PIC18LF45K40-I/P - 32KB Flash, 8-Bit MCU, 40-DIP | Microchip
MPN: PIC18LF45K40-I/P ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $2.46 | $2.46 |
| 10 | $2.21 | $22.10 |
| 100 | $1.97 | $197.00 |
| 500 | $1.78 | $890.00 |
| 1,000 | $1.59 | $1,590.00 |
PIC18LF45K40-I/P Overview
What is a PIC18 microcontroller? PIC18 is Microchip's high-performance 8-bit microcontroller family using a RISC modified-Harvard architecture with a 16-bit instruction word. PIC18 devices sit within the broader taxonomy: 8-bit MCU -> microcontroller -> embedded controller -> semiconductor IC. XLP variants such as this LF part add sub-uA sleep currents, nanoWDT-level power-down modes, and active mode currents under 1 mA/MIPS, making them suited to battery-powered and energy-harvesting designs.
Key differentiating features include Core Independent Peripherals such as a Complementary Waveform Generator (CWG), Configurable Logic Cell (CLC), Zero-Cross Detect (ZCD), Windowed Watchdog Timer (WWDT), CRC/SCAN, and 10-bit ADC2 with computation, plus a 5-bit DAC. The device integrates a 36-channel digital-to-analog-aware I/O structure, multiple PWM/CCP/SCCP modules, and hardware math accelerators. These peripherals allow complex timing, motor control, and communication tasks without burdening the CPU.
The architecture combines a 16-bit wide instruction pipeline, hardware multiply, and a flexible oscillator system. XLP technology delivers typically 25 nA sleep current and 500 nA watchdog timer retention current, allowing years of operation from a single coin cell. This combination of low power and rich analog/digital integration differentiates the PIC18LF45K40 from simpler PIC16 cousins.
Typical applications include low-power IoT sensor nodes, battery-backed remote controls, industrial sensor conditioning, smart metering, small appliance controls, and USB-less embedded control where a through-hole DIP package simplifies prototyping and field replacement.
When designing with this part, remember that the LF prefix indicates 3.3V nominal operation (max 3.6V); for 5V-tolerant designs, choose the PIC18F45K40-I/P instead. The -I/P suffix indicates industrial temperature and PDIP-40 package. Decoupling, in-circuit serial programming (ICSP) pins, and unused-pin handling must follow Microchip TB087 and the family datasheet.
This page synthesizes distributor pricing, drop-in alternatives within the same DIP-40 footprint, and practical design notes curated from Microchip application notes, supplementing the manufacturer datasheet.
Drop-in alternatives for PIC18LF45K40-I/P — 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 PIC18LF45K40-I/P (same form factor and footprint) — differing in ADC, Package, Timers, Core, I/O Pins.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PIC18F45K40-I/P
✅ Drop-In📋 Reference alternative (not in catalog)
PIC18LF45K40-I/ML
✅ Drop-In ⚠️ Specs Unverified✓ In Stock
$1.92 / Unit
View Datasheet →PIC18LF45K40-E/PT
✅ Drop-In ⚠️ Specs Unverified✓ In Stock
$1.86 / Unit
View Datasheet →PIC18LF45K22-I/P
✅ Drop-In✓ In Stock
$3.35 / Unit
View Datasheet →PIC18LF45J10-I/P
✅ Drop-In✓ In Stock
$2.95 / Unit
View Datasheet →PIC18LF4520-I/PT
✅ Drop-In✓ In Stock
$5.21 / Unit
View Datasheet →PIC18LF45K40-I/P Maximum Ratings & Electrical Characteristics
| Product Family | PIC18 (8-bit RISC, modified Harvard) |
| Core | PIC18 enhanced 8-bit CPU |
| Operating Voltage (Vdd) | 1.8 V to 3.6 V (LF) |
| Maximum CPU Clock | 64 MHz (16 MIPS via 4x PLL) |
| Program Memory (Flash) | 32 KB (16K x 16 words) |
| Data SRAM | 2 KB |
| Data EEPROM | 256 B |
| I/O Pins | 36 |
| ADC | 10-bit ADC2 with Computation (multiple channels) |
| DAC | 5-bit DAC |
| Comparators | Yes |
| PWM / CCP / SCCP | PWM, CCP, SCCP modules |
| CWG | Complementary Waveform Generator |
| CLC | Configurable Logic Cell |
| ZCD | Zero-Cross Detect |
| WWDT | Windowed Watchdog Timer |
| CRC / SCAN | Hardware CRC and memory SCAN |
| Package | 40-pin PDIP (DIP-40), 0.600 in (15.24 mm) |
| Mounting Type | Through-Hole |
| Temperature Grade | Industrial, -40C to +85C |
| RoHS | Compliant |
PIC18LF45K40-I/P Pin Configuration
| Pin 1 | MCLR/RE3 — Master Clear (reset) input / digital input only on PORTE bit 3 |
| Pin 2 | RA0 — PORTA bit 0 / analog input AN0 |
| Pin 3 | RA1 — PORTA bit 1 / analog input AN1 |
| Pin 4 | RA2 — PORTA bit 2 / analog input AN2 |
| Pin 5 | RA3 — PORTA bit 3 / analog input AN3 / Vref+ |
| Pin 6 | RA4 — PORTA bit 4 / analog input AN4 |
| Pin 7 | RA5 — PORTA bit 5 / analog input AN5 |
| Pin 8 | RA6 — PORTA bit 6 / OSC2 |
| Pin 9 | RA7 — PORTA bit 7 / OSC1 |
| Pin 10 | Vss — Ground reference |
| Pin 11 | VDD — Positive supply voltage |
| Pin 12 | RB0 — PORTB bit 0 / INT0 / analog AN12 |
| Pin 13 | RB1 — PORTB bit 1 / INT1 / analog AN10 |
| Pin 14 | RB2 — PORTB bit 2 / INT2 / analog AN8 |
| Pin 15 | RB3 — PORTB bit 3 / analog AN9 |
| Pin 16 | RB4 — PORTB bit 4 / analog AN11 |
| Pin 17 | RB5 — PORTB bit 5 / analog AN13 |
| Pin 18 | RB6 — PORTB bit 6 / ICSPCLK |
| Pin 19 | RB7 — PORTB bit 7 / ICSPDAT |
| Pin 20 | Vss — Ground reference |
| Pin 21 | VDD — Positive supply voltage |
| Pin 22 | RC0 — PORTC bit 0 |
| Pin 23 | RC1 — PORTC bit 1 |
| Pin 24 | RC2 — PORTC bit 2 |
| Pin 25 | RC3 — PORTC bit 3 / SCL1 |
| Pin 26 | RC4 — PORTC bit 4 / SDA1 |
| Pin 27 | RC5 — PORTC bit 5 |
| Pin 28 | RC6 — PORTC bit 6 / TX1 |
| Pin 29 | RC7 — PORTC bit 7 / RX1 |
| Pin 30 | Vss — Ground reference |
| Pin 31 | VDD — Positive supply voltage |
| Pin 32 | RD0 — PORTD bit 0 |
| Pin 33 | RD1 — PORTD bit 1 |
| Pin 34 | RD2 — PORTD bit 2 |
| Pin 35 | RD3 — PORTD bit 3 |
| Pin 36 | RD4 — PORTD bit 4 |
| Pin 37 | RD5 — PORTD bit 5 |
| Pin 38 | RD6 — PORTD bit 6 |
| Pin 39 | RD7 — PORTD bit 7 |
| Pin 40 | RE0 — PORTE bit 0 / analog AN5 |
| Pin 41 | RE1 — PORTE bit 1 / analog AN6 |
| Pin 42 | RE2 — PORTE bit 2 / analog AN7 |
Typical Applications
PIC18LF45K40-I/P is suitable for 6 applications: Battery-Powered IoT Sensor Node, Industrial Sensor Conditioning & Monitoring, Home Appliance Control Board, Smart Metering & Energy Harvesting, Low-Cost Remote Control / HMI Keypad, Educational & Prototyping Platform.
Battery-Powered IoT Sensor Node
The PIC18LF45K40-I/P's XLP nanoWatt sleep currents (down to tens of nA in deep sleep with WWDT running) and 1.8 V minimum supply make it ideal for coin-cell sensor nodes such as temperature, humidity, or motion loggers that must last years on a single CR2032. The 32 KB Flash and 2 KB RAM easily fit ZigBee/Wi-Fi host-command firmware plus a small RTOS or state-machine scheduler. The 10-bit ADC2 with computation performs oversampling and threshold detection on-chip, offloading the CPU; combined with CLC, the device can wake only on qualified sensor events, eliminating firmware polling. The 64 MHz CPU handles SSL/TLS handshake bursts when the radio wakes. For thermocouple or 4-20 mA loops, the LF voltage range is well suited.
Recommended
Industrial Sensor Conditioning & Monitoring
In a 4-20 mA loop transmitter or PLC analog front-end, the PIC18LF45K40-I/P's 10-bit ADC2 with computation and 5-bit DAC support calibration, linearization, and HART-style signal injection. Operating from industrial 24 V rails stepped to 3.3 V, the LF part's 1.8 V to 3.6 V range accepts common regulated rails directly. The Complementary Waveform Generator (CWG) and PWM modules drive opto-isolated MOSFET gate drivers or solid-state relays. Windowed Watchdog Timer (WWDT) and CRC/SCAN hardware diagnostics meet IEC 61508 SIL-2 plausibility checks for industrial sensor designs. The 36 I/O pins interface to multiplexed sensor matrices, keypads, and segment displays.
Recommended
Home Appliance Control Board
For washing machines, dishwashers, or microwave oven control boards, the PIC18LF45K40-I/P integrates motor control PWM, zero-cross detection (ZCD) for triac phase-angle firing, and CWG for synchronous rectification in switched-mode power stages. The 32 KB Flash fits user-interface state machines plus lookup tables for sensor calibration. Configurable Logic Cell (CLC) builds custom glue logic for safety interlocks without external gates. The industrial -40C to +85C operating range and through-hole PDIP-40 package simplify hand-rework during field service calls. EEPROM supports non-volatile storage of user settings across power cycles.
Recommended
Smart Metering & Energy Harvesting
In electricity, water, or gas meters, the PIC18LF45K40-I/P's XLP nanoWatt technology enables continuous metering from a single battery with 10+ year life. The 10-bit ADC2 samples current shunts or rotary-encoder pulses, while the CLC and ZCD modules detect tamper events such as magnetic interference or reverse rotation. The 32 KB Flash stores load profile logs and TOU tariff tables. Windowed Watchdog Timer (WWDT) and CRC/SCAN detect firmware corruption per IEC 62056-21 meter security. The DIP-40 package supports legacy meter-board designs still in production across many utilities worldwide.
Recommended
Low-Cost Remote Control / HMI Keypad
For TV remotes, garage-door openers, or industrial handheld controllers, the PIC18LF45K40-I/P runs for years on two AAA cells thanks to sub-uA deep sleep with periodic WWDT wake. CWG drives an IR emitter with carrier generation in hardware, freeing firmware for protocol stacks (NEC, RC5, or BLE-modulated). 10-bit ADC2 reads joystick or resistive touch inputs. CLC builds bouncing-free button-debounce logic. The 36 I/O pins interface to a 4x4 matrix keypad, multi-LED indicators, and buzzer driver. The PDIP-40 package is convenient for through-hole prototyping.
Recommended
Educational & Prototyping Platform
Universities and makers favor the PIC18LF45K40-I/P for teaching embedded systems because the 40-pin DIP-40 package fits standard breadboards and ZIF sockets, allowing students to insert/remove the MCU without soldering. MPLAB X IDE with XC8 compiler and the PICkit 4 debugger provide a free development toolchain. The 32 KB Flash is generous for coursework projects: LED matrices, UART demos, I2C sensor reading, PWM motor control, and interrupt-driven state machines. The -I/P industrial grade withstands classroom handling better than commercial grade parts.
Recommended
Recommended Products Summary
Engineering reference data for PIC18LF45K40-I/P — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC18F45K40-I/P | PIC18LF45K22-I/P | PIC18LF45J10-I/P | PIC18LF4520-I/P |
|---|---|---|---|---|---|
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Package | PDIP-40 (DIP-40) | PDIP-40 (DIP-40) - same | PDIP-40 (DIP-40) - same | PDIP-40 (DIP-40) - same | PDIP-40 (DIP-40) - same |
| Flash Memory | 32 KB | 32 KB | 16 KB (-50%) | 32 KB | 32 KB |
| SRAM | 2 KB | 2 KB | 2 KB | 1.5 KB | 1.5 KB |
| Operating Voltage | 1.8 V to 3.6 V | 2.3 V to 5.5 V | 1.8 V to 3.6 V | 2.0 V to 3.6 V | 2.0 V to 5.5 V |
| Max CPU Clock | 64 MHz (16 MIPS) | 64 MHz (16 MIPS) | 64 MHz (16 MIPS) | 40 MHz (10 MIPS) | 40 MHz (10 MIPS) |
| XLP Low-Power | Yes (nanoWatt XLPs) | Yes | Yes (XLP) | No | No |
| Core Independent Peripherals | CWG, CLC, ZCD, CRC/SCAN, WWDT | CWG, CLC, ZCD, CRC/SCAN, WWDT | Reduced (no CLC) | None | None |
| Unit Price (qty 1) | $2.46 | ~$2.50 | ~$2.20 | ~$2.60 | ~$2.80 |
Key Differentiators
- Modern Core Independent Peripherals with XLP low power (vs PIC18LF4520-I/P)
- Higher memory density than K22 family (vs PIC18LF45K22-I/P)
- 3.3 V native operation (vs PIC18F45K40-I/P)
Design Notes
Estimated: at 3.3 V VDD, 64 MHz CPU, full peripheral activity, the PIC18LF45K40-I/P draws approximately 8-10 mA. Sleep current with WWDT and RTCC running is on the order of hundreds of nA; deep sleep with all clocks off drops to single-digit uA. For battery designs, use the XLP configuration bits (IDSLE, IDRUN, VREGPM) to minimize active idle current. Always place a 100 nF decoupling capacitor within 5 mm of each VDD/VSS pair and a bulk 10 uF tantalum or ceramic on the main supply pin to handle PLL-induced transients.
Route the ICSP pins (RB6/ICSPCLK, RB7/ICSPDAT, MCLR) to a 5-pin header footprint with MCLR pulled up via 10 kOhm to VDD and a 100 nF cap to ground for in-circuit programming. Keep the MCLR trace short to avoid noise-induced resets. Place a ferrite bead or 10 Ohm resistor in series with VDD if the board shares a noisy power rail, and add a reverse-polarity protection diode at the input.
Do not exceed 3.6 V on VDD - the LF variant is permanently damaged above this level. Configure unused I/O pins as outputs driving low (never floating) to minimize shoot-through current. Always set the configuration words to disable the watchdog only if the firmware is mature; for new code, keep the WWDT enabled with a long timeout (e.g. 4 s) to catch hangs. Use the ICSP ICDWR bit to protect Flash during debug.
Separate analog and digital ground planes and join them at a single point under the MCU's AGND/AVSS pin. Route analog signals (AN0-AN13) away from digital clocks like PWM or CCP outputs. For ADC2 noise-sensitive measurements, add a small RC filter (1 kOhm + 100 nF) at the analog input. Keep the OSC1/OSC2 crystal traces short (<10 mm) and surround them with a ground guard ring.
Compliance Information
RoHS compliant per Microchip product page; industrial temperature grade -40C to +85C; not AEC-Q100 qualified - choose PIC18F45K40-E/P or similar extended automotive grade for automotive designs
