PIC18LF27K42-E/SO - 128KB Flash 8-bit MCU 64MHz 28-SOIC
MPN: PIC18LF27K42-E/SO ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $4.1 | $4.10 |
| 10 | $3.68 | $36.80 |
| 100 | $3.05 | $305.00 |
| 500 | $2.7 | $1,350.00 |
| 1,000 | $2.4 | $2,400.00 |
PIC18LF27K42-E/SO Overview
A microcontroller (MCU) is a single-chip computer that integrates a CPU core, non-volatile program memory, working RAM, and a configurable set of peripheral blocks. In the broader system hierarchy an MCU sits below microprocessors (which need external memory) but above bare digital logic, and the PIC18 family occupies the 8-bit RISC tier of that taxonomy. The 'LF' prefix denotes an extended-voltage variant that supports lower VDD rails than the standard 'F' revision, while 'K42' identifies the specific peripheral generation introduced by Microchip around 2020 with rich core-independent peripherals.
Key features include a 12-bit ADC2 with automated channels scan, a 5-bit DAC, two comparators, an 8-bit timer cluster, PWM, CWG (complementary waveform generator), ZCD (zero-cross detect), DMA, vector interrupts, PPS (peripheral pin select), a WWDT windowed watchdog, and SCAN/CRC for memory integrity checks. Connectivity is covered by UART, SPI, and I2C peripherals, all software-remappable through PPS, which simplifies PCB layout when migrating pin assignments between PIC18 K42 variants.
Typical applications include low-power IoT sensor nodes, battery-powered handheld instruments, LED lighting controllers, and consumer appliance control boards. The XLP (eXtreme Low Power) technology adds IDLE, DOZE, and peripheral-module-disable modes, allowing currents in the nanoampere range during sleep. Designers often pair the LF27K42 with a small LDO, a CR2032 or Li-Ion cell, and a 32.768kHz crystal for RTC-style timing, enabling multi-year battery life on coin cells. The 28-SOIC footprint also eases hand-soldering for prototyping and small-batch production.
When designing with this part, ensure your toolchain targets the K42 family (XC8 2.32 or later with device packs), and verify the PPS mapping carefully during porting from PIC18F to PIC18LF variants. The 'E' temperature grade marks the -40C to +125C industrial range, matching most outdoor and automotive-cabin environments. This page synthesizes distributor pricing, K42-family drop-in alternatives, and practical design notes not found in the manufacturer datasheet.
Drop-in alternatives for PIC18LF27K42-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 PIC18LF27K42-E/SO (same form factor and footprint) — differing in DAC, Package, ADC, Operating Temperature, Comparators.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PIC18F27K42-E/SO
✅ Drop-In📋 Reference alternative (not in catalog)
PIC18LF27K42-I/SO
✅ Drop-In✓ In Stock
$1.78 / Unit
View Datasheet →PIC18LF27K42T-I/SO
✅ Drop-In📋 Reference alternative (not in catalog)
PIC18LF27K40-E/SO
✅ Drop-In✓ In Stock
$1.86 / Unit
View Datasheet →PIC18LF27K42-I/SS
✅ Drop-In✓ In Stock
$2.15 / Unit
View Datasheet →PIC18LF46K42-I/SO
✅ Drop-In📋 Reference alternative (not in catalog)
PIC18LF27K42-E/SO Maximum Ratings & Electrical Characteristics
| Core | PIC18 8-bit RISC |
| Operating Frequency | 64 MHz (max) |
| Instruction Throughput | 16 MIPS |
| Program Memory (Flash) | 128 KB (64K x 16) |
| SRAM | 8 KB |
| EEPROM | 1 KB |
| Operating Voltage (VDD) | 1.8 V to 5.5 V |
| I/O Pins | 24 |
| ADC | 12-bit ADC2 with computation |
| DAC | 5-bit DAC |
| Comparators | 2 |
| Timers | 8-bit and 16-bit timers |
| PWM Channels | Yes (multiple channels) |
| Communication | UART, SPI, I2C |
| Package | 28-pin SOIC (SO) |
| Mounting Type | Surface Mount |
| Operating Temperature | -40C to +125C (E grade) |
| Low-Power Features | XLP: IDLE/DOZE/PMD |
| Watchdog | WWDT (windowed) |
| Peripheral Pin Select | Yes (PPS) |
| DMA | Yes |
| Vectored Interrupts | Yes |
| RoHS Status | Compliant |
PIC18LF27K42-E/SO Pin Configuration
| Pin 1 | RA0/ANA0 — Bidirectional I/O / ADC analog channel 0 |
| Pin 2 | RA1/ANA1 — Bidirectional I/O / ADC analog channel 1 |
| Pin 3 | RA2/ANA2 — Bidirectional I/O / ADC analog channel 2 |
| Pin 4 | RA3/ANA3 — Bidirectional I/O / ADC analog channel 3 / VREF+ |
| Pin 5 | RA4/ANA4 — Bidirectional I/O / ADC analog channel 4 |
| Pin 6 | RA5/ANA5 — Bidirectional I/O / ADC analog channel 5 |
| Pin 7 | RA6/ANA6 — Bidirectional I/O / ADC analog channel 6 |
| Pin 8 | RA7/ANA7 — Bidirectional I/O / ADC analog channel 7 |
| Pin 9 | VSS — Ground reference |
| Pin 10 | RB0/ZCD — Bidirectional I/O / Zero-Cross Detect input |
| Pin 11 | RB1 — Bidirectional I/O |
| Pin 12 | RB2 — Bidirectional I/O |
| Pin 13 | RB3 — Bidirectional I/O |
| Pin 14 | RB4 — Bidirectional I/O |
| Pin 15 | RB5 — Bidirectional I/O |
| Pin 16 | RB6/ICSPCLK — Bidirectional I/O / ICD serial clock |
| Pin 17 | RB7/ICSPDAT — Bidirectional I/O / ICD serial data |
| Pin 18 | VSS — Ground reference (second VSS) |
| Pin 19 | VDD — Positive supply voltage |
| Pin 20 | VDD — Positive supply voltage (second VDD) |
| Pin 21 | RC0 — Bidirectional I/O |
| Pin 22 | RC1 — Bidirectional I/O |
| Pin 23 | RC2 — Bidirectional I/O |
| Pin 24 | RC3 — Bidirectional I/O |
| Pin 25 | RC4 — Bidirectional I/O |
| Pin 26 | RC5 — Bidirectional I/O |
| Pin 27 | RC6/ANA8 — Bidirectional I/O / ADC analog channel 8 |
| Pin 28 | RC7/ANA9 — Bidirectional I/O / ADC analog channel 9 |
Typical Applications
PIC18LF27K42-E/SO is suitable for 7 applications: Battery-Powered IoT Sensor Nodes, Handheld Consumer Appliances, LED Lighting and Driver Controllers, Industrial Sensor Conditioning, Automotive Cabin and Body Modules, Medical Monitoring Devices, Low-Power Communication Gateways.
Battery-Powered IoT Sensor Nodes
The PIC18LF27K42-E/SO is ideal for battery-powered wireless sensor nodes because its 1.8V minimum VDD lets it run from a single alkaline or coin-cell battery while the XLP architecture drives sleep current into the nanoampere range. Its 128KB Flash hosts application code plus a small OTA bootloader, and the 12-bit ADC2 with hardware computation handles thermocouple or strain-gauge conditioning. The integrated DMA offloads sensor capture so the CPU can stay in IDLE mode, extending battery life into multi-year territory on a CR2032.
Recommended
Handheld Consumer Appliances
For handheld kitchen or personal-care appliances, the PIC18LF27K42-E/SO delivers 16 MIPS at 64 MHz which is plenty for capacitive touch decoding, brushless-DC commutation via the CWG peripheral, and indicator LED PWM. The 5.5V upper rail means a single Li-Ion cell can power the MCU directly without an LDO. ZCD (zero-cross detect) simplifies AC-line timing for appliance controls bridged through triacs, while the WWDT and SCAN/CRC blocks ensure IEC 60730 safety compliance.
Recommended
LED Lighting and Driver Controllers
The PIC18LF27K42-E/SO suits multi-channel LED drivers because its multiple PWM outputs and the CWG block produce complementary waveforms with programmable dead-time for synchronous buck/flyback topologies. The 5-bit DAC and two comparators enable closed-loop constant-current regulation without external op-amps, and the DMA can refresh PWM duty cycles autonomously. Running from 1.8V, the MCU can be powered from an auxiliary winding on the LED driver transformer.
Recommended
Industrial Sensor Conditioning
In industrial 4-20 mA loop or 0-10V sensor interfaces, the PIC18LF27K42-E/SO provides a 12-bit ADC2 with computation, hardware averaging, and oversampling for high-noise environments. Its -40C to +125C E-grade temperature range suits outdoor enclosures and factory-floor installations. The 128KB Flash accommodates Modbus RTU or proprietary protocols over UART, and the PPS peripheral pin select lets designers keep the PCB layout compact by remapping UART/SPI/I2C to any I/O pin.
Recommended
Automotive Cabin and Body Modules
Within automotive cabin/body electronics - HVAC controls, seat controllers, interior lighting - the PIC18LF27K42-E/SO handles LIN-bus communication over its UART peripheral and offers PWM for motor or LED driving. Its E-grade -40C to +125C rating matches cabin environments. Although it is not AEC-Q100 qualified, the same die is offered in the PIC18F27K42 automotive grade for designs that need full automotive certification on the same 28-SOIC footprint.
Recommended
Medical Monitoring Devices
For low-power medical monitors such as pulse oximeters, glucose meters, or portable thermometers, the PIC18LF27K42-E/SO provides a 12-bit ADC2 for sensor readout, ample Flash for IEC 62304-compliant firmware, and nanoamp sleep currents for shelf life. Its 28-SOIC package simplifies hand-prototyping and small-batch assembly for medical startups. The WWDT and SCAN/CRC peripherals help satisfy IEC 60601 self-test requirements without an external supervisor.
Recommended
Low-Power Communication Gateways
As the host MCU in sub-GHz or BLE sensor gateways, the PIC18LF27K42-E/SO serves as a power-managed controller that wakes the radio on interrupt, buffers packets, then returns to IDLE. The DMA controller moves UART/SPI data between the radio and RAM without CPU intervention, while PPS lets the designer route signals to convenient PCB locations. Its 1.8V operation is ideal for solar or energy-harvested gateway nodes.
Recommended
Recommended Products Summary
Engineering reference data for PIC18LF27K42-E/SO — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC18F27K42-E/SO | PIC18LF27K42-I/SO | PIC18LF27K42T-I/SO | PIC18LF27K40-E/SO | PIC18LF27K42-I/SS | PIC18LF46K42-I/SO |
|---|---|---|---|---|---|---|---|
| Package | 28-SOIC | 28-SOIC - same | 28-SOIC - same | 28-SOIC - same | 28-SOIC - same | 28-SSOP | 28-SOIC - same |
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Flash Memory | 128 KB | 128 KB | 128 KB | 128 KB | 64 KB | 128 KB | 64 KB |
| SRAM | 8 KB | 8 KB | 8 KB | 8 KB | 4 KB | 8 KB | 4 KB |
| EEPROM | 1 KB | 1 KB | 1 KB | 1 KB | 1 KB | 1 KB | 1 KB |
| Operating Voltage | 1.8 V to 5.5 V | 2.3 V to 5.5 V | 1.8 V to 5.5 V | 1.8 V to 5.5 V | 1.8 V to 5.5 V | 1.8 V to 5.5 V | 1.8 V to 5.5 V |
| Max Frequency | 64 MHz | 64 MHz | 64 MHz | 64 MHz | 64 MHz | 64 MHz | 64 MHz |
| Temperature Grade | -40C to +125C (E) | -40C to +125C (E) | -40C to +85C (I) | -40C to +85C (I) | -40C to +125C (E) | -40C to +85C (I) | -40C to +85C (I) |
Key Differentiators
- Wider operating voltage than PIC18F27K42 (vs PIC18F27K42-E/SO)
- Latest K42 peripherals vs K40 (vs PIC18LF27K40-E/SO)
- Industrial -40C to +125C range vs I-grade (vs PIC18LF27K42-I/SO)
- Surface-mount SOIC vs hand-soldering SSOP (vs PIC18LF27K42-I/SS)
Design Notes
Place a 100 nF decoupling capacitor as close as possible to each VDD pin (19 and 20), plus a bulk 1 uF to 10 uF tantalum or ceramic on the VDD rail. The PIC18LF27K42-E/SO XLP IDLE mode draws less than 1 uA with PMD bits cleared, but if you leave unused peripherals enabled the quiescent current can rise 10x. Use the PMD register to gate UART, ADC, and PWM modules during sleep, and configure unused I/O as outputs driving low rather than inputs to avoid floating-pin leakage.
At 64 MHz with all peripherals active and I/O toggling, the 28-SOIC package dissipates approximately 60 mW, keeping junction rise well under 5 C above ambient for typical 4-layer boards. For high-I/O LED-driving applications where multiple I/O pins source 20 mA each, total pin power can approach 400 mW - in that case, use a 2 oz copper outer layer or stitch thermal vias under the exposed paddle region of the chip's land pattern, even though the SOIC package does not have a true EPAD.
PPS peripheral pin select remapping is unlocked only after writing PPSLOCK = 0x55 and PPSLOCK = 0xAA in sequence - omit either byte and the register write silently fails. The ICD pins RB6/RB7 are fixed and cannot be remapped, so reserve them for ICSPCLK and ICSPDAT. When migrating from PIC18F to PIC18LF, double-check that VDD never drops below 1.8V during reset brownout; configure BOR at the LF-minimum level, not the F-minimum, or the MCU will fail to start.
Route the 28-SOIC SOIC crystal traces (if using an external crystal instead of HFINTOSC) as short and symmetric as possible, with a ground guard on both sides. Keep ADC analog traces RA0-RA7 separated from digital PWM signals by at least one grounded trace to avoid crosstalk into the 12-bit ADC2 result. Place the ICSP connector (RB6/RB7/VDD/VSS) on the board edge for easy in-circuit debug access during firmware bring-up.
Compliance Information
RoHS and REACH compliant per Microchip product page; not AEC-Q100 qualified - choose PIC18F27K42-E/SO automotive variant for AEC-Q100 needs. Halogen-free per Microchip Material Declaration.
