PIC18F27K42-I/SP - 8-bit 64MHz MCU 128KB Flash 28-SPDIP | Microchip
MPN: PIC18F27K42-I/SP ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $4.1 | $4.10 |
| 10 | $3.69 | $36.90 |
| 100 | $3.28 | $328.00 |
| 500 | $2.95 | $1,475.00 |
| 1,000 | $2.62 | $2,620.00 |
PIC18F27K42-I/SP Overview
An 8-bit microcontroller (MCU) is a programmable single-chip computer that processes data 8 bits at a time and integrates CPU, RAM, non-volatile program memory (Flash/ROM), EEPROM, digital I/O, timers, communication peripherals and often analog blocks. Within the broader taxonomy, the PIC18F27K42 belongs to: microcontroller -> 8-bit MCU -> PIC18 family -> PIC18F2XK42 sub-family -> embedded controller. MCUs form the lowest tier of programmable logic above discrete logic, and are the workhorse of low-cost, low-power embedded control in appliances, sensors and motor nodes.
Key features of this part include: the ADC2 with Computation engine that performs averaging, oversampling and threshold comparison in hardware (offloading the CPU), a charge-pump-assisted low-voltage ADC that remains accurate at VDD as low as 2.3 V, the Peripheral Pin Select (PPS) remapping matrix, and Microchip's eXtreme Low Power (XLP) technology with deep-sleep currents in the nanoamp range and multiple IDLE/DOZE/PMD power modes. A DMA-like unified data signal router, a 32-bit CRC scanner, and an integrated temperature indicator round out the on-chip intelligence.
Architecturally, this device uses a 16-bit instruction word with 8-bit data path, Harvard cache, single-cycle hardware multiplier, vectored interrupts with hardware context save, and a deterministic interrupt latency. The Instruction Set Architecture (ISA) is the standard PIC18 instruction set with F2-generation extensions, supported by MPLAB X IDE, XC8 compiler and Microchip's Code Configurator graphical pin/peripheral setup.
Typical applications include: home-automation capacitive-touch user interfaces, IoT sensor nodes, low-power battery-powered instruments, industrial control with multiple serial interfaces, and small appliance motor control. The wide VDD range and on-chip 12-bit ADC make it suitable for sensor-rich applications where BOM cost must stay low.
When designing with this MCU, budget adequate VDD decoupling (100 nF + 1 uF bulk) within 5 mm of the supply pins, leave the MCLR pin accessible (or driven by an RC) for in-circuit serial programming (ICSP), and choose the SPDIP package only when through-hole assembly or socketed prototyping is needed; for high-volume SMT designs migrate to PIC18F27K42-I/SO (SOIC-28) or PIC18F27K42-I/ML (QFN-28).
This page consolidates distributor pricing, datasheet pinout, drop-in alternatives, and design notes not found in the manufacturer datasheet alone.
Drop-in alternatives for PIC18F27K42-I/SP — 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/SP (same form factor and footprint) — differing in Core, ADC, Package, DAC, Mounting Type.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PIC18F27K42-E/SP
✅ Drop-In✓ In Stock
$2.21 / Unit
View Datasheet →PIC18F26K42-I/SP
✅ Drop-In📋 Reference alternative (not in catalog)
PIC18F27K40-I/SP
✅ Drop-In📋 Reference alternative (not in catalog)
PIC18F27K42-I/SP Maximum Ratings & Electrical Characteristics
| Core | PIC18 8-bit enhanced mid-range |
| Program Memory (Flash) | 128 KB |
| Data SRAM | 8 KB |
| Data EEPROM | 1 KB |
| Maximum CPU Speed | 64 MHz |
| Operating Voltage (VDD) | 2.3 V to 5.5 V |
| Package | 28-pin SPDIP (Skinny Plastic DIP) |
| I/O Pins | 25 |
| ADC | 12-bit ADC2 with Computation, up to 35 external channels |
| DAC | 5-bit, 2 channels |
| Comparators | 2 with 9 selectable inputs each |
| Timers | 8-/16-bit, multiple (PWM, SCCP, ECCP) |
| Communication | 2x I2C, 2x SPI, 3x UART (with PPS remap) |
| Peripheral Pin Select (PPS) | Yes (24 channels) |
| Hardware CVD (Capacitive Touch) | Yes |
| eXtreme Low Power (XLP) | Yes - nanoamp sleep current |
| Operating Temperature Range | -40C to +85C (Industrial; -I suffix) |
| ICSP / Debug | In-Circuit Serial Programming, ICD support |
| RoHS Status | Compliant |
PIC18F27K42-I/SP Pin Configuration
| Pin 1 | RA0/AN0/PWM1 — PORTA bit 0 / ADC input / PWM output 1 |
| Pin 2 | RA1/AN1/PWM2 — PORTA bit 1 / ADC input / PWM output 2 |
| Pin 3 | RA2/AN2 — PORTA bit 2 / ADC input |
| Pin 4 | RA3/AN3/VREF+ — PORTA bit 3 / ADC input / positive voltage reference |
| Pin 5 | RA4/AN4/CCP1 — PORTA bit 4 / ADC input / Capture-Compare-PWM 1 |
| Pin 6 | RA5/AN5/DAC1OUT — PORTA bit 5 / ADC input / DAC1 output |
| Pin 7 | RA6/AN6/DAC2OUT — PORTA bit 6 / ADC input / DAC2 output |
| Pin 8 | RA7 — PORTA bit 7 (digital only) |
| Pin 9 | RE3/MCLRn — PORTE bit 3 / Master Clear (reset, active-low) |
| Pin 10 | RB0/AN12 — PORTB bit 0 / ADC input |
| Pin 11 | RB1/AN10 — PORTB bit 1 / ADC input |
| Pin 12 | RB2/AN8 — PORTB bit 2 / ADC input |
| Pin 13 | RB3/AN9 — PORTB bit 3 / ADC input |
| Pin 14 | RB4/AN11 — PORTB bit 4 / ADC input |
| Pin 15 | RB5/AN13 — PORTB bit 5 / ADC input |
| Pin 16 | RB6/ICSPCLK — PORTB bit 6 / ICSP clock |
| Pin 17 | RB7/ICSPDAT — PORTB bit 7 / ICSP data |
| Pin 18 | VDD — Positive supply voltage (2.3 V to 5.5 V) |
| Pin 19 | VSS — Ground reference |
| Pin 20 | RC0 — PORTC bit 0 |
| Pin 21 | RC1 — PORTC bit 1 |
| Pin 22 | RC2/AN14 — PORTC bit 2 / ADC input |
| Pin 23 | RC3/AN15 — PORTC bit 3 / ADC input |
| Pin 24 | RC4 — PORTC bit 4 |
| Pin 25 | RC5 — PORTC bit 5 |
| Pin 26 | RC6 — PORTC bit 6 |
| Pin 27 | RC7 — PORTC bit 7 |
| Pin 28 | NC — Not connected (no internal bond to pin) |
Typical Applications
PIC18F27K42-I/SP is suitable for 6 applications: Home-Automation Capacitive-Touch UI, Industrial Sensor Node / 4-20 mA Transmitter, Low-Power Battery-Powered IoT Sensor, Small Appliance Motor Control, Automotive Body and Interior Module, Smart Energy Meter / Data Logger.
Home-Automation Capacitive-Touch UI
The PIC18F27K42-I/SP is purpose-built for capacitive-touch user interfaces thanks to its hardware CVD (Capacitive Voltage Divider) module that automates touch sampling and shielding, plus the ADC2 with Computation engine that handles averaging and oversampling in hardware. With 128 KB Flash and 8 KB SRAM, the device can host a complete mTouch or custom touch algorithm, a graphical or LED status display driver, and a wireless interface to a hub. The 25 I/O pins are ample for 12-16 touch buttons plus RGB indicators, while eXtreme Low Power modes keep sleep current in the microamp range so battery-powered remotes can run for years.
Recommended
Industrial Sensor Node / 4-20 mA Transmitter
For industrial 4-20 mA loop-powered transmitters, the PIC18F27K42-I/SP's 12-bit ADC2 with charge-pump-assisted low-voltage operation maintains accuracy at VDD as low as 2.3 V, critical for loop compliance at the low end of the 4 mA bias current. The on-chip 5-bit DAC and two comparators support HART-style modulation or simple analog output filtering, while the 128 KB Flash fits MODBUS, DLP-IDs (Device Labeling Protocol) stacks or device-specific calibration. Hardware math acceleration in the 16-bit MIPS core delivers deterministic cycle counts needed for IEC 61508-style SIL-1 designs.
Recommended
Low-Power Battery-Powered IoT Sensor
Battery-powered IoT sensor nodes rely on the PIC18F27K42-I/SP's eXtreme Low Power (XLP) technology, with deep-sleep currents measured in nanoamps and multiple IDLE/DOZE/PMD power modes. The PIC18F27K42-I/SP can wake from sleep via RTC, IOC pin change, ADC threshold or comparator, then transmit via UART-connected radio and return to sleep - duty cycles below 1% are routine. The 128 KB Flash supports BLE/Zigbee/LoRa protocol stacks, while the 8 KB SRAM and 1 KB EEPROM handle sensor buffering and non-volatile configuration storage without external memory.
Recommended
Small Appliance Motor Control
Small brushless-DC or stepper-motor controllers in appliances benefit from the PIC18F27K42-I/SP's 16-bit PWM with complementary outputs, 24-channel Peripheral Pin Select, and 64 MHz CPU that delivers precise commutation timing. The 12-bit ADC reads back-current via integrated op-amps or external sense resistors, while the UART interfaces host a user-facing display or BLE module. The -I/SP industrial temperature range and SPDIP package simplify through-hole manufacturing for ceiling fans, washing-machine pumps, or HVAC damper actuators.
Recommended
Automotive Body and Interior Module
While the -I/SP variant is industrial-temperature rated (not AEC-Q100), the PIC18F27K42 silicon is widely used in non-safety automotive interior modules such as HVAC control panels, lighting drivers and seat controllers. The 12-bit ADC reads temperature and position sensors, the PWM outputs drive LED matrices, and LIN/UART interfaces connect to the body network. For AEC-Q100 needs Microchip offers the PIC18F27K42 automotive equivalent; this -I/SP version suits aftermarket and prototyping work where industrial temperature is sufficient.
Recommended
Smart Energy Meter / Data Logger
Single-phase energy meters and data loggers leverage the PIC18F27K42-I/SP's 12-bit ADC2 for voltage and current sensing, the 1 KB EEPROM for tamper-resistant energy counters and tariff tables, and 128 KB Flash for DLMS/COSEM or Open Smart Energy Gateway stacks. The hardware CRC scanner detects flash corruption, and the eXtreme Low Power modes enable battery-backed RTC operation during power outages. Multiple UARTs support optical port (IEC 62056-21) and M-Bus communication, while the SPDIP package is well suited to utility-meter production lines still using through-hole assembly.
Recommended
Recommended Products Summary
Engineering reference data for PIC18F27K42-I/SP — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC18F27K42-E/SP | PIC18F26K42-I/SP | PIC18F27K40-I/SP |
|---|---|---|---|---|
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Package | SPDIP-28 | SPDIP-28 - same | SPDIP-28 - same | SPDIP-28 - same |
| Flash Memory | 128 KB | 128 KB | 64 KB | 128 KB |
| SRAM | 8 KB | 8 KB | 8 KB | 8 KB |
| EEPROM | 1 KB | 1 KB | 1 KB | 1 KB |
| Maximum CPU Frequency | 64 MHz | 64 MHz | 64 MHz | 64 MHz |
| Operating Voltage | 2.3 V to 5.5 V | 2.3 V to 5.5 V | 2.3 V to 5.5 V | 2.3 V to 5.5 V |
| Temperature Range | -40C to +85C (Industrial) | -40C to +125C (Extended) | -40C to +85C (Industrial) | -40C to +85C (Industrial) |
| ADC Resolution / Channels | 12-bit / up to 35 channels (ADC2 with Computation) | 12-bit / up to 35 channels (ADC2) | 12-bit / up to 35 channels (ADC2) | 12-bit / up to 35 channels (legacy ADC, no Computation) |
| Hardware Capacitive Touch (CVD) | Yes | Yes | Yes | No |
Key Differentiators
- ADC2 with hardware Computation (averaging, oversampling, threshold compare) offloads the CPU and improves signal-to-noise on slow sensors (vs PIC18F27K40-I/SP)
- 128 KB Flash fits more protocol stacks and bootloaders in a single chip (vs PIC18F26K42-I/SP)
- On-chip CVD (Capacitive Voltage Divider) eliminates external touch controller cost (vs PIC18F26K22-I/SP)
Design Notes
Place a 100 nF ceramic decoupling capacitor within 5 mm of the VDD pin (pin 18) and a 1 uF to 10 uF bulk capacitor adjacent to the IC. The PIC18F27K42-I/SP is sensitive to VDD ripple during ADC2 conversions; use a ferrite bead or pi-filter if the supply also feeds a switching converter. Estimated: at 64 MHz active current is roughly 15 mA per datasheet typical curves, so the 1 uF bulk should sustain VDD during sudden load steps without dropping below 2.3 V.
Reserve a 4.7 kohm pull-up on MCLR (pin 9) and dedicated test points on RB6/ICSPCLK (pin 16) and RB7/ICSPDAT (pin 17) for in-circuit serial programming and ICD debugging. Routing these three signals to a 1x3 header simplifies firmware updates in production and field service. Keep ICSP traces short (under 50 mm) and avoid running them next to high-current switching traces to prevent programming failures.
Do not leave the floating analog pins unconfigured: PIC18F27K42-I/SP analog inputs that are not used should be tied to VSS or set as digital outputs to prevent floating input-induced current. The Peripheral Pin Select (PPS) registers must be unlocked before modification (sequence: write 0x55, write 0xAA, then the IOLOCK bit) - a common source of brown-out code that appears to hang the MCU after reset. The ADC2 charge pump requires at least 1 us settling time after enable before the first conversion.
Estimated: the SPDIP-28 package has a theta_JA of approximately 70 C/W in still air, so 50 mW dissipation yields only a 3.5 C junction temperature rise. Even at 100 mA active current (rare on this MCU) the thermal rise is acceptable for industrial -40C to +85C environments. The eXtreme Low Power sleep mode brings total current to under 1 uA typical - in battery designs, total system energy is dominated by sleep current, not active power.
Compliance Information
RoHS compliant per Microchip product page; industrial temperature -40C to +85C only - not AEC-Q100 qualified. Choose the -I/SP AEC variant for automotive.
