PIC18LF27K40-E/SO - 128KB Flash 8-bit MCU, 64MHz | Microchip
MPN: PIC18LF27K40-E/SO ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $3.42 | $3.42 |
| 10 | $3.07 | $30.70 |
| 100 | $2.61 | $261.00 |
| 500 | $2.18 | $1,090.00 |
| 1,000 | $1.86 | $1,860.00 |
PIC18LF27K40-E/SO Overview
An 8-bit microcontroller (MCU) is a single-chip computer built around an 8-bit data path, typically integrating a CPU core, non-volatile program memory, volatile RAM, EEPROM, digital I/O and a mix of on-chip peripherals such as ADCs, timers and communication interfaces. The PIC18LF family sits inside Microchip's 8-bit PIC® hierarchy, positioned for cost-sensitive, low-power applications that need more memory and peripherals than baseline PIC10/PIC12/PIC16 parts while retaining the simplicity of an 8-bit C-optimized core.
Key features of the PIC18LF27K40 include Core Independent Peripherals (CIPs) such as the Complementary Waveform Generator (CWG), Windowed Watchdog Timer (WWDT) and CRC/SCAN hardware, plus XLP nanoWatt sleep modes that drop quiescent current to the nanoampere range. The 128 KB Flash supports self-programming and large application code, while the 10-bit ADC with internal channels, the 5-bit DAC and configurable comparators enable closed-loop sensor and motor drive designs without external analog ICs. The 28-SOIC package gives a 0.295" (7.50 mm) wide-body footprint that is hand-solderable and friendly to low-cost two-layer boards.
Typical applications include low-power IoT endpoints, battery-powered sensor nodes, white goods and HVAC control panels, automotive body and lighting modules, and small industrial control boards. Designers select the 'LF' variant specifically because of its lower VDD range (down to 1.8 V) versus the PIC18F27K40, making it compatible with single-cell Li-ion or 2x AA primary cells.
When designing with this MCU, place decoupling capacitors (100 nF plus bulk 1-10 uF) within a few millimetres of VDD pins and route analog references (VREF+/VREF-) as guarded traces away from switching signals. The 'E' suffix denotes the -40 °C to +125 °C extended operating temperature grade suitable for industrial and automotive environments.
Drop-in alternatives for PIC18LF27K40-E/SO — 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 PIC18LF27K40-E/SO (same form factor and footprint) — differing in ADC, Package, Comparators, DAC, EEPROM.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PIC18F27K40-E/SO
✅ Drop-In📋 Reference alternative (not in catalog)
PIC18LF27K40-I/SO
✅ Drop-In✓ In Stock
$2.55 / Unit
View Datasheet →PIC18F27K40-I/SO
✅ Drop-In📋 Reference alternative (not in catalog)
PIC18LF27K40-E/SP
✅ Drop-In✓ In Stock
$1.93 / Unit
View Datasheet →PIC18LF27K40-E/SO Maximum Ratings & Electrical Characteristics
| Core | PIC18 8-bit RISC |
| Family | PIC® XLP™ 18K |
| CPU Speed | 64 MHz (16 MIPS) |
| Program Memory (Flash) | 128 KB (64K x 16) |
| RAM | 4 KB |
| EEPROM | 256 B |
| Supply Voltage (VDD) | 1.8 V to 3.6 V |
| I/O Voltage Tolerance | 5 V tolerant |
| Operating Temperature | -40 °C to +125 °C (E suffix) |
| ADC | 10-bit |
| DAC | 5-bit |
| Comparators | Yes |
| PWM Channels | Yes (CCP + CWG) |
| Watchdog | Windowed WDT (WWDT) |
| CRC / SCAN | Yes |
| Zero-Cross Detect (ZCD) | Yes |
| Package | 28-SOIC (0.295", 7.50 mm width) |
| Mounting Type | Surface Mount |
| MSL Level | 1 (per Microchip SOIC standard) |
| RoHS Status | Compliant |
PIC18LF27K40-E/SO 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) |
| Pin 4 | RA5 — Port A bit 5 (digital I/O) |
| Pin 5 | VSS — Ground reference |
| Pin 6 | RA7 — Port A bit 7 (digital I/O, oscillator) |
| Pin 7 | RA6 — Port A bit 6 (digital I/O, oscillator) |
| Pin 8 | RC0 — Port C bit 0 (digital I/O, analog input) |
| Pin 9 | RC1 — Port C bit 1 (digital I/O, analog input) |
| Pin 10 | RC2 — Port C bit 2 (digital I/O, analog input) |
| Pin 11 | RC3 — Port C bit 3 (digital I/O, analog input) |
| Pin 12 | RC4 — Port C bit 4 (digital I/O) |
| Pin 13 | RC5 — Port C bit 5 (digital I/O) |
| Pin 14 | RC6 — Port C bit 6 (digital I/O, TX) |
| Pin 15 | RC7 — Port C bit 7 (digital I/O, RX) |
| Pin 16 | VSS — Ground reference |
| Pin 17 | RC3 — Not connected (no bond-out on this pin position for 28-SOIC variant - reserved) |
| Pin 18 | RB7 — Port B bit 7 (digital I/O, programming) |
| Pin 19 | RB6 — Port B bit 6 (digital I/O, programming) |
| Pin 20 | RB5 — Port B bit 5 (digital I/O) |
| Pin 21 | RB4 — Port B bit 4 (digital I/O) |
| Pin 22 | RB3 — Port B bit 3 (digital I/O) |
| Pin 23 | RB2 — Port B bit 2 (digital I/O) |
| Pin 24 | RB1 — Port B bit 1 (digital I/O) |
| Pin 25 | RB0 — Port B bit 0 (digital I/O, interrupt) |
| Pin 26 | VDD — Positive supply (1.8 V to 3.6 V) |
| Pin 27 | RA0 — Port A bit 0 (digital I/O, analog input) |
| Pin 28 | RA1 — Port A bit 1 (digital I/O, analog input) |
Typical Applications
PIC18LF27K40-E/SO is suitable for 6 applications: Battery-Powered IoT Sensor Nodes, Home Appliance Control Boards, Automotive Body and Lighting Modules, Industrial Sensor and Transmitter Boards, HVAC and Thermostat Controllers, Consumer Remote Controls and HMI.
Battery-Powered IoT Sensor Nodes
The PIC18LF27K40-E/SO fits battery-powered IoT sensor nodes because its 1.8-3.6 V supply range matches a single Li-ion or 2x AA cell, and its XLP nanoWatt sleep modes drop quiescent current to nanoamperes between ADC samples. The 10-bit ADC, integrated temperature indicator, and 128 KB Flash let designers add sensor calibration, edge filtering and secure OTA-capable boot logic in one chip. With up to 16 MIPS at 64 MHz, the core can wake up, sample, transmit, and return to sleep fast enough to keep average system current well below 100 uA. The 28-SOIC wide-body footprint simplifies two-layer hand-soldered prototype boards for low-volume wireless end nodes.
Recommended
Home Appliance Control Boards
White-goods and small appliance control panels benefit from the PIC18LF27K40-E/SO's Core Independent Peripherals: the CWG generates complementary PWM for motor and triac drive, the comparators provide over-current and zero-cross detection, and the WWDT guards against firmware lock-ups. The 4 KB RAM buffers display and keypad scan tasks while 128 KB Flash holds the user-interface state machine, fault handlers and diagnostic logs. With E-grade -40 to +125 °C operation, the device survives under-hood or compressor-adjacent thermal stress in refrigerators, washing machines and HVAC controllers. The 5 V-tolerant I/O eases direct interfacing to legacy opto-isolated triac drivers.
Recommended
Automotive Body and Lighting Modules
Automotive body controllers, lighting ballasts and small sensor clusters use the PIC18LF27K40-E/SO for its wide -40 to +125 °C temperature range and rich analog integration. The 10-bit ADC reads photodiodes and thermistors, the 5-bit DAC drives LED current references, the CWG produces dimming PWM, and the ZCD module detects AC line transitions for dimmer circuits. While the standard part is not AEC-Q100 qualified, it is widely used in non-safety body modules such as ambient lighting and interior controllers. The LF variant runs from a regulated 3.3 V body supply, simplifying power tree design versus 5 V-only MCUs.
Recommended
Industrial Sensor and Transmitter Boards
Loop-powered 4-20 mA transmitters and small industrial sensor boards use the PIC18LF27K40-E/SO because the LF core runs at 3.3 V from the loop supply, while its 5 V-tolerant I/O interfaces to legacy 5 V analog front ends without level shifters. The 10-bit ADC, internal voltage reference, and comparators enable ratiometric bridge measurements, while the CRC/SCAN hardware provides deterministic memory integrity checks. The integrated temperature indicator adds cold-junction compensation for thermocouple inputs, and the 4 KB RAM supports calibration tables and linearization firmware in C. Industrial 4-20 mA loops often require -40 to +85 °C operation at minimum, which the I-grade variant covers, while E-grade supports harsher enclosures.
Recommended
HVAC and Thermostat Controllers
Wall thermostats and HVAC zone controllers benefit from the PIC18LF27K40-E/SO's combination of low-power sleep, robust analog peripherals and 128 KB Flash for UI graphics state machines. The 10-bit ADC reads onboard NTCs and humidity sensors, the comparators detect line-voltage zero crossings for triac-based damper and blower control, and the CCP/PWM modules generate brushed-motor drive signals. Display and capacitive touch scanning are handled by timers and CWG without burdening the core, keeping the CPU available for communication stacks such as Modbus or BACnet. The wide -40 to +125 °C temperature range tolerates closet and attic installations.
Recommended
Consumer Remote Controls and HMI
Universal remote controls, e-bike dashboards and small consumer HMIs use the PIC18LF27K40-E/SO because the 1.8-3.6 V range lets the device run directly from a single Li-ion or 2x AAA cell, while XLP nanoWatt sleep preserves battery life between button presses. The 128 KB Flash stores LCD fonts, multi-language strings and IR or RF protocol libraries (RC5, NEC, BLE HCI bridges), and the 4 KB RAM buffers display frame buffers and event queues. The ZCD module helps in line-powered dimmer remotes where AC zero-cross timing is required for phase-control commands. The 28-SOIC package is friendly to hand rework for low-volume consumer SKUs.
Recommended
Recommended Products Summary
Engineering reference data for PIC18LF27K40-E/SO — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC18F27K40-E/SO | PIC18LF27K40-I/SO | PIC18F27K40-I/SO | PIC18LF27K40-E/SP |
|---|---|---|---|---|---|
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Package | 28-SOIC (wide-body) | 28-SOIC (wide-body) - same | 28-SOIC (wide-body) - same | 28-SOIC (wide-body) - same | 28-SPDIP (different footprint, schematic-pin compatible) |
| Flash | 128 KB | 128 KB | 128 KB | 128 KB | 128 KB |
| RAM | 4 KB | 4 KB | 4 KB | 4 KB | 4 KB |
| EEPROM | 256 B | 256 B | 256 B | 256 B | 256 B |
| CPU Speed | 64 MHz / 16 MIPS | 64 MHz / 16 MIPS | 64 MHz / 16 MIPS | 64 MHz / 16 MIPS | 64 MHz / 16 MIPS |
| Supply Voltage | 1.8 V to 3.6 V | 2.3 V to 5.5 V (wider by ~30%) | 1.8 V to 3.6 V | 2.3 V to 5.5 V (wider by ~30%) | 1.8 V to 3.6 V |
| Operating Temperature | -40 °C to +125 °C (E) | -40 °C to +125 °C (E) | -40 °C to +85 °C (I, narrower by ~33%) | -40 °C to +85 °C (I, narrower by ~33%) | -40 °C to +125 °C (E) |
Key Differentiators
- Larger Flash than entry-level LF cousins (vs PIC18LF26K42-E/SS)
- Extended temperature range option (vs PIC18LF27K40-I/SO)
- Wide-body SOIC for easier hand rework (vs PIC18LF27K40-E/SS)
Design Notes
Place a 100 nF decoupling capacitor within 5 mm of each VDD/AVDD pin and a bulk 1-10 uF ceramic on the main supply rail. For battery-powered designs using the 'LF' supply range, ensure that the bulk capacitor holds VDD above 1.8 V during peak transmit currents; undershoot below 1.8 V causes brown-out resets.
Route the analog reference (VREF+/VREF-) signals as guarded traces with ground on both sides, and physically separate the analog section from PWM outputs and switching nodes. The 28-SOIC wide-body (0.295", 7.50 mm) package gives sufficient pin pitch for two-layer boards with hand-routed analog guards - critical for 10-bit ADC accuracy in noisy motor-control applications.
Do not assume that the LF and F variants are interchangeable on a populated board: PIC18LF27K40 is rated 1.8-3.6 V while PIC18F27K40 is rated 2.3-5.5 V. Programming voltage (MCLR/VPP) and ICSP timing also differ slightly. Always verify VDDMAX against your supply and ensure unused I/O pins are configured as outputs low or inputs with internal pull-ups to minimize I_leakage in nanoWatt sleep.
At -40 °C to +125 °C ambient operation, the 28-SOIC package dissipates negligible power (<10 mW typical at 64 MHz) but junction temperature must stay below +150 °C. Estimate: at 5 mA active I_DD and 3.3 V supply, dissipation is ~16.5 mW, and the 28-SOIC theta_JA of ~70 °C/W gives a junction rise of ~1.2 °C - well within limits. No heatsink is required.
When driving triac or motor-control outputs via the CWG peripheral, keep the high-current trace short and away from the 10-bit ADC inputs. Place a 100 nF bypass on each VDD pin and reserve a quiet analog ground island for ADC reference and sensor signals, joined at a single point to the digital ground near the MCU VSS pin.
Compliance Information
RoHS and lead-free confirmed per Microchip product page. The standard PIC18LF27K40-E/SO is not AEC-Q100 qualified; for automotive safety-critical designs, consider the PIC18F27K40 automotive-grade variant if available in the same family.
