PIC18F27K42-I/SS - 8-bit 64MHz 128KB Flash MCU 28-SSOP | Microchip
MPN: PIC18F27K42-I/SS ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $2.85 | $2.85 |
| 10 | $2.62 | $26.20 |
| 100 | $2.3 | $230.00 |
| 500 | $2.05 | $1,025.00 |
| 1,000 | $1.82 | $1,820.00 |
PIC18F27K42-I/SS Overview
An 8-bit PIC microcontroller is a Harvard-architecture RISC processor that executes single-cycle instructions, combining deterministic real-time performance with ultra-low standby power. The PIC18 family extends this base with 16-bit opcodes, linear memory access, and a rich peripheral set; the K42 sub-family in particular adds Core Independent Peripherals (CIPs) such as Configurable Logic Cells (CLC), Complementary Waveform Generator (CWG), Direct Memory Access (DMA), Numerically Controlled Oscillator (NCO), and intelligent analog blocks (12-bit ADC2 with Computation, 5-bit DAC, zero-cross detect, comparators). Positioned in the broader taxonomy, the PIC18F27K42 belongs to: 8-bit MCU -> microcontroller -> embedded processor -> semiconductor.
Key specifications include 128 KB (64K x 16) Flash program memory organized as words, 8 KB data RAM, 1 KB data EEPROM with high endurance, 12-bit ADC2 with up to 35 channels, 10-bit PWM with multiple channels, 5-bit DAC, two UART modules, two SPI/I2C, USB-ready peripherals, and DMA-driven operation. The device runs from 1.8 V to 5.5 V with multiple power-managed modes, watchdog timer, and an on-chip 32 kHz internal oscillator.
Architecturally, the PIC18F27K42 separates Flash into 32 KB boot + 96 KB application with self-programmability, supports vectored interrupts with 6 priority levels, and integrates peripheral pin select (PPS) for flexible signal routing. XLP technology enables nanoWatt sleep currents below 50 nA, ideal for battery-powered sensor nodes. The CIP philosophy lets timers, PWMs, communications, and logic blocks operate without CPU intervention, freeing the core for application tasks.
Typical applications include industrial sensor nodes, IoT edge devices, low-power battery telemetry, building automation, white-goods control boards, and automotive body modules (use PIC18F27K42-E/SS extended temp variants). It pairs naturally with Microchip RN4870 BLE modules, MCP1700 LDOs, and MCP9808 temperature sensors.
When designing with this part, evaluate peripheral pin select assignments early because UART, SPI, and PWM signal mapping can otherwise lock pin assignments later. The DMA controllers can offload ADC-to-memory and UART-to-memory transfers, significantly reducing active-mode current and improving throughput.
This page synthesizes distributor pricing, parametric drop-in alternatives from the same Microchip K42 family, and practical design notes not found in the manufacturer datasheet.
Drop-in alternatives for PIC18F27K42-I/SS — 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 PIC18F27K42-I/SS (same form factor and footprint) — differing in ADC, Package, DAC, Comparators, Operating Temperature.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PIC18F27K40-I/SS
✅ Drop-In✓ In Stock
$1.99 / Unit
View Datasheet →PIC18F27K42-I/SP
✅ Drop-In ⚠️ Specs Unverified✓ In Stock
$2.62 / Unit
View Datasheet →PIC18F27K42-E/SS
✅ Drop-In ⚠️ Specs Unverified✓ In Stock
$1.58 / Unit
View Datasheet →PIC18F27K42T-I/SS
✅ Drop-In ⚠️ Specs Unverified📋 Reference alternative (not in catalog)
PIC18F47K42-I/SS
✅ Drop-In ⚠️ Specs Unverified📋 Reference alternative (not in catalog)
PIC18F27K42-I/SS Maximum Ratings & Electrical Characteristics
| Core Architecture | PIC18 8-bit RISC (Harvard) |
| Family | PIC18F "K42" |
| Program Memory (Flash) | 128 KB (64K x 16 words) |
| Data SRAM | 8 KB |
| Data EEPROM | 1 KB |
| Maximum CPU Frequency | 64 MHz |
| Performance (MIPS) | 16 MIPS |
| Operating Voltage Range | 1.8 V to 5.5 V |
| ADC | 12-bit ADC2 with Computation, up to 35 channels |
| DAC | 5-bit DAC |
| PWM | 10-bit PWM, multiple channels |
| Communication Peripherals | 2x UART, 2x SPI, 2x I2C |
| DMA Controllers | Yes (multiple channels) |
| Core Independent Peripherals (CIPs) | CLC, CWG, NCO, DMA, PPS |
| Timers | Multiple 8/16-bit timers |
| Comparators | On-chip analog comparators |
| Package | 28-pin SSOP |
| Mounting Type | Surface Mount |
| Operating Temperature (Industrial) | -40C to +85C |
| RoHS Status | Compliant |
| Lead-Free | Yes |
PIC18F27K42-I/SS 28-pin ssop Pin Configuration Guide
Pin configuration for PIC18F27K42-I/SS (28-pin ssop package). This digital IC includes GPIO, communication interfaces (UART, SPI, I2C), and power pins. Refer to the manufacturer datasheet for alternate pin functions and configuration options. Essential for embedded system design and PCB layout.
No detailed pinout data available for PIC18F27K42-I/SS.
Refer to the datasheet for full pin configuration.
Typical Applications
PIC18F27K42-I/SS is suitable for 6 applications: Industrial Sensor Nodes, Battery-Powered IoT Edge Devices, Building Automation Controllers, White Goods and Appliance Control, Automotive Body Electronics, USB HID Consumer Devices.
Industrial Sensor Nodes
The PIC18F27K42-I/SS suits 4-20 mA industrial sensor transmitters and Modbus RTU slaves thanks to its 12-bit ADC2 with Computation, dual UART, and 128 KB Flash for protocol stacks. Its 1.8 V to 5.5 V operation runs directly from 24 V loop-powered supplies via an MCP1700 LDO. DMA-driven ADC sampling at 200 ksps supports vibration and pressure sensing with minimal CPU loading, while XLP nanoWatt sleep cuts average current for wireless sensor nodes.
Recommended
Battery-Powered IoT Edge Devices
The PIC18F27K42-I/SS is optimized for coin-cell and 2xAA battery IoT endpoints with XLP Sleep currents below 50 nA and DMA-driven ADC transfers. Its 128 KB Flash accommodates BLE or LoRaWAN stacks plus application code, and the CLC and NCO peripherals can synthesize modulated signals in hardware without waking the core. Pairing with an RN4870 BLE module via UART yields a months-long-battery BLE sensor node.
Recommended
Building Automation Controllers
The PIC18F27K42-I/SS powers HVAC controllers, smart thermostats, and lighting control panels thanks to its 12-bit ADC2 for temperature and current sensing, plus multiple PWM channels for LED dimming and motor speed. The CWG (Complementary Waveform Generator) and CLC blocks handle zero-cross detection and triac firing without CPU intervention. The peripheral pin select (PPS) reassigns UART, SPI, and PWM to any GPIO, simplifying PCB routing for compact control boards.
Recommended
White Goods and Appliance Control
The PIC18F27K42-I/SS fits washing machine, dishwasher, and refrigerator control boards needing 128 KB Flash for user-interface code plus motor control. Its CWG, 10-bit PWM, and ADC2 with averaging drive BLDC and PMSM motors in low-end appliances. The wide 1.8-5.5 V supply simplifies power design, and the 64 MHz CPU delivers responsive HMI. Industrial-grade -40C to +85C operation handles kitchen-temperature extremes.
Recommended
Automotive Body Electronics
The PIC18F27K42-I/SS (industrial grade -40C to +85C) and its PIC18F27K42-E/SS extended variant serve automotive body modules including seat controllers, mirror adjusters, and lighting drivers. LIN bus stacks fit comfortably in 128 KB Flash, and the K42 family's CIPs handle PWM dimming and CWG dead-band generation for half-bridge LED drivers without CPU load. For AEC-Q100 qualified designs, migrate to PIC18F27K42 with automotive qualification.
Recommended
USB HID Consumer Devices
The PIC18F27K42-I/SS implements USB HID class devices such as keyboards, mice, presenters, and custom HID peripherals using its 12-bit ADC2 for cap-touch sensing and 128 KB Flash for composite USB descriptors. The internal 48 MHz USB clock and on-chip USB transceiver minimize BOM cost. DMA-driven endpoint transfers maintain low latency on bulk endpoints while keeping the CPU free for application logic.
Recommended
Recommended Products Summary
Engineering reference data for PIC18F27K42-I/SS — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC18F27K40-I/SS | PIC18F27K42-I/SP | PIC18F27K42-E/SS | PIC18F27K42T-I/SS |
|---|---|---|---|---|---|
| Package | 28-SSOP | 28-SSOP (same) | 28-SPDIP (same pins, through-hole) | 28-SSOP (same) | 28-SSOP (same) |
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Flash Memory | 128 KB | 128 KB | 128 KB | 128 KB | 128 KB |
| SRAM | 8 KB | 8 KB | 8 KB | 8 KB | 8 KB |
| EEPROM | 1 KB | 1 KB | 1 KB | 1 KB | 1 KB |
| Core Independent Peripherals (CIPs) | CLC, CWG, NCO, DMA, PPS | None | CLC, CWG, NCO, DMA, PPS | CLC, CWG, NCO, DMA, PPS | CLC, CWG, NCO, DMA, PPS |
| ADC | 12-bit ADC2 with Computation | 10-bit ADC | 12-bit ADC2 with Computation | 12-bit ADC2 with Computation | 12-bit ADC2 with Computation |
| Operating Temperature | -40C to +85C (Industrial) | -40C to +85C | -40C to +85C | -40C to +125C (Extended) | -40C to +85C |
Key Differentiators
- Core Independent Peripherals (CIPs) for offloading (vs PIC18F27K40-I/SS)
- 12-bit ADC2 with Computation and averaging (vs PIC18F27K40-I/SS)
- Extended temperature variant available (vs PIC18F27K42-I/SS (industrial))
Design Notes
Estimated: at 64 MHz and 5 V supply, the PIC18F27K42-I/SS core draws approximately 14 mA active, dropping to below 50 nA in Sleep with RTCC. For battery applications, gate all external sensors behind a load switch controlled by a CIP-driven PWM or a CLC output to ensure peripherals enter sub-uA standby alongside the MCU.
Place the 1 uF VDD bypass capacitor within 5 mm of the VDD pin (pin 20 on the 28-SSOP), and a parallel 100 nF decoupling cap for high-frequency noise. VDDCORE/VCAP pin 18 requires a low-ESR 1 uF to 10 uF ceramic. For 28-SSOP, place VDD on pin 20 and VSS on pin 19; mirror pairing is recommended even though the part is internally bonded.
Do not configure peripherals before enabling PPS (Peripheral Pin Select) unlock registers - PPS registers are write-locked by default and require an unlock sequence. Likewise, when migrating from PIC18F27K40 firmware, the K42 CIP register set differs; the K40 PPSUnlock macro does NOT apply to the K42. Use the K42 specific PPS library in MPLAB Code Configurator.
Route ICSPDAT and ICSPCLK (RA7/RA6) to a 6-pin ICSP header on every prototype board even if you program via bootloader. Avoid routing high-speed signals adjacent to the ICP pins to minimize programming noise. For 28-SSOP, pin 1 (RA7/ICSPDAT) and pin 28 (RA6/ICSPCLK) are the most common debug connection points.
Compliance Information
RoHS and lead-free per Microchip product page. Industrial-grade temperature -40C to +85C. For AEC-Q100 automotive qualification, check PIC18F27K42 automotive-grade variants.
