PIC18F66K90T-I/MR - 64KB Flash, 8-bit MCU w/ LCD | Microchip
MPN: PIC18F66K90T-I/MR ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $3.87 | $3.87 |
| 10 | $3.62 | $36.20 |
| 100 | $3.18 | $318.00 |
| 500 | $2.79 | $1,395.00 |
| 1,000 | $2.55 | $2,550.00 |
PIC18F66K90T-I/MR Overview
An 8-bit microcontroller (MCU) is a single-chip computer that integrates a CPU, RAM, program memory, I/O peripherals, and often analog/digital interfaces on one die. PIC18F devices use Microchip's enhanced Harvard RISC architecture with a 16-bit instruction word, placing them in the broader hierarchy: microcontroller -> embedded controller -> semiconductor -> integrated circuit. The K90 sub-family adds segmented LCD glass driving and ultra-low-power sleep modes targeting human-interface and battery-powered products.
Key features include 24 channels of capacitive touch sensing via the CTMU, integrated segmented LCD driver (up to 192 segments), 12-bit A/D converter, multiple PWM/ECCP modules, and nanoWatt XLP technology with currents as low as 20nA in deep sleep. The VQFN-64 (MR) 9x9 mm package with exposed pad supports thermal dissipation for industrial-grade -40C to +85C operation. 54 digital I/O pins enable rich human-machine interface designs.
Architecturally the device uses a modified Harvard core with hardware multiply, 31-level stack, and 32 interrupt sources. The LCD module supports static, 1/2, 1/3, 1/4 duty and 1/2, 1/3 bias with an integrated charge pump enabling LCD operation from a single low-voltage supply, eliminating the need for a boosted analog rail.
Typical applications include battery-powered thermostats, portable medical monitors, industrial control panels with LCD, electronic shelf labels, gas/water meters, and capacitive-touch human-interface panels. The combination of XLP low power, integrated LCD, and CTMU touch makes it well-suited for any segment-LCD display product that needs a touch overlay and long battery life.
When designing with this part, allocate sufficient PCB copper under the exposed pad for thermal relief and connect it with multiple vias to the inner ground plane. The CTMU calibration procedure in the datasheet should be followed exactly for accurate touch sensing. Decoupling must include 100nF ceramic plus bulk capacitance near each supply pin.
This page synthesizes distributor pricing, drop-in alternatives, and practical design notes not found on any single manufacturer page.
Drop-in alternatives for PIC18F66K90T-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 PIC18F66K90T-I/MR (same form factor and footprint) — differing in Package, ADC, LCD Driver, Core Architecture, I/O Pins.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PIC18F66K90-I/MR
✅ Drop-In✓ In Stock
$3.62 / Unit
View Datasheet →PIC18F65K90T-I/MR
✅ Drop-In✓ In Stock
$1.95 / Unit
View Datasheet →PIC18F65K90T-I/MRRSL
✅ Drop-In✓ In Stock
$4.1 / Unit
View Datasheet →PIC18F66K40T-I/MR
✅ Drop-In✓ In Stock
$2.46 / Unit
View Datasheet →PIC18F66K22T-I/MR
✅ Drop-In✓ In Stock
$4.2 / Unit
View Datasheet →PIC18F66K90T-I/MR Maximum Ratings & Electrical Characteristics
| Core Architecture | PIC 8-bit (enhanced Harvard RISC) |
| Series | PIC18F87K90 family, PIC XLP 18K |
| Program Memory (Flash) | 64 KB (32K x 16) |
| Data RAM | 4 KB |
| Data EEPROM | 1 KB |
| Maximum CPU Speed | 64 MHz |
| Supply Voltage (VDD) | 1.8 V to 3.6 V (LCD charge-pump configuration extends usable range; see datasheet) |
| I/O Pins | 54 |
| Package | VQFN-64 (MR) 9x9 mm with exposed thermal pad |
| LCD Driver | Integrated, up to 192 segments |
| Touch Sensing | CTMU, 24 channels |
| Operating Temperature | -40C to +85C (industrial) |
| Low-Power Technology | nanoWatt XLP (sleep currents down to nA range) |
| Mounting Type | Surface Mount |
| RoHS Status | Compliant (per Microchip product page) |
PIC18F66K90T-I/MR vqfn-64 (mr) 9x9 mm with exposed thermal pad Pin Configuration Guide
Pin configuration for PIC18F66K90T-I/MR (vqfn-64 (mr) 9x9 mm with exposed thermal pad package). This digital IC includes GPIO, communication interfaces (UART, SPI, I2C), and power pins. Refer to the manufacturer datasheet for alternate pin functions and configuration options. Essential for embedded system design and PCB layout.
No detailed pinout data available for PIC18F66K90T-I/MR.
Refer to the datasheet for full pin configuration.
Typical Applications
PIC18F66K90T-I/MR is suitable for 6 applications: Battery-Powered Thermostat with LCD, Industrial Control Panel with LCD and Touch, Portable Medical Monitor, Electronic Shelf Label, Smart Gas/Water Meter with LCD Readout, Capacitive-Touch Home Appliance Interface.
Battery-Powered Thermostat with LCD
The PIC18F66K90T-I/MR's integrated 192-segment LCD driver eliminates the need for an external LCD controller, and the nanoWatt XLP technology with 20 nA deep-sleep currents extends battery life over multi-year deployments. The 64 KB Flash supports HVAC control firmware plus graphical segments for temperature setpoints, schedule, and system status. Operating at 1.8-3.6 V from two AA cells with the on-chip LCD charge pump means the same supply powers both logic and the glass. Engineers typically pair this with a low-cost thermistor on the ADC and an ECCP PWM for triac-fired HVAC control. Pin-compatible drop-ins like PIC18F65K90T-I/MR support cost-down without PCB changes.
Recommended
Industrial Control Panel with LCD and Touch
The PIC18F66K90T-I/MR integrates segmented LCD driving and CTMU capacitive touch in one IC, replacing what would otherwise require separate display and touch controller chips. With 24 CTMU channels, designers can implement button, slider, and wheel touch interfaces directly on the display glass, reducing BOM and PCB area. The 64 MHz CPU executes control loop firmware in real time while servicing display refresh and touch scans. The 54 I/O pins accept industrial pushbuttons, rotary encoders, and sensor inputs. The MR package's exposed pad offers good thermal performance for enclosed industrial cabinets. Pair with the MCP1700 LDO for clean rail regulation.
Recommended
Portable Medical Monitor
For handheld patient monitors the PIC18F66K90T-I/MR delivers 64 KB Flash for vital-sign firmware, integrated LCD for readouts, and nanoWatt XLP currents that allow weeks of standby from a single battery. The CTMU's 24 touch channels support sealed capacitive keypads that survive hospital-grade disinfection, important for infection control. The 8-bit RISC core executes low-power signal processing between samples, with the ADC capturing sensor data from pulse oximetry or temperature front-ends. The VQFN-64 (MR) 9x9 mm footprint fits compact handheld enclosures. Per the PIC18F87K90 family datasheet, the device is rated -40C to +85C, suitable for clinical environments.
Recommended
Electronic Shelf Label
The PIC18F66K90T-I/MR's integrated segmented LCD driver, 20 nA deep-sleep current, and wireless-friendly low-power architecture suit battery-powered electronic shelf labels (ESLs) that must run for 5-10 years on a coin cell. The on-chip LCD charge pump eliminates the external boost converter typically needed for 5V glass at 1.8V VDD. The 64 KB Flash accommodates wireless stack, display rendering, and product database caching. CTMU touch enables user interaction for price verification. The MR package's small 9x9 mm footprint supports the small ESL PCB. Pair with a sub-GHz RF transceiver such as the MRF89XA for ESLs in retail environments.
Recommended
Smart Gas/Water Meter with LCD Readout
The PIC18F66K90T-I/MR drives the segmented LCD on utility meters directly, and the CTMU supports touch buttons for user interaction without mechanical switches that wear out. The 64 MHz core and 64 KB Flash accommodate metrology algorithms, LCD rendering, and optional wireless M-Bus or LoRaWAN communications stacks. nanoWatt XLP currents below 1 uA in sleep support the 10-15 year battery life required by utility metering applications. The -40C to +85C industrial range covers outdoor meter installations. The MR package's exposed pad aids thermal dissipation in sealed meter enclosures. Per the PIC18F87K90 family datasheet, ECCP and timer resources are ample for flow-sensor pulse counting.
Recommended
Capacitive-Touch Home Appliance Interface
Appliance front panels increasingly replace mechanical buttons with capacitive touch, and the PIC18F66K90T-I/MR's 24-channel CTMU and integrated LCD driver enable a single-chip HMI solution. The 64 KB Flash holds appliance firmware plus state-machine control code, and the 4 KB RAM supports display buffer and touch-scan history. The 64 MHz CPU services touch scanning, LCD refresh, and motor-control feedback loops simultaneously. The MR VQFN-64 package's compact 9x9 mm footprint fits behind a sealed overlay, with the exposed pad offering thermal headroom for continuous operation. Pair with the MCP23016 for additional I/O expansion if more buttons or LEDs are required.
Recommended
Recommended Products Summary
Engineering reference data for PIC18F66K90T-I/MR — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC18F66K90-I/MR | PIC18F65K90T-I/MR | PIC18F65K90T-I/MRRSL | PIC18F66K40T-I/MR | PIC18F66K22T-I/MR |
|---|---|---|---|---|---|---|
| Package | VQFN-64 (MR) 9x9 mm | VQFN-64 (MR) 9x9 mm - same | VQFN-64 (MR) 9x9 mm - same | VQFN-64 (MR) 9x9 mm - same | VQFN-64 (MR) 9x9 mm - same | VQFN-64 (MR) 9x9 mm - same |
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Integrated LCD Driver | Yes (up to 192 segments) | Yes (up to 192 segments) | Yes (up to 192 segments) | Yes (up to 192 segments) | No | No |
| CTMU Capacitive Touch Channels | 24 | 24 | 24 | 24 | No | No |
Key Differentiators
- Integrated 192-segment LCD driver with on-chip charge pump (vs PIC18F66K22T-I/MR)
- 24-channel CTMU capacitive touch sensing on-chip (vs PIC18F66K22T-I/MR)
- nanoWatt XLP technology with ~20 nA deep-sleep current (vs PIC18F66K40T-I/MR)
Design Notes
Estimated: at 64 MHz core and typical 25 mA active current, the VQFN-64 (MR) package dissipates ~80 mW worst case. The exposed thermal pad must be soldered to a copper pour of at least 100 mm^2 on the top layer, stitched with 4-8 thermal vias (0.3 mm drill, 0.6 mm pad) to the inner ground plane. Without this stitching the junction-to-ambient thermal resistance can exceed 50 C/W, risking thermal shutdown in enclosed industrial cabinets.
Place a 100 nF ceramic decoupling capacitor within 5 mm of each VDD/VDDCORE/VSS pair, plus a single 4.7 uF bulk capacitor near the IC. The LCD charge-pump pins (VLCD) require their own 1 uF to 4.7 uF reservoir capacitor per the PIC18F87K90 family datasheet. Use X7R or X5R ceramic dielectrics - Y5V parts derate capacitance badly at low VDD and disrupt LCD contrast.
Per the PIC18F87K90 family datasheet, the CTMU must be calibrated for each design using the internal current source reference and the on-chip ADC - skipping this step yields touch-sensing errors of 50% or more. Also ensure unused I/O pins are configured as outputs driven low (not inputs floating) to minimize deep-sleep leakage that would otherwise defeat the nanoWatt XLP power budget.
Keep LCD segment and common traces short and well-matched in length within each COM/SEG pair to avoid ghosting. Route CTMU touch traces as guarded capacitive-sense lines with a ground-fill shield, keeping them away from switching signals like PWM outputs. The PIC18F87K90 family datasheet shows reference layouts in the 'LCD and CTMU Design Considerations' application note section; following these reference layouts avoids first-pass contrast and touch-sensitivity rework.
Compliance Information
RoHS compliant per Microchip product page. AEC-Q100 status not explicitly listed for the -I industrial temperature grade; check Microchip's automotive-grade PIC18F family variants for AEC-Q100 qualified equivalents. Halogen-free status not confirmed in retrieved data.
