PIC18F27K40-I/ML - 8-Bit 64MHz 128KB Flash MCU | Microchip
MPN: PIC18F27K40-I/ML ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $2.85 | $2.85 |
| 10 | $2.55 | $25.50 |
| 100 | $2.21 | $221.00 |
| 500 | $1.95 | $975.00 |
| 1,000 | $1.74 | $1,740.00 |
PIC18F27K40-I/ML Overview
An 8-bit microcontroller (MCU) is a single-chip computer that integrates a CPU, RAM, program Flash, and peripherals around an 8-bit data bus. PIC18 K40 devices sit in the hierarchy PIC18F -> 8-bit PIC microcontroller -> PIC MCU family -> embedded microcontroller, balancing low power (XLP technology) with rich peripherals suited to general-purpose 5V applications. This category encompasses devices used where deterministic behavior, simple toolchains, and low system cost outweigh the need for 32-bit throughput.
Key features include 128 KB Flash with self-programmability, 3.7 KB RAM, 1 KB EEPROM, 24 analog-capable digital I/O pins, a 10-bit ADC, up to four PWM outputs, four 8-bit timers plus 3 16-bit timers, and configurable logic cells. The XLP Sleep mode draws extremely low current, enabling battery-powered designs. The 5V-tolerant I/O and wide 2.3V-5.5V supply range cover industrial and consumer rail requirements.
Architecturally, the device employs a C-compiler-optimized RISC core with hardware multiply and a 31-level hardware stack. Bus speed scales up to 64 MHz via a 16 MHz internal oscillator plus 4x PLL, achieving 16 MIPS throughput. The 14-bit instruction set remains compatible with prior PIC18 code, easing migration from older 8-bit designs.
Typical applications include battery-powered sensor hubs, home appliance controls, automotive accessory modules, industrial HMI panels, motor control loops, and USB-to-UART bridges. The combination of XLP low power, large Flash, and CIP peripherals makes it appropriate for designers migrating from legacy PIC16 to PIC18 K40 silicon.
When designing, ensure the exposed thermal pad on the 28-QFN package is soldered to a properly sized ground copper pour for thermal dissipation; otherwise expect elevated junction temperatures at high ambient. Use Microchip's MPLAB X IDE with the XC8 compiler for code generation and debugging via ICSP.
This page consolidates distributor pricing, drop-in alternative mapping, and design notes not found in a single resource - supporting both engineer evaluation and procurement decisions as of 2026-09-27.
Drop-in alternatives for PIC18F27K40-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 PIC18F27K40-I/ML (same form factor and footprint) — differing in Package, ADC, Program Memory (Flash), Core Architecture, Operating Temperature.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PIC18F27K42-I/ML
✅ Drop-In ⚠️ Specs Unverified✓ In Stock
$1.85 / Unit
View Datasheet →PIC18F26K40-I/ML
✅ Drop-In ⚠️ Specs Unverified✓ In Stock
$1.78 / Unit
View Datasheet →PIC18F27K40T-I/ML
✅ Drop-In ⚠️ Specs Unverified✓ In Stock
$1.95 / Unit
View Datasheet →PIC18F27K40-I/SP
✅ Drop-In ⚠️ Specs Unverified✓ In Stock
$2.45 / Unit
View Datasheet →PIC18F26Q43-I/SS
✅ Drop-In✓ In Stock
$1.38 / Unit
View Datasheet →PIC18F27K40-I/ML Maximum Ratings & Electrical Characteristics
| Core Architecture | PIC18 8-bit RISC |
| Program Memory (Flash) | 128 KB (64K x 16) |
| EEPROM | 1 KB |
| Maximum CPU Speed | 64 MHz (16 MIPS) |
| Supply Voltage | 2.3 V to 5.5 V |
| I/O Pins | 24 |
| ADC | 10-bit |
| Timers | 4 x 8-bit + 3 x 16-bit |
| PWM Channels | Up to 4 |
| Operating Temperature | -40 C to +85 C (Industrial - I) |
| Package | 28-QFN (6x6 mm) with Exposed Pad (ML) |
| Mounting Type | Surface Mount |
| RoHS Status | Compliant |
PIC18F27K40-I/ML Pin Configuration
| Pin 1 | RA2 — Digital I/O / analog-capable |
| Pin 2 | RA3 — Digital I/O / analog-capable |
| Pin 3 | RA4 — Digital I/O / analog-capable |
| Pin 4 | RA5 — Digital I/O / analog-capable |
| Pin 5 | VDD — Positive power supply 2.3V-5.5V |
| Pin 6 | VSS — Ground reference |
| Pin 7 | OSC1/CLKI/RA7 — Crystal input or digital I/O |
| Pin 8 | OSC2/CLKO/RA6 — Crystal output or digital I/O |
| Pin 9 | RC0 — Digital I/O |
| Pin 10 | RC1 — Digital I/O |
| Pin 11 | RC2 — Digital I/O |
| Pin 12 | RC3 — Digital I/O |
| Pin 13 | RC4 — Digital I/O |
| Pin 14 | RC5 — Digital I/O |
| Pin 15 | RC6 — Digital I/O |
| Pin 16 | RC7 — Digital I/O |
| Pin 17 | RB7 — Digital I/O |
| Pin 18 | RB6 — Digital I/O |
| Pin 19 | RB5 — Digital I/O |
| Pin 20 | RB4 — Digital I/O |
| Pin 21 | RB3 — Digital I/O |
| Pin 22 | RB2 — Digital I/O |
| Pin 23 | RB1 — Digital I/O |
| Pin 24 | RB0 — Digital I/O |
| Pin 25 | VDD — Positive power supply (second rail) |
| Pin 26 | VSS — Ground reference (second rail) |
| Pin 27 | RA0 — Digital I/O / analog-capable / ICD test |
| Pin 28 | RA1 — Digital I/O / analog-capable |
Typical Applications
PIC18F27K40-I/ML is suitable for 6 applications: Battery-Powered Sensor Hub, Home Appliance Control Panel, Automotive Accessory Module (Body Electronics), Industrial HMI / Display Controller, USB HID Bridge / UART Translator, SMPS / LED Lighting Controller.
Battery-Powered Sensor Hub
The PIC18F27K40-I/ML suits battery-powered sensor hubs because its XLP Sleep current draws sub-uA power while the CLC handles event triggering without waking the CPU. With 128 KB Flash the device can support multi-protocol sensor stacks including SPI-driven accelerometers and I2C temperature sensors through a single chip. Its 2.3-5.5V supply range accepts Li-ion, coin-cell, and energy-harvested sources. The 64 MHz CPU clock lets you process sensor data within short active windows to return quickly to sleep, maximizing average battery life in remote IoT edge nodes.
Recommended
Home Appliance Control Panel
For washing machine, dishwasher, or microwave control panels, the PIC18F27K40-I/ML provides 24 I/O to drive seven-segment displays, button matrices, and triac outputs through the CWG peripheral. The 10-bit ADC reads sensor inputs for water level or humidity measurements with adequate resolution. With 128 KB Flash the firmware can include multi-language UI strings and complex state machines. The 5V-tolerant I/O interfaces directly with legacy appliance drivers without level shifting.
Recommended
Automotive Accessory Module (Body Electronics)
In automotive interior accessory modules such as seat controllers or HVAC panel interfaces, the PIC18F27K40-I/ML serves through Microchip's automotive-grade PIC18F27K40-E/ML extended-temperature variant. The CWG peripheral generates complementary PWM for LED backlight dimming with programmable dead-band. The 16-bit timers provide accurate PWM for motor control of small fans. Note that the -I grade is not AEC-Q100 qualified; designers targeting AEC-Q100 should select the -E extended or -V automotive qualified variants from the same K40 family.
Recommended
Industrial HMI / Display Controller
In industrial HMI panels the PIC18F27K40-I/ML drives character or small graphic LCDs through SPI while its PWM peripherals control backlight brightness. The CRC module validates data integrity on communication lines, critical in electrically noisy industrial environments. With 128 KB Flash, designers can implement full menu systems and modbus RTU protocol stacks. The hardware CIPs minimize firmware complexity by handling communication timing autonomously, freeing CPU cycles for display refresh and user input handling.
Recommended
USB HID Bridge / UART Translator
Although the PIC18F27K40-I/ML lacks native USB, the device fits well as a UART-to-SPI/I2C translator that pairs with an external USB-to-UART bridge. Its 128 KB Flash accommodates HID descriptor tables and command parsers when used as an embedded host. The hardware CLC can pre-process incoming data streams without CPU wake-up. For pure USB-MCU designs, the Microchip PIC18F25K50 / PIC18F27J53 family provides native USB in the same 28-QFN footprint.
Recommended
SMPS / LED Lighting Controller
In digital LED controllers the PIC18F27K40-I/ML generates WS2812-style timing via DMA-assisted SPI or through the CWG peripheral, offloading pulse generation from the CPU. The 16-bit timer feeds PWM outputs to drive LED strings with high resolution dimming. Its 5V-tolerant I/O allows direct interfacing with high-brightness LED drivers. The hardware CRC validates long LED data streams in real time. With 128 KB Flash and 64 MIPS throughput, the device manages hundreds of LEDs with smooth color transitions.
Recommended
Recommended Products Summary
Engineering reference data for PIC18F27K40-I/ML — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC18F27K42-I/ML | PIC18F26K40-I/ML | PIC18F27K40T-I/ML | PIC18F26Q43-I/SS |
|---|---|---|---|---|---|
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Package | 28-QFN (6x6) | 28-QFN (6x6) - same | 28-QFN (6x6) - same | 28-QFN (6x6) - same | 28-SSOP - different |
| Flash Memory | 128 KB | 128 KB | 64 KB (-50%) | 128 KB | 64 KB (-50%) |
| Max CPU Speed | 64 MHz / 16 MIPS | 64 MHz / 16 MIPS | 64 MHz / 16 MIPS | 64 MHz / 16 MIPS | 64 MHz / 16 MIPS |
| Core Family | PIC18 K40 | PIC18 K42 | PIC18 K40 | PIC18 K40 | PIC18 Q43 |
| Supply Voltage | 2.3V to 5.5V | 2.3V to 5.5V | 2.3V to 5.5V | 2.3V to 5.5V | 2.3V to 5.5V |
| AEC-Q100 Qualified | No (-I industrial grade) | No | No | No | No |
Key Differentiators
- Core Independent Peripherals (CIPs) (vs PIC16F1825)
- XLP eXtreme Low Power technology (vs PIC18F26K22)
- Large program memory within 28-QFN (vs PIC18F25K50)
Design Notes
The 28-QFN (6x6 mm) package with exposed pad (ML) requires the central thermal pad to be soldered to a ground copper pour for thermal dissipation. Per the Microchip datasheet, recommended minimum copper area is 30 mm squared on the top layer with at least 4 thermal vias connecting to inner planes. Without adequate thermal connection the device may throttle or fail under heavy ADC sampling and constant PWM output. Estimated: at 50 MHz CPU + 5 peripherals active continuously at 5V, internal dissipation remains well under 200 mW but junction temperature rise depends heavily on copper layout.
Place the 100 nF bypass capacitor within 5 mm of each VDD pin, with the shortest possible trace to VSS. The PIC18F27K40 has dual VDD/VSS pairs (pins 5/6 and 25/26), and each requires its own local decoupling. Use a 10 uF bulk capacitor near the IC. For ADC accuracy, route analog inputs (RA0-RA5) perpendicular to high-frequency traces and provide a separate AVSS connection at pin 6 when used. Reference Microchip application note AN2510 for optimal MCU PCB layout techniques.
Do not rely on the internal oscillator for USB or CAN communication due to USB clock tolerance limits exceeding 0.25 percent. Use an external crystal for any timing-sensitive communication protocol. When migrating from older PIC18F devices, note that the K40 family introduces CLC and CWG peripherals with new register names; existing PIC18F code must re-map interrupt vectors. Also note the configuration words are different from legacy PIC18F and require fresh settings in the IDE.
Enable XLP Sleep modes via the PMD and PWMEN registers before deployment in battery applications. The PIC18F27K40's Idle and Sleep current drops to nanoamp range with peripherals disabled. Estimated: at 3V supply with all peripherals off, Sleep I/O leakage is typically below 1 uA. Always ground unused I/O via WPU or set them as digital outputs to avoid floating pin current leakage. Use the PPS (Peripheral Pin Select) module carefully - misconfiguring outputs to inactive PPS pins leaves outputs floating.
Compliance Information
RoHS compliant per Microchip product page. Industrial -I grade is not AEC-Q100 qualified; for automotive use consider the -E extended or dedicated AEC-Q100 K40 variants.
