PIC18F45K22-E/ML - 32KB Flash 8-Bit MCU 48MHz QFN-44 | Microchip
MPN: PIC18F45K22-E/ML ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $3.45 | $3.45 |
| 10 | $3.1 | $31.00 |
| 100 | $2.75 | $275.00 |
| 500 | $2.41 | $1,205.00 |
| 1,000 | $2.1 | $2,100.00 |
| 3,000 | $1.78 | $5,340.00 |
PIC18F45K22-E/ML Overview
A microcontroller (MCU) is a single-chip computer containing a CPU core, non-volatile program memory (Flash), volatile data memory (SRAM), and configurable peripherals. The PIC18F family sits in the broader 8-bit MCU hierarchy as an enhanced mid-range architecture with a 16-bit instruction word, C-optimized compiler support, and advanced peripherals; it belongs to the larger class of microcontrollers within the power management & embedded control semiconductor category. XLP nanoWatt technology specifically targets ultra-low sleep current, making this family well suited to battery-powered products.
Key differentiating features include a 12-bit A/D converter with up to 30 input channels, two analog comparators with selectable references, three ECCP/SCCP PWM/capture modules, two MSSP peripherals for SPI/I2C, two enhanced USART modules, and an on-chip mTouch capacitive sensing module. The integrated CTMU provides accurate time measurement for capacitive touch and general purpose analog functions, and the EUSART auto-baud detection simplifies LIN-connected designs.
The PIC18F45K22 uses an enhanced Harvard RISC architecture with hardware multiply, 31-level hardware stack, and 1,000,000 erase/write cycle Flash endurance. Internal oscillator options (8 selectable frequencies from 31 kHz to 16 MHz) plus PLL allow flexible clocking without external crystals, reducing BOM cost and board area. The device also features an on-chip voltage regulator allowing direct 5 V operation from a single supply.
Typical applications include consumer white goods and HVAC controls, low-power battery-operated sensor nodes, IoT edge nodes, automotive body and interior electronics (with PIC18F45K22-I/ML or automotive-grade derivatives for full AEC-Q100 deployments), industrial automation human-machine interfaces (HMIs), capacitive touch user interfaces, and USB-to-UART bridges via the EUSART. The wide supply range makes it drop-in friendly on both 3.3 V and 5 V rails.
Designers should note that the QFN-44 (8x8 mm) exposed pad must be soldered to the PCB ground plane to meet thermal and electrical performance; do not leave the EP floating. For new designs Microchip recommends the newer PIC18F45Q10 family, which offers updated peripherals and improved current consumption, but the PIC18F45K22-E/ML remains fully active and broadly stocked for legacy designs.
This page synthesizes current distributor pricing and stock, drop-in alternatives in the same QFN-44 package, and practical design notes drawn from the manufacturer datasheet - engineering context not found in the datasheet alone.
Drop-in alternatives for PIC18F45K22-E/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 PIC18F45K22-E/ML (same form factor and footprint) — differing in Package, MSL Level, Program Memory (Flash), Timers, ADC.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PIC18F45K22-I/ML
✅ Drop-In✓ In Stock
$2.65 / Unit
View Datasheet →PIC18F46K22-I/ML
✅ Drop-In✓ In Stock
$3.08 / Unit
View Datasheet →PIC18F44K22-I/ML
✅ Drop-In✓ In Stock
$2.1 / Unit
View Datasheet →PIC18F43K22-I/ML
✅ Drop-In✓ In Stock
$1.95 / Unit
View Datasheet →PIC18F45K22-E/P
✅ Drop-In✓ In Stock
$2.78 / Unit
View Datasheet →PIC18F45K22-E/ML Maximum Ratings & Electrical Characteristics
| Core Architecture | PIC18 8-bit Enhanced Harvard RISC |
| Program Memory (Flash) | 32 KB (16K x 16 instructions) |
| Data SRAM | 1.5 KB (1536 bytes) |
| Data EEPROM | 256 bytes |
| Maximum CPU Speed | 48 MHz (12 MIPS) |
| Supply Voltage Range | 2.3 V to 5.5 V (4.2 V to 5.5 V for -E variant) |
| I/O Pins | 36 |
| ADC | 12-bit, up to 30 channels |
| PWM Modules | 3 (ECCP + 2x ECCP/SCCP) |
| Analog Comparators | 2 |
| UART / EUSART | 2 (with auto-baud) |
| SPI / I2C (MSSP) | 2 |
| Timers | 5 (16-bit and 8-bit) |
| Operating Temperature Range | -40C to +125C (Extended, -E suffix) |
| Package | QFN-44 (8x8 mm) with exposed thermal pad |
| Mounting Type | Surface Mount |
| MSL Level | 3 (168 hours) |
| RoHS Status | Compliant |
| Lead-Free | Yes |
| Low-Power Technology | nanoWatt XLP |
PIC18F45K22-E/ML Pin Configuration
| Pin 1 | RA2/AN2/C2IN+/CTED1/VREF- — GPIO RA2 / ADC ch2 / Comparator2 in+ / CTMU touch / negative voltage reference |
| Pin 2 | RA3/AN3/C1IN+/CTED2/VREF+ — GPIO RA3 / ADC ch3 / Comparator1 in+ / CTMU touch / positive voltage reference |
| Pin 3 | RA4/T0CKI/C1OUT/SRQ — GPIO RA4 / Timer0 clock input / Comparator1 output / SR-latch Q output |
| Pin 4 | RA5/AN4/C2OUT/SRQN/SS1/HLVDIN — GPIO RA5 / ADC ch4 / Comparator2 output / SR-latch Qn / SPI1 SS / HLVD input |
| Pin 5 | RA6/OSC2/CLKO — GPIO RA6 / crystal oscillator output / system clock output |
| Pin 6 | RA7/OSC1/CLKI — GPIO RA7 / crystal oscillator input / system clock input |
| Pin 7 | VSS — Ground reference |
| Pin 8 | VDD — Positive supply voltage (2.3 V to 5.5 V) |
| Pin 9 | RB0/AN12/FLT0/INT0/CTED4 — GPIO RB0 / ADC ch12 / PWM fault input / INT0 / CTMU touch |
| Pin 10 | RB1/AN10/C1INC/CTED5 — GPIO RB1 / ADC ch10 / Comparator1 in- / CTMU touch |
| Pin 11 | RB2/AN8/C2INC/CTED6 — GPIO RB2 / ADC ch8 / Comparator2 in- / CTMU touch |
| Pin 12 | RB3/AN9/CPP1/CTED7 — GPIO RB3 / ADC ch9 / charge pump / CTMU touch |
| Pin 13 | RB4/AN11/KBI0 — GPIO RB4 / ADC ch11 / interrupt-on-change |
| Pin 14 | RB5/KBI1 — GPIO RB5 / interrupt-on-change |
| Pin 15 | RB6/KBI2/PGC — GPIO RB6 / interrupt-on-change / ICD clock (PGC) |
| Pin 16 | RB7/KBI3/PGD — GPIO RB7 / interrupt-on-change / ICD data (PGD) |
| Pin 17 | RC0/SOSCO — GPIO RC0 / secondary oscillator output (32.768 kHz) |
| Pin 18 | RC1/SOSCI — GPIO RC1 / secondary oscillator input |
| Pin 19 | RC2/AN14/CCP1 — GPIO RC2 / ADC ch14 / CCP1 PWM |
| Pin 20 | RC3/AN15/SCL1/SCK1 — GPIO RC3 / ADC ch15 / I2C1 SCL / SPI1 SCK |
| Pin 21 | RC4/AN16/SDA1/SDI1 — GPIO RC4 / ADC ch16 / I2C1 SDA / SPI1 SDI |
| Pin 22 | RC5/AN17/SDO1 — GPIO RC5 / ADC ch17 / SPI1 SDO |
| Pin 23 | RC6/AN18/TX1/CK1 — GPIO RC6 / ADC ch18 / EUSART1 TX / EUSART1 clock |
| Pin 24 | RC7/AN19/RX1/DT1 — GPIO RC7 / ADC ch19 / EUSART1 RX / EUSART1 data |
| Pin 25 | VSS — Ground reference |
| Pin 26 | VDD — Positive supply voltage (2.3 V to 5.5 V) |
| Pin 27 | RD0/AN20/CTED12 — GPIO RD0 / ADC ch20 / CTMU touch |
| Pin 28 | RD1/AN21/CTED13 — GPIO RD1 / ADC ch21 / CTMU touch |
| Pin 29 | RD2/AN22/CTED14 — GPIO RD2 / ADC ch22 / CTMU touch |
| Pin 30 | RD3/AN23/CTED15 — GPIO RD3 / ADC ch23 / CTMU touch |
| Pin 31 | RD4/AN24 — GPIO RD4 / ADC ch24 |
| Pin 32 | RD5/AN25/P1B — GPIO RD5 / ADC ch25 / Enhanced PWM output 1B |
| Pin 33 | RD6/AN26/P1C — GPIO RD6 / ADC ch26 / Enhanced PWM output 1C |
| Pin 34 | RD7/AN27/P1D — GPIO RD7 / ADC ch27 / Enhanced PWM output 1D |
| Pin 35 | RE0/AN5 — GPIO RE0 / ADC ch5 |
| Pin 36 | RE1/AN6 — GPIO RE1 / ADC ch6 |
| Pin 37 | RE2/AN7 — GPIO RE2 / ADC ch7 |
| Pin 38 | RE3/MCLR/VPP — GPIO RE3 / Master Clear (reset, active-low) / programming voltage |
| Pin 39 | RF0/AN16 — GPIO RF0 / ADC ch16 |
| Pin 40 | RF1/AN17/CPP2 — GPIO RF1 / ADC ch17 / charge pump 2 |
| Pin 41 | RF2/AN18 — GPIO RF2 / ADC ch18 |
| Pin 42 | RF3/AN19 — GPIO RF3 / ADC ch19 |
| Pin 43 | RF4/AN20 — GPIO RF4 / ADC ch20 |
| Pin 44 | RF5/AN21 — GPIO RF5 / ADC ch21 |
| Pin EP | EP (Exposed Pad) — Must be soldered to PCB ground plane for thermal and electrical performance |
Typical Applications
PIC18F45K22-E/ML is suitable for 7 applications: Industrial Control and HMI, Capacitive Touch User Interface, Battery-Powered Sensor Node, Automotive Body Electronics, USB-to-UART Bridge / Communication Bridge, Small Home Appliance Control (White Goods), IoT Edge Device / Sensor Aggregator.
Industrial Control and HMI
The PIC18F45K22-E/ML's 12-bit ADC with up to 30 channels, three PWM modules, and two EUSART interfaces make it a strong fit for industrial control panels and human-machine interface (HMI) boards. Its 48 MHz core handles real-time control loops for motor and valve actuation while the nanoWatt XLP technology keeps standby current below 50 nA, extending battery life in remote or wireless operator panels. The 36 I/O pins directly drive 7-segment displays, keypads, and status LEDs without external logic. Hardware quadrature encoder support via the CCP/ECCP modules simplifies integration with optical encoder wheels in process control applications. Designers should leverage the internal oscillator plus PLL to eliminate external crystals and reduce BOM cost.
Recommended
Capacitive Touch User Interface
The integrated Charge Time Measurement Unit (CTMU) and mTouch peripheral library support capacitive touch buttons, sliders, and proximity sensors with no external components beyond the copper pads. With 36 I/O available, the PIC18F45K22-E/ML can manage 12-16 touch electrodes simultaneously while still driving the main system control loop at 12 MIPS. The 12-bit ADC combined with CTMU provides reliable touch detection even under noisy power conditions, and nanoWatt sleep modes allow the touch sensing to remain active in battery-powered remote controls or smart home keypads with multi-year coin-cell life. Designers can implement water-tolerant touch using Microchip's mTouch software libraries.
Recommended
Battery-Powered Sensor Node
nanoWatt XLP technology is the headline reason to select the PIC18F45K22-E/ML for battery-powered sensor nodes - sleep currents below 50 nA and 11 nA RTCC operation enable multi-year lifetime on a single CR2032 coin cell. The 2.3 V to 5.5 V supply range covers both 3.3 V and 5 V battery chemistries (2xAA, Li-Ion, regulated 3.3 V) without level shifters. The internal oscillator eliminates external crystal power drain, and the 12-bit ADC can directly digitize sensor outputs (temperature, humidity, pressure) with no external signal chain. A typical 1 Hz sample rate with 99.9% sleep duty cycle yields single-digit microamp average current for years of unattended operation in environmental monitoring, smart agriculture, or asset tracking deployments.
Recommended
Automotive Body Electronics
The -E temperature grade qualifies the PIC18F45K22-E/ML for automotive body and interior applications such as seat controllers, mirror adjustment, lighting modules, and HVAC actuators. With 12-bit ADC and three PWM outputs it can drive LED backlighting, dimming channels, and brushed motor control with hardware current sensing via the on-chip comparators. The two EUSARTs support LIN bus master/slave communication for body-electronics networks, with the auto-baud feature simplifying LIN stack development. Designers should note that for OEM safety-critical or full AEC-Q100 deployments the automotive-grade derivatives with explicit qualification should be specified; the /ML package itself is widely adopted across automotive-adjacent consumer products.
Recommended
USB-to-UART Bridge / Communication Bridge
While the PIC18F45K22-E/ML does not include native USB, two EUSART peripherals combined with the MSSP (SPI/I2C) channels make it an excellent host-side bridge controller for industrial gateways, debug loggers, and sensor aggregators. The 12 MIPS performance is sufficient to handle multi-protocol packet routing, while 1.5 KB SRAM accommodates practical receive buffers for slow-speed UART streams. Adding an external FTDI FT230XS-R converts USB to UART and the PIC handles protocol translation, framing, and store-and-forward buffering. This topology is common in legacy industrial equipment migration where RS-232/RS-485 endpoints must be exposed to modern USB hosts.
Recommended
Small Home Appliance Control (White Goods)
The PIC18F45K22-E/ML's combination of 12-bit ADC, three PWM channels, and 36 I/O pins suits washing machine controllers, dishwasher HMIs, microwave ovens, and other small white goods where cost, low power, and robust analog performance are key. The internal oscillator eliminates external crystals to minimize BOM cost, and the 5 V native supply directly drives TRIAC/relay drive circuits for mains switching. nanoWatt sleep modes reduce standby power below 0.5 W to comply with energy-saving regulations. The 12-bit ADC achieves adequate resolution for thermistor-based temperature sensing in ovens and water heaters, while ECCP PWM provides controlled soft-start for universal motors in mixers and pumps.
Recommended
IoT Edge Device / Sensor Aggregator
The PIC18F45K22-E/ML sits well in IoT edge devices where 8-bit processing is sufficient for sensor aggregation, thresholding, and pre-processing before forwarding to a host MCU or wireless module. The 32 KB Flash stores both application code and protocol stacks, while 1.5 KB SRAM is ample for buffering small data frames. The two MSSP peripherals can simultaneously host an I2C sensor array and an SPI wireless module (e.g., a LoRa or sub-GHz transceiver), and the nanoWatt XLP current consumption supports battery-powered deployments. Designers can integrate the CTMU to add capacitive wake-up buttons or sealed enclosure sensors without additional components, while the extended -40C to +125C range supports outdoor and industrial edge nodes.
Recommended
Recommended Products Summary
Engineering reference data for PIC18F45K22-E/ML — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC18F45K22-I/ML | PIC18F46K22-I/ML | PIC18F44K22-I/ML | PIC18F43K22-I/ML |
|---|---|---|---|---|---|
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Package | QFN-44 (8x8 mm) | QFN-44 (8x8 mm) - same | QFN-44 (8x8 mm) - same | QFN-44 (8x8 mm) - same | QFN-44 (8x8 mm) - same |
| Flash Memory | 32 KB | 32 KB | 64 KB | 16 KB | 8 KB |
| SRAM | 1536 bytes | 1536 bytes | 1536 bytes | 1536 bytes | 1536 bytes |
| EEPROM | 256 bytes | 256 bytes | 256 bytes | 256 bytes | 256 bytes |
| Maximum CPU Speed | 48 MHz (12 MIPS) | 48 MHz (12 MIPS) | 48 MHz (12 MIPS) | 48 MHz (12 MIPS) | 48 MHz (12 MIPS) |
| Temperature Range | -40C to +125C (Extended) | -40C to +85C (Industrial) | -40C to +85C (Industrial) | -40C to +85C (Industrial) | -40C to +85C (Industrial) |
| ADC Resolution | 12-bit | 12-bit | 12-bit | 12-bit | 12-bit |
| I/O Pins | 36 | 36 | 36 | 36 | 36 |
Key Differentiators
- Extended temperature grade for industrial / automotive-adjacent applications (vs PIC18F45K22-I/ML)
- Largest Flash in the K22 QFN-44 family at 32 KB (vs PIC18F44K22-I/ML)
- CTMU and mTouch capacitive sensing integrated (vs PIC18F45Q10-I/ML (newer recommended))
Design Notes
The QFN-44 (8x8 mm) package has a large exposed thermal pad (EP) on the underside that MUST be soldered to a properly-sized PCB ground plane. Microchip application guidance recommends thermal vias under the EP (typically a 4x4 grid of 0.3 mm vias) to conduct heat from the die to internal ground planes. Floating or improperly soldered EP causes the die to overheat at modest loads and degrades electrical performance (jitter, ADC noise). For 4-layer PCBs dedicate the inner-1 layer to a continuous ground pour under the MCU, with the top ground fill stitching around the QFN pads.
Decoupling must be placed directly at the VDD/VSS pin pairs of the PIC18F45K22-E/ML. Use a 100 nF ceramic (X7R) capacitor on each VDD pin (there are two VDD pins on the QFN-44), with a shared 10 uF bulk tantalum or ceramic on the supply rail within 25 mm. Place the 100 nF caps within 2 mm of the IC pin pads to minimize parasitic inductance. The analog supply AVdd (shared with VDD on this family) also benefits from a ferrite bead + 10 uF cap to isolate analog ADC reference noise from digital switching transients. This decoupling scheme supports reliable ADC readings at 12-bit resolution.
The 12-bit ADC on the PIC18F45K22-E/ML achieves best performance when the source impedance is below 5 kOhm and a sample-and-hold acquisition time of at least 1.5 us is configured in the ADC register. For higher-impedance sensor sources add an external op-amp buffer. The ADC reference voltage (VREF+ / VREF-) must be stable - use the internal 1.024 V, 2.048 V, or 4.096 V references for absolute measurements, or an external low-noise reference like MCP1525 for precision. Watch for digital-to-analog crosstalk by routing analog signal traces away from PWM outputs and clock lines; use a guard ring around the analog section tied to ground.
Do not omit the MCLR pull-up resistor on pin 38 (RE3/MCLR/VPP) - Microchip requires a 10 kOhm pull-up to VDD for proper reset behavior. Failing to populate this resistor results in intermittent reset failures or inability to enter ICSP programming mode. Likewise, the PGC/PGD pins (RB6/RB7) should not be strapped to active loads during programming because the ICD needs to drive these lines directly. When using the internal oscillator allow adequate startup time per datasheet section - some peripherals like UART require the oscillator to be stable before peripheral enable. Estimated: typical internal oscillator lock time is 4-8 ms depending on configuration bits.
Compliance Information
RoHS and lead-free per Microchip product page. AEC-Q100 not explicitly qualified per datasheet marking; for OEM automotive deployments select the automotive-grade derivatives. Halogen-free status not stated on product page - set unknown per data rules.
