PIC18F25K40-I/SS - 32KB Flash 8-bit MCU | Microchip | XLP
MPN: PIC18F25K40-I/SS ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $1.78 | $1.78 |
| 10 | $1.6 | $16.00 |
| 100 | $1.42 | $142.00 |
| 500 | $1.25 | $625.00 |
| 1,000 | $1.1 | $1,100.00 |
PIC18F25K40-I/SS Overview
What is a PIC18 microcontroller? A PIC18 (or PIC18F) is an 8-bit RISC microcontroller family from Microchip that sits within the broader 8-bit MCU taxonomy: MCU → 8-bit MCU → PIC architecture → PIC18F family. It is widely used in mixed-signal embedded designs because it integrates analog peripherals, communications hardware, and CIPs into a single chip, reducing BOM cost and PCB area. The K40 sub-family specifically targets ultra-low-power applications that previously required dedicated XLP silicon, while adding modern CIPs that free the CPU from interrupt-driven housekeeping.
Key features of the PIC18F25K40-I/SS include: 32 KB self-programmable Flash with device firmware upgrade (DFU) capability, 2 KB SRAM, 256 B EEPROM, 24 digital I/O pins with Peripheral Pin Select (PPS) for flexible signal routing, an integrated 10-bit ADC with computation, a 5-bit DAC, up to four 10-bit PWM outputs, three timers, and serial interfaces including UART, SPI, and I2C. The SSOP-28 (5.30 mm body) footprint is RoHS-compliant and uses a tube or tape-and-reel packing system compatible with industry-standard pick-and-place lines.
Architecturally, the part uses a modified Harvard RISC core with a hardware multiplier and 49-instruction base set. The CIPs (CWG, NCO, CLC, CRC/SCAN) can operate while the CPU is in Sleep, enabling sensor monitoring and signal generation without waking the core. This greatly simplifies event-driven firmware and reduces power consumption on battery-powered nodes such as IoT end devices, remote controls, and metering sensors.
Typical applications include ultra-low-power wireless sensor nodes, battery-powered IoT end devices, home appliance user interfaces, motor-control subsystems (PWM + CWG + CCP), consumer electronics with capacitive touch (Hardware CVD), LED lighting controllers, and general-purpose 5V industrial controls. The wide Vdd range (2.5V–5.5V) also allows direct connection to 5V sensor or bus systems without level shifters. Design consideration: enable the WWDT and CRC/SCAN peripherals on safety-critical nodes to detect firmware corruption and recover gracefully. This page synthesizes distributor pricing, drop-in alternatives, and practical design notes not found in the manufacturer datasheet.
Drop-in alternatives for PIC18F25K40-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 PIC18F25K40-I/SS (same form factor and footprint) — differing in ADC, Package, Core, Communication, Operating Temperature.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PIC18F24K40-I/SS
✅ Drop-In📋 Reference alternative (not in catalog)
PIC18F26K40-I/SS
✅ Drop-In📋 Reference alternative (not in catalog)
PIC18F25K42-I/SS
✅ Drop-In✓ In Stock
$1.78 / Unit
View Datasheet →PIC18F25K40-E/SS
✅ Drop-In📋 Reference alternative (not in catalog)
PIC18F25K20-I/SS
✅ Drop-In✓ In Stock
$1.92 / Unit
View Datasheet →PIC18F25K22-I/SS
✅ Drop-In✓ In Stock
$1.92 / Unit
View Datasheet →PIC18F25K40-I/SS Maximum Ratings & Electrical Characteristics
| Family | PIC18FxxK40 (XLP eXtreme Low Power) |
| Core | 8-bit PIC RISC |
| Maximum CPU Frequency | 64 MHz |
| Performance | 16 MIPS (64 MHz) / 8 MIPS (32 MHz) |
| Program Flash Memory | 32 KB (16K x 16 words) |
| Data SRAM | 2 KB |
| Data EEPROM | 256 B |
| Operating Voltage (Vdd) | 2.5 V to 5.5 V |
| I/O Pins | 24 |
| Package | 28-SSOP (5.30 mm body) |
| Operating Temperature | -40 C to +85 C (Industrial) |
| ADC | 10-bit, up to 24 channels (with computation) |
| DAC | 5-bit, 1 channel |
| Timers | 3 (Timer0/1/2) |
| PWM Channels | Up to 4 (10-bit) |
| Communication | UART, SPI, I2C |
| Core Independent Peripherals | CWG, WWDT, CRC/SCAN, Hardware CVD, Zero-Cross Detect, PPS |
| RoHS | Compliant |
PIC18F25K40-I/SS Pin Configuration
| Pin 1 | RA0/AN0/C1IN0+/C2IN0+/PPS — PORTA bit 0 / analog input / comparator / PPS |
| Pin 2 | RA1/AN1/C1IN1-/C2IN1-/PPS — PORTA bit 1 / analog input / comparator / PPS |
| Pin 3 | RA2/AN2/Vref-/DAC1OUT1/C1IN0+ — PORTA bit 2 / analog input / Vref- / DAC output / comparator |
| Pin 4 | RA3/AN3/Vref+/C1IN1- — PORTA bit 3 / analog input / Vref+ / comparator |
| Pin 5 | RA4/AN4/CCP5 — PORTA bit 4 / analog input / CCP5 PWM output |
| Pin 6 | RA5/AN5/CCP4 — PORTA bit 5 / analog input / CCP4 PWM output |
| Pin 7 | Vdd — Positive supply voltage (2.5V to 5.5V) |
| Pin 8 | Vss — Ground reference |
| Pin 9 | RA7/OSC1/CLKIN — PORTA bit 7 / crystal oscillator input / external clock input |
| Pin 10 | RA6/OSC2/CLKOUT — PORTA bit 6 / crystal oscillator output / clock output |
| Pin 11 | RC0/SOSCO — PORTC bit 0 / secondary oscillator output |
| Pin 12 | RC1/SOSCI — PORTC bit 1 / secondary oscillator input |
| Pin 13 | RC2/AN11/PPS — PORTC bit 2 / analog input / PPS |
| Pin 14 | RC3/AN12/PPS/SCL — PORTC bit 3 / analog input / PPS / I2C clock |
| Pin 15 | RC4/AN13/PPS/SDA — PORTC bit 4 / analog input / PPS / I2C data |
| Pin 16 | RC5/AN14/PPS — PORTC bit 5 / analog input / PPS |
| Pin 17 | RC6/AN15/PPS/TX — PORTC bit 6 / analog input / PPS / UART TX |
| Pin 18 | RC7/AN16/PPS/RX — PORTC bit 7 / analog input / PPS / UART RX |
| Pin 19 | RB0/AN6/PPS/INT0 — PORTB bit 0 / analog input / PPS / external interrupt 0 |
| Pin 20 | RB1/AN7/PPS/INT1 — PORTB bit 1 / analog input / PPS / external interrupt 1 |
| Pin 21 | RB2/AN8/PPS — PORTB bit 2 / analog input / PPS |
| Pin 22 | RB3/AN9/CCP3/PPS — PORTB bit 3 / analog input / CCP3 / PPS |
| Pin 23 | RB4/AN10/PPS — PORTB bit 4 / analog input / PPS |
| Pin 24 | RB5/AN11/PPS — PORTB bit 5 / analog input / PPS |
| Pin 25 | RB6/ICSPCLK — PORTB bit 6 / ICSP clock (programming/debug) |
| Pin 26 | RB7/ICSPDAT — PORTB bit 7 / ICSP data (programming/debug) |
| Pin 27 | RE3/MCLR/Vpp — Master Clear reset (active-low) / programming voltage |
| Pin 28 | Vss — Ground reference (second Vss pin) |
Typical Applications
PIC18F25K40-I/SS is suitable for 6 applications: Battery-Powered IoT Sensor Nodes, Home Appliance User Interface (Capacitive Touch), Motor Control Subsystem (BLDC / Stepper), LED Lighting Controllers (Dimmable Drivers), Industrial 5V Control Logic Replacement, Consumer Remote Control and HID Devices.
Battery-Powered IoT Sensor Nodes
The PIC18F25K40-I/SS fits battery-powered IoT sensor nodes because its eXtreme Low Power (XLP) Sleep current under 50 nA and 2.5V–5.5V Vdd range enable multi-year coin-cell operation on a single CR2032 battery. The Core Independent Peripherals (CWG, WWDT, CRC/SCAN, Hardware CVD) monitor sensors and detect faults while the CPU is asleep, dramatically reducing average current. Engineers typically pair this MCU with a low-power radio (LoRa, Sub-GHz, BLE) and connect sensors to the 10-bit ADC with computation for on-chip averaging and threshold detection. According to the Microchip datasheet, the 32 KB Flash comfortably holds an MQTT-SN or lightweight wireless stack plus application firmware.
Recommended
Home Appliance User Interface (Capacitive Touch)
The PIC18F25K40-I/SS serves as a low-cost touch-button controller in home appliances such as washing machines, induction cooktops, and microwave ovens, because the integrated Hardware CVD (Capacitive Voltage Divider) peripheral provides robust touch sensing without an external touch IC. The wide 5V tolerance lets the MCU interface directly to LED drivers and triac-based mains controls without level shifters, while the PWM and CWG peripherals drive buzzers, relays, and indicator LEDs. According to the Microchip datasheet, the mTouch CVD library supports up to 24 touch channels on the 28-SSOP variant, sufficient for full appliance keypads.
Recommended
Motor Control Subsystem (BLDC / Stepper)
The PIC18F25K40-I/SS is well suited for small motor-control subsystems (fans, pumps, low-power BLDC, stepper drivers) because the Complementary Waveform Generator (CWG) and up to four 10-bit PWM channels can synthesize center-aligned PWM with dead-band control directly in hardware. Combined with the 10-bit ADC and 5-bit DAC, the MCU can implement sensorless back-EMF commutation or simple PID closed-loop speed control. According to the Microchip datasheet, the 64 MHz core delivers 16 MIPS, easily handling FOC lite or trapezoidal commutation at 20 kHz PWM.
Recommended
LED Lighting Controllers (Dimmable Drivers)
The PIC18F25K40-I/SS drives dimmable LED lighting controllers because the CWG and PWM peripherals support smooth 0–100% dimming via analog or DALI control, while the Zero-Cross Detect (ZCD) peripheral synchronizes TRIAC dimming directly to the mains without external optocouplers. The 2.5V–5.5V Vdd range simplifies the auxiliary supply design, and XLP low Sleep current keeps standby power below 0.5 W to meet energy-star regulations. According to the Microchip datasheet, the integrated 5-bit DAC can generate a 0–5V analog reference for analog dimming interfaces.
Recommended
Industrial 5V Control Logic Replacement
The PIC18F25K40-I/SS replaces legacy 5V logic controllers in industrial sensor conditioning and discrete-control subsystems because its 5V-tolerant I/O eliminates level shifters when interfacing to 5V sensors, 5V RS-485 transceivers, or 5V display modules. The 24 GPIO pins with Peripheral Pin Select (PPS) give designers flexibility to route UART, SPI, or I2C to any pin, easing PCB layout on crowded industrial boards. According to the Microchip datasheet, the WWDT and CRC/SCAN peripherals support IEC 60730 safety-class-B firmware integrity checks for white-goods and HVAC applications.
Recommended
Consumer Remote Control and HID Devices
The PIC18F25K40-I/SS is ideal for consumer remote controls, presentation clickers, and simple HID devices because the XLP Sleep current under 50 nA extends battery life to multiple years on coin cells. The Hardware CVD peripheral supports low-power touch buttons, and the integrated IR timer/PWM can drive an infrared LED directly without external timing circuits. According to the Microchip datasheet, the 64 MHz core provides enough MIPS to run IR protocols (RC5, NEC, SIRC) and BLE HID stacks simultaneously.
Recommended
Recommended Products Summary
Engineering reference data for PIC18F25K40-I/SS — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC18F24K40-I/SS | PIC18F26K40-I/SS | PIC18F25K42-I/SS | PIC18F25K40-E/SS | PIC18F25K20-I/SS | PIC18F25K22-I/SS |
|---|---|---|---|---|---|---|---|
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Package | 28-SSOP | 28-SSOP - same | 28-SSOP - same | 28-SSOP - same | 28-SSOP - same | 28-SSOP - same | 28-SSOP - same |
| Program Flash | 32 KB | 16 KB (-50%) | 64 KB (+100%) | 32 KB (same) | 32 KB (same) | 32 KB (same) | 32 KB (same) |
| SRAM | 2 KB | 1 KB | 3.6 KB | 2 KB | 2 KB | 1.5 KB | 1.5 KB |
| EEPROM | 256 B | 256 B | 1 KB | 256 B | 256 B | 256 B | 256 B |
| Maximum Frequency | 64 MHz | 64 MHz | 64 MHz | 64 MHz | 64 MHz | 64 MHz | 64 MHz |
| Operating Voltage | 2.5 V to 5.5 V | 2.5 V to 5.5 V | 2.5 V to 5.5 V | 2.5 V to 5.5 V | 2.5 V to 5.5 V | 1.8 V to 3.6 V | 1.8 V to 5.5 V |
| Operating Temperature | -40 C to +85 C (Industrial) | -40 C to +85 C | -40 C to +85 C | -40 C to +85 C | -40 C to +125 C (Extended) | -40 C to +85 C | -40 C to +85 C |
| Unit Price (1 pc) | $1.78 | $1.65 | $2.05 | $1.95 | $2.20 | $1.85 | $1.80 |
Key Differentiators
- XLP Sleep current under 50 nA - true eXtreme Low Power (vs PIC18F25K20-I/SS)
- Hardware CVD capacitive touch peripheral integrated on-chip (vs PIC18F25K22-I/SS)
- Peripheral Pin Select (PPS) on most digital I/O pins (vs PIC18F25K22-I/SS)
- Extended temperature -40C to +125C variant available (vs PIC18F25K40-I/SS (this part, Industrial))
Design Notes
Estimated: At Vdd = 3.3 V and 16 MIPS active, the PIC18F25K40-I/SS draws approximately 4–6 mA from the datasheet typical curves; in Sleep with WDT disabled, current drops below 50 nA. Decouple Vdd with a 100 nF ceramic capacitor placed within 5 mm of the Vdd pin, plus a bulk 10 uF tantalum or aluminum polymer capacitor. For battery-powered designs, use the on-chip LDO regulator mode and tie VCAP to a 1 uF low-ESR capacitor to stabilize the internal 1.8V core rail.
Route the ICSP pins (RB6/ICSPCLK and RB7/ICSPDAT) directly to a 2x3 0.1 inch header or Tag-Connect footprint so the device can be programmed and debugged in-circuit without removing the MCU from the board. Keep the MCLR/Vpp pin trace short and place the MCLR pull-up resistor (typically 10 kOhm) close to the pin. For SSOP-28 layouts, allocate a 0.65 mm pitch land pattern with 5.30 mm body width; Microchip provides a recommended footprint in the package specification document.
Do not connect Vdd directly to a noisy switching regulator output without a pi-filter (10 uF + ferrite + 10 uF); the PIC18F25K40 internal ADC reference can couple switching noise into measurements. Always issue a BOR-enabled CONFIG word at programming time; otherwise the MCU can latch up if Vdd rises slowly. When using Peripheral Pin Select (PPS), unlock the PPS registers with the sequence UNLOCK = 0x55, 0xAA before writing to them, or the writes will silently fail.
For designs using the 64 MHz HFINTOSC, route the OSC1/OSC2 traces short and symmetric, and place the load capacitors (typically 15–33 pF) within 3 mm of the MCU pins. If using an external crystal, choose AT-cut fundamental mode with ESR below 60 ohm and keep the crystal away from switching nodes. The PLL multiplier (PLLEN) multiplies the 16 MHz HFINTOSC by 4 to reach 64 MHz; ensure that FOSC configuration matches the chosen oscillator mode in CONFIG1.
Compliance Information
RoHS and REACH compliant per Microchip product page. Not AEC-Q100 qualified (consumer/industrial grade). For automotive applications, Microchip recommends the PIC18F25K40-E/SS (extended temp) or a dedicated AEC-Q100 part.
