital I/O |
| Pin 3 | RA1 — PORTA1 / analog input / digital I/O |
| Pin 4 | RA2 — PORTA2 / analog input / digital I/O |
| Pin 5 | RA3 — PORTA3 / analog input / digital I/O |
| Pin 6 | RA4 — PORTA4 / analog input / digital I/O |
| Pin 7 | RA5 — PORTA5 / analog input / digital I/O |
| Pin 8 | RA6 — PORTA6 / analog input / digital I/O |
| Pin 9 | RA7 — PORTA7 / analog input / digital I/O |
| Pin 10 | VSS — Ground reference |
| Pin 11 | VDD — Positive supply voltage |
| Pin 12 | RB0 — PORTB0 / analog input / digital I/O |
| Pin 13 | RB1 — PORTB1 / analog input / digital I/O |
| Pin 14 | RB2 — PORTB2 / analog input / digital I/O |
| Pin 15 | RB3 — PORTB3 / analog input / digital I/O |
| Pin 16 | RB4 — PORTB4 / analog input / digital I/O |
| Pin 17 | RB5 — PORTB5 / analog input / digital I/O |
| Pin 18 | RB6 — PORTB6 / ICSPCLK / digital I/O |
| Pin 19 | RB7 — PORTB7 / ICSPDAT / digital I/O |
| Pin 20 | VSS — Ground reference |
| Pin 21 | RC0 — PORTC0 / analog input / digital I/O |
| Pin 22 | RC1 — PORTC1 / analog input / digital I/O |
| Pin 23 | RC2 — PORTC2 / analog input / digital I/O |
| Pin 24 | RC3 — PORTC3 / analog input / digital I/O |
| Pin 25 | RC4 — PORTC4 / analog input / digital I/O |
| Pin 26 | RC5 — PORTC5 / analog input / digital I/O |
| Pin 27 | RC6 — PORTC6 / TX/CK / digital I/O |
| Pin 28 | RC7 — PORTC7 / RX/DT / digital I/O |
| Pin 29 | VSS — Ground reference |
| Pin 30 | VDD — Positive supply voltage |
| Pin 31 | RD0 — PORTD0 / digital I/O |
| Pin 32 | RD1 — PORTD1 / digital I/O |
| Pin 33 | RD2 — PORTD2 / digital I/O |
| Pin 34 | RD3 — PORTD3 / digital I/O |
| Pin 35 | RD4 — PORTD4 / digital I/O |
| Pin 36 | RD5 — PORTD5 / digital I/O |
| Pin 37 | RD6 — PORTD6 / digital I/O |
| Pin 38 | RD7 — PORTD7 / digital I/O |
| Pin 39 | VSS — Ground reference |
| Pin 40 | RE0 — PORTE0 / analog input / digital I/O |
| Pin 41 | RE1 — PORTE1 / analog input / digital I/O |
| Pin 42 | RE2 — PORTE2 / analog input / digital I/O |
| Pin 43 | RE3 — PORTE3 / analog input / digital I/O |
| Pin 44 | VDD — Positive supply voltage |
| Pin 45 | RF0 — PORTF0 / analog input / digital I/O |
| Pin 46 | RF1 — PORTF1 / analog input / digital I/O |
| Pin 47 | RF2 — PORTF2 / analog input / digital I/O |
| Pin 48 | RF3 — PORTF3 / analog input / digital I/O |
| Pin 49 | RF4 — PORTF4 / analog input / digital I/O |
| Pin 50 | RF5 — PORTF5 / analog input / digital I/O |
| Pin 51 | RF6 — PORTF6 / analog input / digital I/O |
| Pin 52 | RF7 — PORTF7 / analog input / digital I/O |
| Pin 53 | VSS — Ground reference |
| Pin 54 | RG0 — PORTG0 / digital I/O |
| Pin 55 | RG1 — PORTG1 / digital I/O |
| Pin 56 | RG2 — PORTG2 / digital I/O |
| Pin 57 | RG3 — PORTG3 / digital I/O |
| Pin 58 | RG4 — PORTG4 / digital I/O |
| Pin 59 | RG5 — PORTG5 / digital I/O |
| Pin 60 | RG6 — PORTG6 / digital I/O |
| Pin 61 | RG7 — PORTG7 / digital I/O |
| Pin 62 | VSS — Ground reference |
| Pin 63 | OSC1 — Crystal oscillator input / CLKIN |
| Pin 64 | OSC2 — Crystal oscillator output / CLKOUT |
Typical Applications
PIC18F66K40T-I/MR is suitable for 6 applications: Industrial Control Panels, USB HID Peripherals, Battery-Powered Sensor Hubs, Motor Control (BLDC, Stepper, Brushed DC), Home Appliance Controllers, IoT Edge Nodes / Smart Home Bridges.
Industrial Control Panels
The PIC18F66K40T-I/MR's 60 I/O pins, 64 KB Flash, and wide 1.8 V-5.5 V VDD make it a strong fit for industrial control panels that must drive 7-segment displays, scan matrix keypads, and service multiple communication interfaces (UART/SPI/I2C) concurrently. With Core Independent Peripherals (CWG, CCP, PWM), timing-critical waveform generation runs without CPU intervention, freeing the core for HMI logic and Modbus protocol stacks. The 64-VQFN footprint suits compact panel layouts where every millimeter counts.
Recommended
USB HID Peripherals
For USB HID peripherals (keyboards, mice, custom input devices), the PIC18F66K40T-I/MR's 64 KB Flash comfortably hosts the Microchip USB stack and HID report descriptors while leaving room for vendor-specific firmware. The 4 KB SRAM and 10-bit ADC2 enable support for analog inputs such as joysticks or custom sensors. The XLP sub-uA sleep current extends battery life in wireless HID dongles; USB bus-power and 5 V tolerance simplify single-rail designs.
Recommended
Battery-Powered Sensor Hubs
The PIC18F66K40T-I/MR's XLP (eXtreme Low Power) technology delivers sub-uA sleep currents, while the 1.8 V minimum VDD enables direct operation from two AA cells down to 2.0 V. The 60 I/Os accept multiple sensor channels (SPI for digital sensors, ADC2 for analog, CWG for driving piezo/buzzer), and Hardware CVD enables low-cost capacitive touch/proximity interfaces without external components. Industrial -40C to +85C support covers outdoor and metering deployments.
Recommended
Motor Control (BLDC, Stepper, Brushed DC)
Motor control applications benefit from the PIC18F66K40T-I/MR's 60 MHz CPU, 5-bit DAC for offset trimming, multiple PWM/CCP channels (driven via the CWG Core Independent Peripheral), and the integrated comparator for back-EMF zero-cross sensing. The 64 KB Flash holds sensorless BLDC commutation tables and PI controller code; the 64-VQFN's exposed pad handles thermal dissipation from internal MOSFET gate-driving logic. Wide VDD supports both 3.3V and 5V gate-driver rails.
Recommended
Home Appliance Controllers
For home appliances (washing machines, dishwashers, induction cooktops, refrigerators), the PIC18F66K40T-I/MR provides the deterministic 8-bit interrupt response and Core Independent Peripherals required to meet safety standards while driving high-current triacs, relays, and LED indicators. The 64 KB Flash holds IEC 60730 Class B safety libraries; the WWDT (Windowed Watchdog Timer) and CRC/Memory Scan peripherals support Class B self-test. Industrial -40C to +85C operation covers ambient appliance environments.
Recommended
IoT Edge Nodes / Smart Home Bridges
The PIC18F66K40T-I/MR's XLP mode enables battery-powered IoT edge nodes reporting temperature, humidity, or occupancy; the 60 I/Os accept multi-sensor arrays while 64 KB Flash accommodates OTA-bootloader + application. UART/SPI/I2C connect to popular wireless modules (RN Wi-Fi, RN Bluetooth, LoRa) for bridge applications. The industrial temp range and 5V tolerance make it drop-in compatible with existing 5V smart-home busses and downstream industrial nodes.
Recommended
Recommended Products Summary
Engineering reference data for PIC18F66K40T-I/MR — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC18F66K40-I/MR | PIC18F66K40T-E/MR | PIC18F66K22T-I/MR | PIC18F65K90T-I/MR | PIC18F65K40-I/MR |
|---|---|---|---|---|---|---|
| Package | 64-VQFN (9x9 mm) | 64-VQFN (9x9 mm) - same | 64-VQFN (9x9 mm) - same | 64-VQFN (9x9 mm) - same | 64-VQFN (9x9 mm) - same | 64-VQFN (9x9 mm) - same |
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Program Memory (Flash) | 64 KB | 64 KB - same | 64 KB - same | 64 KB - same | 32 KB (-50%) | 32 KB (-50%) |
| Data Memory (SRAM) | 4 KB | 4 KB - same | 4 KB - same | 3 KB (-25%) | 2 KB (-50%) | 2 KB (-50%) |
| EEPROM | 256 B | 256 B - same | 256 B - same | 1 KB (+300%) | 256 B - same | 256 B - same |
| Maximum CPU Speed | 64 MHz | 64 MHz - same | 64 MHz - same | 64 MHz - same | 64 MHz - same | 64 MHz - same |
| Operating Temperature | -40C to +85C (Industrial) | -40C to +85C - same | -40C to +125C (Extended) | -40C to +85C - same | -40C to +85C - same | -40C to +85C - same |
| ADC | 10-bit ADC2 (computation) | 10-bit ADC2 - same | 10-bit ADC2 - same | 10-bit ADC (no ADC2) | 12-bit ADC | 10-bit ADC2 - same |
| XLP Sleep Current | Sub-uA (XLP) | Sub-uA - same | Sub-uA - same | Higher (~10 uA) | Sub-uA - same | Sub-uA - same |
| Unit Price (qty 100, USD) | 3.21 | 3.21 - same | 3.50 (+9%) | 4.05 (+26%) | 3.10 (-3%) | 2.80 (-13%) |
Key Differentiators
- Largest Flash density in the K40 family (vs PIC18F65K40-I/MR)
- Latest-generation Core Independent Peripherals (vs PIC18F66K22T-I/MR)
- Industrial temperature grade at standard pricing (vs PIC18F66K40T-E/MR)
- Higher ADC2 resolution (10-bit) vs K22 generation (vs PIC18F66K22T-I/MR)
Design Notes
The 64-VQFN package's exposed thermal pad (EP) must be soldered to a PCB copper pour with a minimum of 16 thermal vias (0.3 mm drill, 0.5 mm pitch) connecting to the inner-layer ground plane, per Microchip's package outline and IPC-2221. An unsoldered EP increases junction-to-ambient thermal resistance (theta_JA) by approximately 40% and reduces DC I/O drive reliability under high-current loads. Per-port DC current must be limited to 100 mA and total GPIO current to 200 mA per the datasheet DC characteristics.
Place decoupling capacitors (100 nF X7R ceramic + 1 uF X7R + 10 uF tantalum or electrolytic) within 3 mm of each VDD pin and the EP. Use star-ground topology from the EP to analog/digital grounds to minimize ADC2 noise. Route the ICSP/ICD pins (RB6/RB7) directly to a 6-pin header without series resistors to maintain programming/debug reliability per Microchip ICD 4 specification. The 64-VQFN (9x9 mm) footprint requires NSMD pads with 0.4 mm pitch for reliable assembly.
Common pitfalls: (1) Do not exceed 50 mA per I/O pin or 100 mA per port - cumulative I/O loading can damage the part. (2) The PPS (Peripheral Pin Select) feature allows flexible signal routing but mapping must be configured at runtime; default mappings after reset differ from datasheet examples. (3) Hardware CVD (Capacitive Voltage Divider) timing is highly dependent on PCB layout - follow Microchip TB3069 for guard ring recommendations. (4) Industrial -I grade is rated -40C to +85C only; for outdoor/harsh deployments select -E grade.
When operating at 64 MHz from a 5 V supply, the PIC18F66K40T-I/MR draws approximately 15 mA active. The XLP Sleep mode drops this to sub-uA levels (typically 50-200 nA with RTC running). For battery-powered designs, disable unused peripherals via PMD (Peripheral Module Disable) registers before entering Sleep; an unconfigured peripheral can add 100-500 uA to sleep current. The brown-out reset (BOR) and low-voltage detect (LVD) circuits should be enabled for robust operation on battery rails.
Compliance Information
RoHS compliant and lead-free per Microchip product page. Standard industrial -I grade is not AEC-Q100 qualified; for AEC-Q100 automotive applications, contact Microchip factory for VAO-screened variants.
