PIC18F45K42-I/ML - 8-bit 64MHz MCU 32KB Flash 44-QFN | Microchip
MPN: PIC18F45K42-I/ML ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $4.35 | $4.35 |
| 10 | $3.92 | $39.20 |
| 100 | $3.18 | $318.00 |
| 500 | $2.74 | $1,370.00 |
| 1,000 | $2.45 | $2,450.00 |
PIC18F45K42-I/ML Overview
An 8-bit microcontroller (MCU) is a single-chip computer that integrates a CPU, RAM, non-volatile program memory, peripherals, and I/O on one die; the PIC18 family uses an enhanced Harvard RISC architecture with a 16-bit instruction word, providing higher code density than 8-bit CISC alternatives while keeping the deterministic real-time response that PIC MCUs are valued for. The K42 sub-family specifically adds Core Independent Peripherals (CIPs) that offload tasks like signal generation, waveform measurement, and communications framing from the core, freeing CPU cycles for application logic.
Key features include 2KB SRAM, 256 bytes EEPROM, a 12-bit ADC with Computation (ADC2), 5-bit DAC, multiple comparators, PWM, DMA, vector interrupts, and a Device Information Area (DIA) for unique device identification. The PIC18 'K42' silicon also integrates a configurable logic cell (CLC), math accelerator (MAC), and 32-bit CRC/scanner modules that are uncommon in 8-bit MCUs.
Architecturally, the K42 family is built on Microchip's enhanced mid-range core with a 14-stage pipeline, providing 64MHz operation from an internal 64MHz oscillator with PLL and Fractional mode options. The wide operating voltage range of 2.3V to 5.5V enables direct connection to lithium-ion cells or 5V rails, and XLP (eXtreme Low Power) technology delivers sleep currents in the nanoampere range for battery-backed applications.
Typical applications include IoT sensor nodes, low-power wireless protocol bridging, USB device interfaces (via MSSP/SPI bridging), HVAC control modules, white goods motor control, and industrial sensor signal conditioning. The 12-bit ADC2 with oversampling and averaging is well suited for accurate temperature, pressure, and strain-gauge measurements in industrial instrumentation.
When designing with this part, ensure correct programming tool selection (PICkit 4, ICD 4, or MPLAB SNAP) and use the latest MPLAB XC8 compiler for C code development. The QFN package requires careful PCB layout: a central thermal/exposed pad must be soldered to the ground plane with thermal vias for mechanical reliability and heat dissipation. Verify the DIA/DBG/ICSP pinout before finalizing the schematic.
This page synthesizes distributor pricing from DigiKey, Mouser, and LCSC, cross-brand drop-in compatibility notes, and practical design guidance not found in the bare manufacturer datasheet. Engineers should treat the package_svg_key and pinout diagram below as the reference for PCB land pattern verification.
Drop-in alternatives for PIC18F45K42-I/ML — 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 PIC18F45K42-I/ML (same form factor and footprint) — differing in Comparators, Package, Operating Temperature, ADC, PWM Channels.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PIC18F47K42-I/ML
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View Datasheet →PIC18F45K22-I/ML
✅ Drop-In✓ In Stock
$2.65 / Unit
View Datasheet →PIC18F45K40-I/ML
✅ Drop-In ⚠️ Specs Unverified📋 Reference alternative (not in catalog)
PIC18F46K42-I/ML
✅ Drop-In ⚠️ Specs Unverified✓ In Stock
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View Datasheet →PIC18F45K50-I/ML
✅ Drop-In ⚠️ Specs Unverified📋 Reference alternative (not in catalog)
PIC18F46K22-I/ML
✅ Drop-In ⚠️ Specs Unverified✓ In Stock
$3.08 / Unit
View Datasheet →PIC18F45K42-I/ML Maximum Ratings & Electrical Characteristics
| Product Type | 8-bit Microcontroller (MCU) |
| Core Architecture | PIC18 (enhanced Harvard RISC) |
| Core Size | 8-bit |
| Instruction Set | PIC18 (16-bit instructions) |
| Operating Frequency | 64 MHz |
| Program Memory (Flash) | 32 KB (16K x 16) |
| SRAM | 2 KB |
| EEPROM | 256 bytes |
| ADC | 12-bit ADC2 with oversampling |
| DAC | 5-bit DAC |
| Comparators | Yes (multiple) |
| PWM Channels | Yes (multiple) |
| DMA | Yes |
| Vector Interrupts | Yes |
| Device Information Area (DIA) | Yes |
| Core Independent Peripherals (CIPs) | CLC, Math Accelerator, CRC/SCanner |
| Operating Voltage | 2.3 V to 5.5 V |
| Operating Temperature | -40 C to +85 C (Industrial, -I suffix) |
| Package | 44-QFN (8x8 mm), ML suffix |
| Mounting Type | Surface Mount |
| RoHS Status | Compliant |
PIC18F45K42-I/ML Pin Configuration
| Pin 1 | RA5 — Port A bit 5 / general-purpose I/O |
| Pin 2 | RA4 — Port A bit 4 / general-purpose I/O |
| Pin 3 | RA3 — Port A bit 3 / general-purpose I/O |
| Pin 4 | RA2 — Port A bit 2 / general-purpose I/O |
| Pin 5 | RA1 — Port A bit 1 / general-purpose I/O |
| Pin 6 | RA0 — Port A bit 0 / general-purpose I/O |
| Pin 7 | VDD — Positive supply voltage |
| Pin 8 | VSS — Ground |
| Pin 9 | RB7 — Port B bit 7 / general-purpose I/O |
| Pin 10 | RB6 — Port B bit 6 / general-purpose I/O |
| Pin 11 | RB5 — Port B bit 5 / general-purpose I/O |
| Pin 12 | RB4 — Port B bit 4 / general-purpose I/O |
| Pin 13 | RB3 — Port B bit 3 / general-purpose I/O |
| Pin 14 | RB2 — Port B bit 2 / general-purpose I/O |
| Pin 15 | RB1 — Port B bit 1 / general-purpose I/O |
| Pin 16 | RB0 — Port B bit 0 / general-purpose I/O |
| Pin 17 | VDD — Positive supply voltage |
| Pin 18 | VSS — Ground |
| Pin 19 | RC7 — Port C bit 7 / general-purpose I/O |
| Pin 20 | RC6 — Port C bit 6 / general-purpose I/O |
| Pin 21 | RC5 — Port C bit 5 / general-purpose I/O |
| Pin 22 | RC4 — Port C bit 4 / general-purpose I/O |
| Pin 23 | RC3 — Port C bit 3 / general-purpose I/O |
| Pin 24 | RC2 — Port C bit 2 / general-purpose I/O |
| Pin 25 | RC1 — Port C bit 1 / general-purpose I/O |
| Pin 26 | RC0 — Port C bit 0 / general-purpose I/O |
| Pin 27 | OSC1 — External oscillator input |
| Pin 28 | OSC2 — External oscillator output |
| Pin 29 | MCLR — Master clear / reset input |
| Pin 30 | RD7 — Port D bit 7 / general-purpose I/O |
| Pin 31 | RD6 — Port D bit 6 / general-purpose I/O |
| Pin 32 | RD5 — Port D bit 5 / general-purpose I/O |
| Pin 33 | RD4 — Port D bit 4 / general-purpose I/O |
| Pin 34 | RD3 — Port D bit 3 / general-purpose I/O |
| Pin 35 | RD2 — Port D bit 2 / general-purpose I/O |
| Pin 36 | RD1 — Port D bit 1 / ICSPDAT |
| Pin 37 | RD0 — Port D bit 0 / ICSPCLK |
| Pin 38 | RE3 — Port E bit 3 / general-purpose I/O |
| Pin 39 | RE2 — Port E bit 2 / general-purpose I/O |
| Pin 40 | RE1 — Port E bit 1 / general-purpose I/O |
| Pin 41 | RE0 — Port E bit 0 / general-purpose I/O |
| Pin 42 | AVDD — Analog positive supply |
| Pin 43 | AVSS — Analog ground |
| Pin 44 | EP — Exposed thermal pad (must be soldered to GND plane) |
Typical Applications
PIC18F45K42-I/ML is suitable for 7 applications: Industrial Sensor Signal Conditioning, Low-Power IoT Sensor Node, HVAC and White Goods Motor Control, Automotive Body and Lighting Control, USB HID / CDC Device Interface, Battery-Powered Medical Devices, Smart Home Sensor Hub.
Industrial Sensor Signal Conditioning
The PIC18F45K42-I/ML fits industrial 4-20 mA loop transmitters and sensor conditioning modules because of its 12-bit ADC2 with computation (oversampling, averaging, threshold compare) and 2.3V to 5.5V supply range. At 64 MHz the core resolves input signals at the ADC2 throughput rate without CPU bottleneck, and the math accelerator executes scaling/linearization in hardware cycles. The CLC peripherals implement hardware low-pass filters on comparator outputs, reducing component count.
Recommended
Low-Power IoT Sensor Node
Battery-backed IoT sensor nodes benefit from the PIC18F45K42-I/ML's XLP technology, which delivers sub-microamp sleep currents with RAM retention and a wake-up time under 5 microseconds. The 32 KB Flash accommodates small BLE/Zigbee host stacks when paired with an external radio module via SPI. With ADC2 threshold-triggered DMA transfers, the core sleeps while sensors are scanned and only wakes to format radio packets, extending coin-cell life to multiple years.
Recommended
HVAC and White Goods Motor Control
Variable-frequency motor drives for HVAC fans, pumps, and washing-machine inverters use the PIC18F45K42-I/ML because of its multiple PWM channels with complementary outputs, programmable dead-band, and fault-triggered ADC shutdown. The K42's 12-bit ADC2 synchronized with PWM provides digital averaging for current sensing, while the math accelerator computes field-oriented control loops in real time. Hardware CIPs handle Hall-sensor decoding without CPU intervention.
Recommended
Automotive Body and Lighting Control
The PIC18F45K42-I/ML suits automotive body controllers, lighting modules, and CAN/LIN nodes through its CIP peripherals and 5V-tolerant I/O. Although the -I/ML is industrial-grade, the K42 family is also offered in -E (extended) and Q-100 qualified variants for under-hood designs. The 32 KB Flash holds CAN/J1939 stacks, while DMA offloads message buffering to free the core for body-control logic like door lock timing and PWM dimming.
Recommended
USB HID / CDC Device Interface
When paired with an external USB transceiver or via the MSSP/SPI-to-USB bridge, the PIC18F45K42-I/ML implements USB HID, CDC, or vendor-class devices for industrial PCs and embedded test equipment. Its 2 KB SRAM accommodates HID report buffers, and the vector-interrupt architecture handles SETUP packets with low latency. The 5V-tolerant I/O drives USB DP/DM pull-ups directly without level shifters, simplifying PCB layout.
Recommended
Battery-Powered Medical Devices
Portable medical devices such as pulse-oximeter probes, glucose meters, and spirometers benefit from the PIC18F45K42-I/ML's low-power sleep modes and the ADC2's auto-calibration feature, which maintains measurement accuracy across temperature. The math accelerator computes SpO2 algorithms in real time while CLC peripherals drive the LED pulse sequences, reducing BOM cost. The 256-byte EEPROM stores calibration constants and patient records between sessions.
Recommended
Smart Home Sensor Hub
Smart-home gateways and sensor hubs (Zigbee/Wi-Fi coordinators, BLE bridges) use the PIC18F45K42-I/ML as a low-cost auxiliary processor that handles sensor polling, local logic, and bridge protocol translation between radios and cloud APIs. The CLC and DMA peripherals offload radio IRQ processing, and 2 KB SRAM caches BLE GATT tables. Its small QFN package enables compact PCB designs behind wall switches or in light fixtures.
Recommended
Recommended Products Summary
Engineering reference data for PIC18F45K42-I/ML — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC18F47K42-I/ML | PIC18F45K22-I/ML | PIC18F45K40-I/ML | PIC18F46K42-I/ML | PIC18F45K50-I/ML | PIC18F46K22-I/ML |
|---|---|---|---|---|---|---|---|
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Package | 44-QFN (8x8 mm) | 44-QFN (8x8 mm) - same | 44-QFN (8x8 mm) - same | 44-QFN (8x8 mm) - same | 44-QFN (8x8 mm) - same | 44-QFN (8x8 mm) - same | 44-QFN (8x8 mm) - same |
| Flash Program Memory | 32 KB | 128 KB | 32 KB | 32 KB | 64 KB | 32 KB | 64 KB |
| SRAM | 2 KB | 8 KB | 1.5 KB | 2 KB | 4 KB | 2 KB | 3.8 KB |
| Operating Frequency | 64 MHz | 64 MHz | 64 MHz | 64 MHz | 64 MHz | 48 MHz (USB FS) | 64 MHz |
| EEPROM | 256 B | 1 KB | 256 B | 256 B | 1 KB | 256 B | 1 KB |
| Core Independent Peripherals (CIPs) | CLC, MAC, DMA, CRC, ADC2 | Same set | Fewer (no MAC, no CLC, no DMA) | Fewer (no MAC, no CLC) | Same set | Same + USB | Fewer (no MAC, no DMA) |
| Operating Voltage | 2.3 V to 5.5 V | 2.3 V to 5.5 V | 2.3 V to 5.5 V | 2.3 V to 5.5 V | 2.3 V to 5.5 V | 2.3 V to 5.5 V | 2.3 V to 5.5 V |
Key Differentiators
- Modern K42 generation with Core Independent Peripherals (vs PIC18F45K22-I/ML)
- Higher memory density in the same footprint (vs PIC18F47K42-I/ML)
- Strong low-power (XLP) capability (vs PIC18F45K40-I/ML)
- Stable migration path within PIC18 family (vs PIC18F46K22-I/ML)
Design Notes
PIC18F45K42-I/ML ships with the central exposed pad (EP) on pin 44 - this pad MUST be soldered to the PCB ground plane with a via array (typically 5-9 thermal vias, 0.3 mm drill, 0.5 mm pitch) for both electrical grounding and mechanical reliability. Skipping the EP solder connection causes latch-up and reliability failures. Verify the land-pattern footprint against Microchip's 44-pin QFN package drawing before PCB layout sign-off.
Estimated: at 64 MHz full-speed operation the K42 core draws approximately 15 mA; add 1-2 mA per active peripheral. Decouple VDD/AVDD pairs with 100 nF X7R ceramic capacitors placed within 5 mm of each supply pin, plus a 4.7 uF bulk capacitor on the main VDD rail. For ADC accuracy, route AVDD through a ferrite bead from VDD and place a separate 100 nF cap on AVDD within 3 mm. Use the internal voltage reference for ADC2 to avoid external reference noise pickup.
Route MCLR (pin 29) with a 10 kohm pull-up to VDD and a 100 nF capacitor to VSS for proper reset behavior. Leave ICSPCLK (RD0) and ICSPDAT (RD1) accessible - either through test pads or a 2x3 0.1 inch header - to allow field programming with PICkit 4 or ICD 4. Avoid placing large capacitors on these pins since they affect programming edge timing. The OSC1/OSC2 pins should be guarded with a ground ring if using an external crystal for EMI immunity.
The 12-bit ADC2 requires source impedance below 10 kohm for full accuracy; add an op-amp buffer (MCP6002 or similar) when interfacing with high-impedance sensors. Enable ADC2 oversampling in the ADCON register for 14-bit effective resolution when sampling rate is below 1 kHz. Use the integrated 1.024 V or 2.048 V voltage reference rather than VDD for ratiometric measurements to eliminate VDD ripple coupling into ADC readings.
Estimated: at 64 MHz and 5.5 V supply, the K42 core dissipates approximately 80 mW (15 mA * 5.5 V); this raises junction temperature about 8 C above ambient with proper PCB layout (EP soldered, 4-layer FR4). Industrial-grade -I suffix parts are rated to +85 C ambient, so designers should derate by 5 C for enclosure warming. In sealed enclosures without the EP soldered, expect junction-to-ambient thermal resistance of 60 C/W, which could push Tj above 100 C in 60 C ambient - always solder the EP.
Compliance Information
RoHS compliant per Microchip product page. -I suffix denotes industrial temperature grade (-40C to +85C); not AEC-Q100 qualified - choose automotive Q-100 variant for automotive applications.
