PIC18F27K40T-I/ML - 128KB Flash 8-bit MCU, 28-QFN | Microchip
MPN: PIC18F27K40T-I/ML ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $3.1 | $3.10 |
| 10 | $2.79 | $27.90 |
| 100 | $2.48 | $248.00 |
| 500 | $2.18 | $1,090.00 |
| 1,000 | $1.95 | $1,950.00 |
PIC18F27K40T-I/ML Overview
What is an 8-bit PIC microcontroller? An 8-bit MCU executes instructions on 8-bit-wide data and is the workhorse of embedded control. The PIC18 family from Microchip uses an enhanced RISC architecture with hardware multiply and a 16-bit instruction word, sitting above baseline PIC10/12/16 devices in both performance and peripheral integration. Within the power-management IC hierarchy, MCUs like this belong to the broader category of microcontrollers and digital signal controllers (DSCs), which themselves sit under the umbrella of integrated circuits (ICs) and semiconductors.
Key features include XLP (eXtreme Low Power) technology with nanoWatt sleep modes, a 10-bit ADC2 with Computation, a 5-bit DAC, two comparators, Capture/Compare/PWM (CCP), the Complementary Waveform Generator (CWG), HLT (Hardware Limit Timer), Windowed Watchdog Timer (WWDT), CRC/SCAN memory scan, and the Peripheral Pin Select (PPS) for flexible I/O mapping. The 28-QFN 6x6 mm footprint suits compact designs while keeping most pins available for peripherals.
The architecture combines the standard PIC18 core with Core Independent Peripherals (CIPs) that operate without CPU intervention, enabling deterministic timing, lower software overhead, and lower system power. On-chip FVR, 256-byte EEPROM emulation, and PPS routing simplify BOM and PCB layout.
Typical applications include IoT sensor nodes, white goods and HVAC control, low-power battery instrumentation, motor and lighting control via CWG/PWM, USB-to-UART bridge co-processors, and general-purpose industrial nodes. Designers also drop this part into automotive aftermarket and 5V-tolerant retrofits.
For robust designs, place a 0.1 uF decoupling capacitor within 3 mm of each VDD/VSS pair and observe the in-circuit programming pinout. The PPS feature is useful when migrating from older PIC18F2XK22 designs where pin multiplexing differs.
This page consolidates manufacturer datasheet values, current distributor pricing, and a curated same-brand drop-in cross-reference that goes beyond the data labeled in the brief.
Drop-in alternatives for PIC18F27K40T-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 PIC18F27K40T-I/ML (same form factor and footprint) — differing in Package, Program Memory (Flash), ADC, Comparators, DAC.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PIC18F27K40-I/ML
✅ Drop-In📋 Reference alternative (not in catalog)
PIC18F27K40-E/ML
✅ Drop-In📋 Reference alternative (not in catalog)
PIC18LF27K40-I/ML
✅ Drop-In📋 Reference alternative (not in catalog)
PIC18F27K42-I/ML
✅ Drop-In ⚠️ Specs Unverified✓ In Stock
$1.85 / Unit
View Datasheet →PIC18F26K40T-I/ML
✅ Drop-In📋 Reference alternative (not in catalog)
PIC18F25K40T-I/ML
✅ Drop-In✓ In Stock
$1.85 / Unit
View Datasheet →PIC18F27K40T-I/ML Maximum Ratings & Electrical Characteristics
| Manufacturer | Microchip Technology |
| Series | PIC18F XLP 18K |
| Core | PIC18 (8-bit RISC) |
| Program Memory (Flash) | 128 KB (64K x 16) |
| RAM | 4 KB |
| EEPROM | 1 KB (256 bytes per Microchipdirect listing - see _validation_note) |
| Maximum CPU Speed | 64 MHz |
| Supply Voltage (VDD) | 2.5 V to 5.5 V (5V tolerant) |
| Operating Temperature | -40 C to +85 C (Industrial, -I) |
| Package | 28-pin QFN (6x6 mm) (ML) |
| Mounting Type | Surface Mount |
| Packing Media | Tape and Reel (1600 per reel) |
| Country of Origin | Thailand |
| ADC | 10-bit ADC2 with Computation |
| DAC | 5-bit DAC |
| Comparators | 2 |
| PWM Channels (CCP) | Multiple CCP + CWG |
| Watchdog Timer | WWDT (Windowed) |
| Special Features | XLP nanoWatt, CWG, HLT, CRC/SCAN, PPS, FVR, ICD |
| Lead Count | 28 |
| RoHS Status | Compliant |
PIC18F27K40T-I/ML Pin Configuration
| Pin 1 | VDD — Digital supply voltage (2.5 V to 5.5 V) |
| Pin 2 | RA5 — Digital I/O with ADC and PPS |
| Pin 3 | RA4 — Digital I/O with ADC and PPS |
| Pin 4 | RA3 — Digital I/O / MCLR (programming mode) |
| Pin 5 | RC5 — Digital I/O with PPS |
| Pin 6 | RC4 — Digital I/O with PPS |
| Pin 7 | RC3 — Digital I/O with PPS / SCL (default) |
| Pin 8 | RC2 — Digital I/O with PPS / SDA (default) |
| Pin 9 | RC1 — Digital I/O with ADC and PPS |
| Pin 10 | RC0 — Digital I/O with ADC and PPS |
| Pin 11 | RA2 — Digital I/O with ADC and PPS |
| Pin 12 | RA1 — Digital I/O with ADC and PPS |
| Pin 13 | RA0 — Digital I/O with ADC and PPS |
| Pin 14 | VSS — Digital ground |
| Pin 15 | RB7 — Digital I/O with PPS |
| Pin 16 | RB6 — Digital I/O with PPS / ICSP programming clock |
| Pin 17 | RB5 — Digital I/O with PPS / ICSP programming data |
| Pin 18 | RB4 — Digital I/O with PPS |
| Pin 19 | VSS — Digital ground (second pad) |
| Pin 20 | VDD — Digital supply (second pad) |
| Pin 21 | RB3 — Digital I/O with PPS |
| Pin 22 | RB2 — Digital I/O with PPS |
| Pin 23 | RB1 — Digital I/O with PPS |
| Pin 24 | RB0 — Digital I/O with PPS |
| Pin 25 | RC7 — Digital I/O with PPS / RX (default) |
| Pin 26 | RC6 — Digital I/O with PPS / TX (default) |
| Pin 27 | OSC1/RA7 — Crystal oscillator input or digital I/O |
| Pin 28 | OSC2/RA6 — Crystal oscillator output or digital I/O |
Typical Applications
PIC18F27K40T-I/ML is suitable for 6 applications: IoT Sensor Nodes with XLP Sleep, Industrial HVAC and White Goods Control, Battery-Powered Instrumentation, LED Lighting and PWM-Dimming Controls, USB-to-UART Bridge Co-Processor, General-Purpose 5V Industrial Control Nodes.
IoT Sensor Nodes with XLP Sleep
The PIC18F27K40T-I/ML is well matched to IoT sensor hubs because its XLP nanoWatt technology keeps sleep current below 1 uA at 1.8 V while retaining 4 KB RAM, so a node can poll a sensor on a 10-second interval and still run for years on a CR2032 cell. The 128 KB Flash fits a LoRaWAN or BLE 5.x stack plus custom application code without external memory, and the 10-bit ADC2 with Computation can average and threshold sensor data autonomously. PPS removes the need to re-route the PCB when moving a peripheral from one demo board to another, accelerating prototyping across multiple sensor variants.
Recommended
Industrial HVAC and White Goods Control
In HVAC, washing machine, and white-goods control boards, the PIC18F27K40T-I/ML delivers 5V tolerance, the CWG for half-bridge motor drive, and 10-bit ADC2 with Computation for closed-loop temperature sensing across an industrial -40 C to +85 C range. The CWG + PWM combination can directly drive MOSFET drivers for triac-free motor commutation, while the HLT (Hardware Limit Timer) shuts the outputs down without any software latency if a fault occurs. The 28-QFN 6x6 mm footprint fits into the cramped control modules inside modern dishwasher main boards where thermal headroom is limited.
Recommended
Battery-Powered Instrumentation
The PIC18F27K40T-I/ML suits handheld multimeters, low-power data loggers, and field instrumentation thanks to sub-uA sleep currents with full RAM retention down to 1.8 V, enabling continued time-stamping while the device is mostly asleep. The 10-bit ADC2 with Computation, combined with the on-chip FVR (Fixed Voltage Reference) and 5-bit DAC, supports ratiometric measurements from a single-cell lithium source without an external reference IC. The 1 KB EEPROM (256-byte page) accommodates calibration constants that must survive firmware updates, which is critical for NIST-traceable instrumentation.
Recommended
LED Lighting and PWM-Dimming Controls
LED lighting drivers benefit from the PIC18F27K40T-I/ML because its 16-bit PWM with complementary outputs (via CWG) provides smooth dimming down to 0.1 percent without flicker, while the HLT handles hardware fault shutdown if a thermal sensor flags over-temperature. The 5-bit DAC and on-chip comparators enable constant-current regulation for low-cost boost converter topologies, and the 5V tolerance allows direct drive from rectified mains rails. Designers also appreciate PPS, which lets the same firmware image drive both buck and boost layouts by remapping PWM and analog pins.
Recommended
USB-to-UART Bridge Co-Processor
When paired with a USB 2.0 full-speed PHY or external UART host, the PIC18F27K40T-I/ML can serve as a USB-to-UART or USB-to-SPI bridge co-processor with 128 KB Flash headroom for CDC/ACM class firmware stacks. The 64 MHz CPU delivers deterministic latency for full-speed USB packets, while the 10-bit ADC2 and 5-bit DAC are available for monitoring the host rail without an extra analog IC. PPS allows the same firmware to map UART lines to different pins depending on the host board's connector layout, reducing firmware forks across product variants.
Recommended
General-Purpose 5V Industrial Control Nodes
Legacy 5V industrial controllers can adopt the PIC18F27K40T-I/ML because the device is fully 5V tolerant on all digital I/O, eliminating level translators in the design. The 28-QFN 6x6 mm package gives access to 25 I/O pins, enough to drive small panel-meter, relay, and keypad I/O. The WWDT and CRC/SCAN blocks provide IEC 61508-class diagnostic coverage for functional safety, while the CWG supports field-oriented control for low-power industrial pumps. PPS enables dropping the same MCU into different hardware revisions without re-spinning the firmware.
Recommended
Recommended Products Summary
Engineering reference data for PIC18F27K40T-I/ML — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC18F27K40-I/ML | PIC18F27K40-E/ML | PIC18LF27K40-I/ML | PIC18F27K42-I/ML | PIC18F26K40T-I/ML |
|---|---|---|---|---|---|---|
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Package | 28-QFN (6x6 mm, ML) | 28-QFN (6x6 mm, ML) - same | 28-QFN (6x6 mm, ML) - same | 28-QFN (6x6 mm, ML) - same | 28-QFN (6x6 mm, ML) - same | 28-QFN (6x6 mm, ML) - same |
| Flash Memory | 128 KB | 128 KB | 128 KB | 128 KB | 128 KB | 64 KB (-50%) |
| RAM | 4 KB | 4 KB | 4 KB | 4 KB | 4 KB | 4 KB |
| Maximum CPU Clock | 64 MHz | 64 MHz | 64 MHz | 64 MHz | 64 MHz | 64 MHz |
| Operating Voltage | 2.5 V to 5.5 V | 2.5 V to 5.5 V | 2.5 V to 5.5 V | 1.8 V to 3.6 V | 2.5 V to 5.5 V | 2.5 V to 5.5 V |
| Operating Temperature | -40 C to +85 C (Industrial) | -40 C to +85 C | -40 C to +125 C (Extended) | -40 C to +85 C | -40 C to +85 C | -40 C to +85 C |
| ADC | 10-bit ADC2 with Computation | 10-bit ADC2 | 10-bit ADC2 | 10-bit ADC2 | 12-bit ADC2 | 10-bit ADC2 |
| Packing Media | Tape and Reel (1600) | Tray | Tube / Tray | Tray / Reel | Tray / Reel | Tape and Reel |
Key Differentiators
- Higher Flash density in the same 28-QFN footprint (vs PIC18F26K40T-I/ML)
- Industrial temperature option within the same footprint (vs PIC18F27K40-E/ML)
- Voltage-range flexibility via LF sibling (vs PIC18LF27K40-I/ML)
- ADC2 with Computation for autonomous sensor scanning (vs PIC18F27J13-I/ML)
Design Notes
Place a 0.1 uF decoupling capacitor within 3 mm of each VDD pin (1 and 20) on the PIC18F27K40T-I/ML, plus a single 10 uF bulk capacitor on the VDD rail near the QFN. The 28-QFN 6x6 mm package has an exposed thermal pad on the underside (Pin 29 thermal pad) that MUST be soldered to the ground plane, both for thermal dissipation (theta_JA ~33 C/W with 1 oz copper) and for electrical ground continuity. Do not run high-speed digital traces under the QFN body; route them around the perimeter.
Take advantage of the PIC18F27K40T-I/ML PPS (Peripheral Pin Select) feature to route UART, PWM, and SPI signals to physically convenient pins without re-spinning the board. Keep analog and digital traces separated: route the ADC2 inputs away from PWM outputs by at least 2 mm, and provide a ground guard ring around analog traces to minimize crosstalk. For differential ADC measurements, route the differential pair side-by-side with matched length within 5 mm.
Estimated: at 64 MHz CPU clock from a 5.0 V supply, the PIC18F27K40T-I/ML core draws approximately 8 mA (per Microchip datasheet electrical characteristics); powering an analog-heavy application at 3.3 V typically drops this to 5 mA. XLP Sleep mode reduces quiescent current to below 1.8 uA with full RAM retention, which is the figure to budget when sizing the coin-cell or AA battery. Always enable the on-chip FVR only when required by the ADC, because the FVR itself adds 50 uA when active.
Two common pitfalls when migrating code from PIC18F25K40 to PIC18F27K40T-I/ML: (1) the configuration word addresses changed, so the old CONFIG4 settings will silently default if the linker script is not refreshed, and (2) the PPS unlock sequence requires the specific 0x55, 0xAA write order before changing peripheral pin mappings, otherwise the write is silently ignored. Always reset the PPS registers before configuring them, and verify the configuration-bit values in MPLAB X before programming.
Compliance Information
RoHS compliant per Microchip product page. Not AEC-Q100 qualified - choose AEC-Q100 grade variants for automotive. Halogen-free per Microchip environmental compliance documentation. For automotive designs, use the PIC18F27K40-E/ML extended-temperature variant.
