PIC18LF27K40T-I/ML - 128KB Flash 8-bit XLP MCU | Microchip
MPN: PIC18LF27K40T-I/ML ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $2.93 | $2.93 |
| 10 | $2.74 | $27.40 |
| 100 | $2.41 | $241.00 |
| 500 | $2.18 | $1,090.00 |
| 1,000 | $1.96 | $1,960.00 |
| 1,600 | $1.85 | $2,960.00 |
PIC18LF27K40T-I/ML Overview
A microcontroller (MCU) is a single-chip computer that integrates a CPU core, non-volatile program memory (Flash), volatile working memory (RAM), EEPROM for data retention, and a rich peripheral set into one IC. The PIC18F/LF family uses Microchip's enhanced 8-bit modified Harvard architecture, sitting between simple 8-bit controllers (PIC10/12/16) and 16-bit dsPIC devices in Microchip's lineup. The XLP (eXtreme Low Power) technology branch of PIC18 specifically targets battery-powered and energy-harvesting designs, where nanoWatt sleep currents and active-mode efficiency determine battery life.
The PIC18LF27K40T-I/ML operates from 1.8 V to 3.6 V, distinguishing the LF (low-voltage F) variant from the standard F variant that runs up to 5.5 V. Core Independent Peripherals (CIPs) such as CWG, CRC/Memory Scan, and ZCD can execute complex timing, signal generation, and safety functions in hardware without CPU intervention, reducing firmware complexity and power consumption. PPS allows most digital peripherals to be remapped to a wide range of I/O pins, simplifying PCB routing and BOM reuse across board variants.
Typical applications include IoT sensor nodes, battery-powered instrumentation, low-energy wireless controllers (LoRa, Sub-GHz, BLE front-ends), HVAC and building automation, white-goods user interfaces, and general-purpose embedded control. The combination of 128 KB Flash and PPS also makes the part well-suited to designs where firmware is still evolving during product validation.
When designing with the LF variant, ensure the supply stays within the 1.8 V to 3.6 V window - the part will not survive a 5 V input. A 0.1 uF decoupling capacitor placed within a few millimeters of the VDD pin is required, plus a bulk capacitor on the analog supply if the ADC2 is in use. Watch the QFN exposed pad: it must be soldered to the ground plane for thermal dissipation and electrical reference.
This page synthesizes distributor pricing, drop-in pin-compatible alternatives, application notes, and PCB design considerations beyond the raw datasheet summary, giving an engineer a complete decision snapshot for a 28-pin VQFN PIC18 design.
Drop-in alternatives for PIC18LF27K40T-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 PIC18LF27K40T-I/ML (same form factor and footprint) — differing in ADC, Operating Temperature, Package, Core, I/O Pins.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PIC18F27K40T-I/ML
✅ Drop-In✓ In Stock
$1.95 / Unit
View Datasheet →PIC18LF27K40-I/ML
✅ Drop-In✓ In Stock
$1.18 / Unit
View Datasheet →PIC18LF26K40T-I/ML
✅ Drop-In✓ In Stock
$1.39 / Unit
View Datasheet →PIC18LF27K40-E/ML
✅ Drop-In📋 Reference alternative (not in catalog)
PIC18LF27K40T-I/ML Maximum Ratings & Electrical Characteristics
| Core | PIC18 8-bit RISC |
| Family | PIC18 XLP |
| Program Memory (Flash) | 128 KB (64K x 16) |
| Data Memory (RAM) | 4 KB |
| Data EEPROM | 1 KB |
| Maximum CPU Frequency | 64 MHz |
| Operating Voltage Range | 1.8 V to 3.6 V |
| I/O Pins | 25 |
| ADC | 10-bit ADC2 with Hardware CVD |
| DAC | 5-bit DAC |
| Comparators | 2 |
| PWM / CCP | CCP/PWM channels |
| Communication | EUSART, SPI, I2C |
| Package | 28-QFN (VQFN, 6x6 mm) |
| Mounting Type | Surface Mount |
| Operating Temperature | -40C to +85C (Industrial, 'I') |
| Packing Media | Tape and Reel (1600/reel) |
| Special Features | CWG, WWDT, CRC/Memory Scan, ZCD, PPS, HLT |
| RoHS Status | Compliant |
| Country of Origin | Thailand |
PIC18LF27K40T-I/ML Pin Configuration
| Pin 1 | RA2 — Port A bit 2 (digital I/O, analog input) |
| Pin 2 | RA3 — Port A bit 3 (digital I/O, analog input) |
| Pin 3 | RA4 — Port A bit 4 (digital I/O, analog input) |
| Pin 4 | RA5 — Port A bit 5 (digital I/O, analog input) |
| Pin 5 | RA6 — Port A bit 6 (digital I/O, analog input, OSC2) |
| Pin 6 | RA7 — Port A bit 7 (digital I/O, analog input, OSC1) |
| Pin 7 | VSS — Ground reference |
| Pin 8 | VDD — Positive supply (1.8 V to 3.6 V) |
| Pin 9 | RA0 — Port A bit 0 (digital I/O, analog input) |
| Pin 10 | RA1 — Port A bit 1 (digital I/O, analog input) |
| Pin 11 | RB0 — Port B bit 0 (digital I/O, analog input, interrupt-on-change) |
| Pin 12 | RB1 — Port B bit 1 (digital I/O, analog input, interrupt-on-change) |
| Pin 13 | RB2 — Port B bit 2 (digital I/O, analog input, interrupt-on-change) |
| Pin 14 | RB3 — Port B bit 3 (digital I/O, analog input, interrupt-on-change) |
| Pin 15 | RB4 — Port B bit 4 (digital I/O, analog input, interrupt-on-change) |
| Pin 16 | RB5 — Port B bit 5 (digital I/O, analog input, interrupt-on-change) |
| Pin 17 | RB6 — Port B bit 6 (digital I/O, ICDCLK) |
| Pin 18 | RB7 — Port B bit 7 (digital I/O, ICDDAT) |
| Pin 19 | VSS — Ground reference (digital) |
| Pin 20 | VDD — Positive supply (digital core) |
| Pin 21 | RC0 — Port C bit 0 (digital I/O, analog input) |
| Pin 22 | RC1 — Port C bit 1 (digital I/O, analog input) |
| Pin 23 | RC2 — Port C bit 2 (digital I/O, analog input) |
| Pin 24 | RC3 — Port C bit 3 (digital I/O, analog input) |
| Pin 25 | RC4 — Port C bit 4 (digital I/O, analog input) |
| Pin 26 | RC5 — Port C bit 5 (digital I/O, analog input) |
| Pin 27 | RC6 — Port C bit 6 (digital I/O, analog input) |
| Pin 28 | RC7 — Port C bit 7 (digital I/O, analog input) |
Typical Applications
PIC18LF27K40T-I/ML is suitable for 6 applications: IoT Sensor Node Controller, Battery-Powered Instrumentation, HVAC and Building Automation Controls, White Goods and Appliance User Interface, Low-Energy Wireless Front-End, General-Purpose Embedded Control.
IoT Sensor Node Controller
The PIC18LF27K40T-I/ML fits IoT sensor nodes because its XLP nanoWatt technology drives sleep currents into the nA range, while 128 KB Flash holds substantial protocol stacks (LoRaWAN, BLE HCI, MQTT-SN). The 1.8 V-3.6 V supply pairs directly with a Li-ion battery or 3.3 V LDO without a regulator drop-out. Peripheral Pin Select (PPS) lets one MCU design support multiple daughter-card variants without re-spinning the board, reducing time-to-market for IoT OEMs building a product family.
Recommended
Battery-Powered Instrumentation
Battery-powered instrumentation such as handheld multimeters, dataloggers, and portable environmental monitors benefits from the LF variant's 1.8 V-3.6 V operation on 2xAA or Li-ion chemistries. The 10-bit ADC2 with hardware CVD enables capacitive touch buttons or ratiometric sensor reads without CPU wakeup. Combined with the 5-bit DAC for sensor bias and 2 comparators for threshold detection, the PIC18LF27K40T-I/ML lets designers build a complete instrument frontend on a single 28-QFN.
Recommended
HVAC and Building Automation Controls
HVAC zone controllers, smart thermostats, and building-automation nodes run on the PIC18LF27K40T-I/ML because of its industrial -40C to +85C temperature range, robust 5V-tolerant I/O (when paired with PIC18F variant), and Core Independent Peripherals (CWG, ZCD, CRC). Zero-Cross Detect (ZCD) simplifies AC line triac driving for thermostats, while CWG generates complementary PWM for motor/valve control without CPU loading. PPS allows flexible pin mapping across multiple HVAC board variants.
Recommended
White Goods and Appliance User Interface
White-goods front panels (washing machines, dishwashers, microwave ovens) use the PIC18LF27K40T-I/ML for user-interface control with capacitive touch buttons (Hardware CVD), seven-segment or graphical LCD driving via SPI, and motor-control PWM channels. The 128 KB Flash easily holds an LVGL-style graphics library plus state machine firmware. The 28-QFN compact footprint fits behind the front panel, and the industrial temperature range survives the appliance thermal environment.
Recommended
Low-Energy Wireless Front-End
Low-energy wireless front-ends for Sub-GHz, LoRa, BLE modules, or proprietary RF stacks use the PIC18LF27K40T-I/ML as the host controller because its EUSART/SPI/I2C interfaces directly to common radio transceivers and the LF variant runs at the same 1.8 V-3.6 V level as the radio IC. CRC/Memory Scan hardware verifies firmware integrity at boot, which is essential for wireless security. 25 I/O supports button/scan matrix plus status LED multiplexing for remote-control designs.
Recommended
General-Purpose Embedded Control
General-purpose embedded controllers such as small motor drivers, sensor hubs, and lighting controllers benefit from the PIC18LF27K40T-I/ML because of its Core Independent Peripherals (CIPs) that handle CWG, CRC/Memory Scan, and Zero-Cross Detect in hardware. Peripheral Pin Select gives layout flexibility for the 25 I/O, letting designers fit the same MCU across multiple product SKUs. The 1.8 V-3.6 V LF range matches modern DC-DC rails without a separate regulator.
Recommended
Recommended Products Summary
Engineering reference data for PIC18LF27K40T-I/ML — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC18F27K40T-I/ML | PIC18LF27K40-I/ML | PIC18LF26K40T-I/ML |
|---|---|---|---|---|
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Package | 28-QFN (6x6 mm) | 28-QFN (6x6 mm) - same | 28-QFN (6x6 mm) - same | 28-QFN (6x6 mm) - same |
| Flash | 128 KB | 128 KB | 128 KB | 64 KB (-50%) |
| RAM | 4 KB | 4 KB | 4 KB | 3.5 KB (-12.5%) |
| Operating Voltage | 1.8 V to 3.6 V | 1.8 V to 5.5 V | 1.8 V to 3.6 V | 1.8 V to 3.6 V |
| CPU Frequency | 64 MHz | 64 MHz | 64 MHz | 64 MHz |
| I/O Pins | 25 | 25 | 25 | 25 |
| ADC | 10-bit ADC2 | 10-bit ADC2 | 10-bit ADC2 | 10-bit ADC2 |
| Temperature Range | -40C to +85C (I) | -40C to +85C | -40C to +85C | -40C to +85C |
Key Differentiators
- Larger Flash and RAM than K26 sibling (vs PIC18LF26K40T-I/ML)
- Low-voltage LF variant for 1.8 V-3.6 V rails (vs PIC18F27K40T-I/ML)
- Industrial -40C to +85C temperature range (vs PIC18LF27K40-E/ML)
Design Notes
Place a 0.1 uF decoupling capacitor within 3 mm of the VDD pin (pin 8 and pin 20) and a 1 uF bulk capacitor on the analog VDD rail if the ADC2 is enabled. The PIC18LF27K40T-I/ML will not tolerate voltages above 3.6 V; if the upstream rail can overshoot during hot-plug events, add a TVS diode or RC snubber. Sleep current is in the nA range with XLP nanoWatt mode, but active current at 64 MHz can reach 15 mA - ensure the source impedance stays below 0.5 ohm to avoid VDD sag.
The QFN exposed thermal pad (EP, pin 29 typically) MUST be soldered to the ground plane, both for thermal dissipation (theta_JA improves from ~80 C/W to ~35 C/W) and for electrical reference. Use at least 4 thermal vias in the EP land pattern to conduct heat to the inner ground plane. Keep the EP clearance to signal traces at least 0.2 mm to prevent solder wicking. Place a 0.1 uF cap within 3 mm of VDD, and keep analog traces away from switching signals crossing the EP.
Take advantage of Peripheral Pin Select (PPS) to route the SPI, I2C, and UART signals to convenient pins, but note that PPS remapping introduces a small propagation delay (typically 1-2 ns) and may require the peripheral to be momentarily disabled during remap. Crystal traces (RA6/RA7 if used) must be short (<10 mm), surrounded by a ground guard, and kept away from PWM outputs to avoid coupling. The analog input traces should be guarded by analog ground (AGND) on both sides for ADC accuracy.
Do not exceed 3.6 V on VDD - the LF variant will suffer Flash damage above this limit. Always configure the brown-out reset (BOR) to a value within the operating range (e.g., 1.8 V minimum). When using the ADC2 with hardware CVD for capacitive touch, calibrate the CVD reference at production to compensate for board parasitic capacitance. The 'T' suffix indicates tape-and-reel packing; if your prototype needs cut-tape, order the non-T variant (PIC18LF27K40-I/ML) instead. Always include a 10 kohm pull-up on MCLR (pin 1 equivalent) for reliable reset.
Compliance Information
RoHS compliant per Microchip product page. Not AEC-Q100 qualified - the K40 family targets industrial/consumer, not automotive. For automotive, Microchip recommends dsPIC33A or PIC18-Q1 variants.
