PIC18F66K22T-I/PT - 64KB Flash 8-bit XLP MCU TQFP-64 | Microchip
MPN: PIC18F66K22T-I/PT ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $4.2 | $4.20 |
| 10 | $3.95 | $39.50 |
| 100 | $3.62 | $362.00 |
| 500 | $3.2 | $1,600.00 |
| 1,000 | $2.95 | $2,950.00 |
PIC18F66K22T-I/PT Overview
A microcontroller (MCU) is a single-chip computer integrating a CPU core, program and data memory, peripherals, and I/O. The PIC18F family is Microchip's high-performance 8-bit tier and sits within the broader taxonomy: 8-bit MCU -> PIC MCU -> microcontroller -> embedded processor -> semiconductor. nanoWalt XLP technology adds ultra-low-power sleep and run modes that extend battery life in energy-harvested or coin-cell designs.
Key features include 54 digital I/O pins, a 12-bit A/D converter with up to 16 channels, two analog comparators, an onboard Charge Time Measurement Unit (CTMU) that simplifies capacitive touch and precise timing applications, multiple Enhanced USART, SPI and I2C peripherals, seven 8/16-bit timers, and a 5-bit DAC. The device operates across 1.8 V to 5.5 V (depending on configuration) and supports industrial temperature grades from -40C to +85C.
Architecturally, the PIC18F66K22 uses a 16-bit modified Harvard structure with separate program Flash and data SRAM buses, enabling simultaneous instruction fetch and operand access. The integrated CTMU provides constant-current source/sink capabilities that, paired with the ADC, enable accurate time-of-flight measurement for distance sensing or capacitive touch user interfaces without external components.
Typical applications span industrial control panels, building automation, sensor hubs, low-power remote keyless entry, medical instrumentation, USB/HID peripherals, and battery-powered IoT nodes. The combination of XLP deep-sleep current in the nanoamp range, generous I/O count, and the integrated CTMU makes it attractive for power-constrained edge nodes.
Designers should evaluate the supplied 1.8 V/3.3 V/5 V operating modes, route AVdd and AVss pins cleanly to preserve ADC SNR, and follow Microchip TB0763 layout guidance for nanoWatt XLP decoupling. The CTMU requires careful calibration against a stable internal or external time base.
This page synthesizes distributor pricing, drop-in alternatives, and practical design notes not found in the manufacturer datasheet - giving embedded engineers a faster path to BOM validation and second-source qualification.
Drop-in alternatives for PIC18F66K22T-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 PIC18F66K22T-I/PT (same form factor and footprint) — differing in Package, I/O Pins, Program Memory (Flash), Core Architecture, Operating Temperature.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PIC18F66K22-I/PT
✅ Drop-In✓ In Stock
$3.96 / Unit
View Datasheet →PIC18F65K22T-I/PT
✅ Drop-In✓ In Stock
$2.88 / Unit
View Datasheet →PIC18F66K22T-I/MR
✅ Drop-In✓ In Stock
$4.2 / Unit
View Datasheet →PIC18F65K22-I/PT
✅ Drop-In✓ In Stock
$3.45 / Unit
View Datasheet →PIC18F66K22T-I/MRRSL
✅ Drop-In✓ In Stock
$2.85 / Unit
View Datasheet →PIC18F66K22T-I/PT Maximum Ratings & Electrical Characteristics
| Product Family | PIC18F XLP 18K |
| Core | PIC 8-bit |
| Program Memory (Flash) | 64 KB (32K x 16) |
| Data RAM | 4 KB |
| EEPROM | 1 KB |
| Maximum CPU Frequency | 64 MHz |
| MIPS | 16 MIPS |
| Operating Voltage Range | 1.8 V to 5.5 V |
| I/O Pins | 54 |
| A/D Converter | 12-bit, up to 16 channels |
| Analog Comparators | 2 |
| Timers | 7 (8/16-bit) |
| CTMU | Yes (Charge Time Measurement Unit) |
| Communication Interfaces | EUSART, SPI, I2C |
| Package | 64-pin TQFP (PT) 10x10 mm |
| Operating Temperature | -40C to +85C (Industrial) |
| Mounting Type | Surface Mount |
| RoHS Status | Compliant |
PIC18F66K22T-I/PT Pin Configuration
| Pin 1 | RC0 — Digital I/O / T0CKI / CCP8 |
| Pin 2 | RC1 — Digital I/O / CCP2 |
| Pin 3 | RC2 — Digital I/O / CCP1 |
| Pin 4 | RC3 — Digital I/O / SCL1 |
| Pin 5 | RC4 — Digital I/O / SDA1 |
| Pin 6 | RC5 — Digital I/O / SDO1 |
| Pin 7 | RC6 — Digital I/O / TX1 |
| Pin 8 | RC7 — Digital I/O / RX1 |
| Pin 9 | RD0 — Digital I/O / AD0+ / CTMU channel |
| Pin 10 | RD1 — Digital I/O / AD1+ / CTMU channel |
| Pin 11 | RD2 — Digital I/O / AD2+ / CTMU channel |
| Pin 12 | RD3 — Digital I/O / AD3+ / CTMU channel |
| Pin 13 | RC4_REMAP — See datasheet for 64-pin alternate function map |
| Pin 14 | VDD — Digital supply (1.8 V - 5.5 V) |
| Pin 15 | VSS — Digital ground |
| Pin 16 | RB0 — Digital I/O / INT0 / AN12 |
| Pin 17 | RB1 — Digital I/O / INT1 / AN10 / CTED1 |
| Pin 18 | RB2 — Digital I/O / INT2 / AN8 / CTED2 |
| Pin 19 | RB3 — Digital I/O / INT3 / AN9 / CTED3 |
| Pin 20 | RB4 — Digital I/O / AN11 |
| Pin 21 | RB5 — Digital I/O / AN13 |
| Pin 22 | RB6 — Digital I/O / ICSPCLK |
| Pin 23 | RB7 — Digital I/O / ICSPDAT |
| Pin 24 | VDDCORE — Core logic regulator output (decouple per datasheet) |
| Pin 25 | RE0 — Digital I/O / AN5 |
| Pin 26 | RE1 — Digital I/O / AN6 |
| Pin 27 | RE2 — Digital I/O / AN7 |
| Pin 28 | RE3 — Digital I/O / AN15 / CTMU |
| Pin 29 | RA0 — Digital I/O / AN0 / C1IN+ |
| Pin 30 | RA1 — Digital I/O / AN1 / C2IN+ |
| Pin 31 | RA2 — Digital I/O / AN2 / VREF- |
| Pin 32 | RA3 — Digital I/O / AN3 / VREF+ |
| Pin 33 | RA4 — Digital I/O / AN4 / C1OUT |
| Pin 34 | RA5 — Digital I/O / AN14 / C2OUT / HLVDIN |
| Pin 35 | RA6 — Digital I/O / OSC2 |
| Pin 36 | RA7 — Digital I/O / OSC1 |
| Pin 37 | VSS — Digital ground |
| Pin 38 | VDD — Digital supply |
| Pin 39 | RF0 — Digital I/O / AN16 |
| Pin 40 | RF1 — Digital I/O / AN6 alt |
| Pin 41 | RF2 — Digital I/O |
| Pin 42 | RF3 — Digital I/O |
| Pin 43 | RF4 — Digital I/O |
| Pin 44 | RF5 — Digital I/O |
| Pin 45 | RF6 — Digital I/O |
| Pin 46 | RF7 — Digital I/O |
| Pin 47 | RG0 — Digital I/O |
| Pin 48 | RG1 — Digital I/O |
| Pin 49 | RG2 — Digital I/O |
| Pin 50 | RG3 — Digital I/O |
| Pin 51 | RG4 — Digital I/O |
| Pin 52 | AVDD — Analog supply |
| Pin 53 | AVSS — Analog ground |
| Pin 54 | RH0 — Digital I/O / AN23 |
| Pin 55 | RH1 — Digital I/O / AN22 |
| Pin 56 | RH2 — Digital I/O / AN21 |
| Pin 57 | RH3 — Digital I/O / AN20 |
| Pin 58 | RH4 — Digital I/O |
| Pin 59 | RH5 — Digital I/O |
| Pin 60 | RH6 — Digital I/O |
| Pin 61 | RH7 — Digital I/O |
| Pin 62 | RJ0 — Digital I/O |
| Pin 63 | RJ1 — Digital I/O |
| Pin 64 | MCLR — Master Clear / Reset (active-low) |
Typical Applications
PIC18F66K22T-I/PT is suitable for 6 applications: Industrial Control Panel, Capacitive Touch User Interface, Battery-Powered IoT Sensor Node, Building Automation / HVAC Controller, Medical Instrument Data Acquisition, USB / HID Peripheral Interface.
Industrial Control Panel
The PIC18F66K22T-I/PT is well suited for industrial control panels where its 54 GPIO pins drive keypads, status LEDs, segment displays, and relay outputs. The 64 KB Flash stores communication stacks (Modbus, CAN derivatives) and HMI logic, while nanoWatt XLP idle modes cut standby current below 100 nA - critical for always-on factory floor installations. The 12-bit ADC with up to 16 channels samples analog sensor inputs (temperature, pressure, 4-20 mA loops), and CTMU supports sealed membrane keypads without external touch ICs. Compared with discrete logic designs, integrating all peripherals in one TQFP-64 package reduces PCB area, BOM cost, and qualification effort for industrial -40C to +85C operation.
Recommended
Capacitive Touch User Interface
The integrated CTMU plus 12-bit ADC makes the PIC18F66K22T-I/PT ideal for capacitive touch UIs in appliances, automotive HVAC panels, and consumer electronics. CTMU sources a precision constant current into touch pads; the ADC measures the resulting charge time, translating capacitance changes into button presses, sliders, or proximity wake events. Combined with nanoWatt XLP deep sleep, the MCU can wake on touch, run the UI, then return to sub-microamp standby - extending battery life in portable products. The 64 KB Flash accommodates Microchip's mTouch libraries, while 54 I/O pins support large touch matrices and the LED/buzzer feedback typically required behind the panel.
Recommended
Battery-Powered IoT Sensor Node
The PIC18F66K22T-I/PT's nanoWatt XLP technology delivers sleep currents in the tens of nanoamps and active currents around 1-2 mA at 1 MHz, making it a strong fit for battery-powered IoT sensor nodes on coin cells or 2x AA packs. Its 1.8 V minimum Vdd allows direct connection to single-cell Li-ion or 3 V coin cells. The CTMU drives resistive/capacitive sensor excitation; the 12-bit ADC digitizes readings; EUSART/SPI/I2C connect to radios or nonvolatile memories. With 4 KB SRAM, designers can buffer sensor frames before transmission, while 64 KB Flash supports application logic, wireless protocol stacks, and OTA bootloader stubs.
Recommended
Building Automation / HVAC Controller
Building automation and HVAC controllers demand a balance of analog sensing, digital control, and low standby power - exactly what the PIC18F66K22T-I/PT delivers. The 12-bit ADC scans thermistors and 0-10 V actuator feedback; PWM channels drive fan motors and damper actuators; EUSART interfaces to wall modules or Modbus networks. nanoWatt XLP keeps total standby draw below IECC energy-budget limits, while 64 KB Flash holds control loops, scheduling tables, and BACnet/MQTT-style protocol glue. Industrial temperature grade (-40C to +85C) supports rooftop and plant-room deployment.
Recommended
Medical Instrument Data Acquisition
The PIC18F66K22T-I/PT is widely deployed in low-to-mid complexity medical instruments - glucometers, spirometers, point-of-care analyzers - where its 12-bit ADC, CTMU, and rich I/O set provide accurate sensor readout without external signal-chain ICs. The 4 KB SRAM buffers sample streams, while the 64 KB Flash holds calibration tables, lookup-based linearizations, and simple UI flows. nanoWatt XLP supports battery-powered handheld use with multi-month coin-cell life; 54 I/Os are sufficient for segmented displays, keypads, and LEDs. Designers should note this part is not itself medical-grade certified - the OEM bears IEC 60601 system-level responsibility.
Recommended
USB / HID Peripheral Interface
Though the PIC18F66K22T-I/PT lacks native USB, its EUSART/SPI/I2C set and 16 MIPS throughput make it an excellent companion MCU to external USB bridges or as a USB-capable sibling (e.g., PIC18F45K50, PIC18F14K50). It can act as a HID-class device controller for custom peripherals (game controllers, programmable keypads, instrumentation front-ends), using 54 GPIOs to scan switch matrices and drive RGB indicators. CTMU supports touch overlays for HID devices, and 4 KB SRAM buffers HID reports. With 64 KB Flash, full HID descriptors and firmware updates fit comfortably, and nanoWalt XLP helps battery-powered HID peripherals meet standby budgets.
Recommended
Recommended Products Summary
Engineering reference data for PIC18F66K22T-I/PT — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC18F66K22-I/PT | PIC18F65K22T-I/PT | PIC18F66K22T-I/MR | PIC18F65K22-I/PT | PIC18F66K22T-I/MRRSL |
|---|---|---|---|---|---|---|
| Package | 64-TQFP (PT) 10x10 mm | 64-TQFP (PT) - same | 64-TQFP (PT) - same | 64-TQFP (PT) - same | 64-TQFP (PT) - same | 64-TQFP (PT) - same |
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Program Memory (Flash) | 64 KB | 64 KB | 64 KB | 64 KB | 64 KB | 64 KB |
| Data RAM | 4 KB | 4 KB | 4 KB | 4 KB | 4 KB | 4 KB |
| EEPROM | 1 KB | 1 KB | 1 KB | 1 KB | 1 KB | 1 KB |
| Max CPU Frequency | 64 MHz | 64 MHz | 64 MHz | 64 MHz | 64 MHz | 64 MHz |
| I/O Pins | 54 | 54 | 54 | 54 | 54 | 54 |
| A/D Converter | 12-bit | 12-bit | 12-bit | 12-bit | 12-bit | 12-bit |
| CTMU | Yes | Yes | Yes | Yes | Yes | Yes |
| Operating Voltage | 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 | 1.8 V to 5.5 V |
| Operating Temperature | -40C to +85C | -40C to +85C | -40C to +85C | -40C to +85C | -40C to +85C | -40C to +85C |
| Packing Format | Tape & Reel | Tray | Tape & Reel | Tape & Reel | Tray | Tape & Reel (RSL) |
Key Differentiators
- Integrated CTMU for capacitive touch (vs PIC18F45K22-I/PT)
- nanoWatt XLP deep-sleep current < 100 nA (vs PIC18F4620-I/PT (legacy PIC18F4620))
- 54 GPIO in TQFP-64 with extensive analog integration (vs PIC18F46K22T-I/PT (40-pin TQFP))
Design Notes
Estimated: at 64 MHz, Vdd = 5 V, and all peripherals active, active current is on the order of 8-12 mA - meaningful for coin-cell designs. Use nanoWatt XLP sleep modes (Sleep, Idle, RTCC) to drop current below 100 nA when idle, then wake on INT, IOC, or RTCC alarm. Decouple Vdd/Vss pairs with 100 nF ceramic at each supply cluster and a bulk 10 uF tantalum or ceramic at the regulator output, per Microchip TB0763 layout guidance for XLP designs.
Route AVdd/AVss as dedicated analog supply/ground pairs, placing 100 nF + 10 uF decoupling capacitors within 5 mm of the AVdd pin to preserve ADC SNR. Keep ADC traces short and away from switching nodes (PWM, EUSART clocks). MCLR should have a 10 kohm pull-up and a 100 nF cap to ground for in-circuit serial programming (ICSP) reliability. Use a continuous ground pour on the top layer under the TQFP-64 footprint for thermal spreading.
Do not exceed 5.5 V on any pin - the PIC18F66K22 is a 5 V-tolerant part, not 5.5 V-tolerant. Below 3.0 V the maximum CPU frequency derates; consult the datasheet Fosc/Vdd graph before selecting oscillator settings. CTMU calibration depends on ADC and bandgap stability - perform calibration at the actual operating temperature for best capacitive-touch results. Configuration bits must be set explicitly; defaults leave the part in an unusable state.
For SPI runs above 10 MHz, add 33 ohm series resistors at the MCU outputs to dampen reflections, and ensure the slave device trace length is < 50 mm or matched within 5 mm of other bus traces. For EUSART at high baud rates with long cables, use TVS protection and a series resistor at the driver. For I2C, ensure pull-ups are sized correctly: 4.7 kohm at 5 V for 100 kHz, 2.2 kohm for 400 kHz.
Compliance Information
RoHS compliant per Microchip product page. Not AEC-Q100 qualified - for automotive, evaluate PIC18FxxKxx AEC-Q100 variants in the Microchip automotive MCU portfolio.
