PIC18F25K20-I/SS - 32KB Flash 8-bit MCU, 64MHz XLP | Microchip
MPN: PIC18F25K20-I/SS ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $3.5 | $3.50 |
| 10 | $3.15 | $31.50 |
| 100 | $2.78 | $278.00 |
| 500 | $2.45 | $1,225.00 |
| 1,000 | $2.18 | $2,180.00 |
| 3,000 | $1.92 | $5,760.00 |
PIC18F25K20-I/SS Overview
A microcontroller (MCU) is a single-chip computer containing a CPU, non-volatile program memory, working RAM, and a rich set of on-chip peripherals such as timers, ADC/DAC, communication interfaces (UART, SPI, I2C), and general-purpose I/O. PIC microcontrollers use a RISC-based Harvard architecture with separate program and data buses, allowing simultaneous instruction fetch and operand access, and the 8-bit PIC18 family extends the classic PIC core with 16-bit instructions, linear memory addressing, and a C-optimized instruction set that simplifies firmware portability.
Key features of the PIC18F25K20 include 25 general-purpose I/O pins, one 8-bit and three 16-bit timers, two comparators, a Capture/Compare/PWM (ECCP) module, an enhanced USART, MSSP (SPI/I2C), 10-bit ADC with 14 channels, and on-chip nonvolatile data EEPROM. The wide 1.8 V to 3.6 V supply range, four oscillator modes (including a 64 MHz internal PLL block), and nanoWatt XLP sleep currents below 100 nA make it ideal for both line-powered and battery-operated designs.
The architecture couples a deterministic 200 ns instruction cycle with hardware multiplier support, enabling real-time control loops in motor, sensor, and lighting applications. Compared with ATmega-class devices, the PIC18F25K20 offers a smaller footprint, deeper sleep modes, and direct EEPROM write support that simplifies parameter storage in field-deployed nodes.
Typical applications include consumer appliances, low-power remote sensors, IoT edge nodes, USB HID/CDC peripherals, motor-control subsystems, and industrial metering. Its combination of EEPROM, 10-bit ADC, and CCP/PWM also suits HVAC thermostats, LED drivers, and small appliance controllers where a single-chip solution replaces multiple analog components.
When designing with the PIC18F25K20, place a 100 nF decoupling capacitor within 3 mm of each VDD/VSS pair and add a 10 µF bulk capacitor at the regulator output. Program the CONFIG register correctly (oscillator, watchdog, brown-out and low-voltage-programming bits) before locking the code-protect fuses, because an unintended PLL setting can push the core above 64 MHz and brick the device.
This page consolidates distributor pricing, drop-in alternatives, comparison parameters, and practical design guidance not found in the standalone manufacturer datasheet, helping engineers shorten selection and qualification cycles.
Drop-in alternatives for PIC18F25K20-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 PIC18F25K20-I/SS (same form factor and footprint) — differing in Timers, ADC, Package, Operating Temperature, Core.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PIC18F25K22-I/SS
✅ Drop-In✓ In Stock
$1.92 / Unit
View Datasheet →PIC18F26K20-I/SS
✅ Drop-In📋 Reference alternative (not in catalog)
PIC18F24K20-I/SS
✅ Drop-In✓ In Stock
$1.92 / Unit
View Datasheet →PIC18F25K20-E/SS
✅ Drop-In✓ In Stock
$2.55 / Unit
View Datasheet →PIC18F25K20-I/SO
✅ Drop-In✓ In Stock
$2.55 / Unit
View Datasheet →PIC18F23K20-I/SS
✅ Drop-In✓ In Stock
$1.65 / Unit
View Datasheet →PIC18F25K20-I/SS Maximum Ratings & Electrical Characteristics
| Core | PIC18 8-bit RISC (Harvard) |
| Program Memory | 32 KB Flash |
| RAM | 1536 bytes |
| EEPROM | 256 bytes |
| Max CPU Speed | 64 MHz (16 MIPS, 200 ns instruction cycle) |
| Supply Voltage (VDD) | 1.8 V to 3.6 V |
| I/O Pins | 25 |
| ADC | 10-bit, up to 14 channels |
| Timers | 1 x 8-bit, 3 x 16-bit |
| Capture/Compare/PWM | 1 ECCP + 2 CCP |
| Communication | EUSART, MSSP (SPI / I2C) |
| Comparators | 2 |
| Package | 28-SSOP (5.30 mm body) |
| Operating Temperature | -40 C to +85 C (Industrial) |
| Low-Power Technology | nanoWatt XLP (sleep current < 100 nA typical) |
| RoHS Status | Compliant |
| Programming | ICSP (In-Circuit Serial Programming) |
PIC18F25K20-I/SS Pin Configuration
| Pin 1 | RA7/AN7/OSC1/CLKIN — GPIO RA7 / Analog AN7 / Oscillator input |
| Pin 2 | RA0/AN0 — GPIO RA0 / Analog AN0 |
| Pin 3 | RA1/AN1 — GPIO RA1 / Analog AN1 |
| Pin 4 | RA2/AN2/VREF- — GPIO RA2 / Analog AN2 / ADC VREF- |
| Pin 5 | RA3/AN3/VREF+ — GPIO RA3 / Analog AN3 / ADC VREF+ |
| Pin 6 | RA4/T0CKI/C1OUT — GPIO RA4 / Timer0 clock / Comparator 1 output |
| Pin 7 | RA5/AN4/SS/HLVDIN/C2OUT — GPIO RA5 / Analog AN4 / SPI SS / HLVD / Comparator 2 output |
| Pin 8 | VDD — Positive supply voltage |
| Pin 9 | VSS — Ground reference |
| Pin 10 | RA6/AN5/OSC2/CLKOUT — GPIO RA6 / Analog AN5 / Oscillator output |
| Pin 11 | RC0/T1OSO/T1CKI — GPIO RC0 / Timer1 oscillator out / Timer1 clock |
| Pin 12 | RC1/T1OSI/CCP2 — GPIO RC1 / Timer1 oscillator in / CCP2 |
| Pin 13 | RC2/P1A/CCP1 — GPIO RC2 / PWM output / CCP1 |
| Pin 14 | RC3/SCK/SCL — GPIO RC3 / SPI clock / I2C clock |
| Pin 15 | RC4/SDI/SDA — GPIO RC4 / SPI data in / I2C data |
| Pin 16 | RC5/SDO — GPIO RC5 / SPI data out |
| Pin 17 | RC6/TX/CK — GPIO RC6 / USART TX / USART clock |
| Pin 18 | RC7/RX/DT — GPIO RC7 / USART RX / USART data |
| Pin 19 | VSS — Ground reference |
| Pin 20 | VDD — Positive supply voltage |
| Pin 21 | RB0/INT0/AN12 — GPIO RB0 / External interrupt 0 / Analog AN12 |
| Pin 22 | RB1/INT1/AN10 — GPIO RB1 / External interrupt 1 / Analog AN10 |
| Pin 23 | RB2/INT2/AN8 — GPIO RB2 / External interrupt 2 / Analog AN8 |
| Pin 24 | RB3/INT3/CCP2 — GPIO RB3 / External interrupt 3 / CCP2 alt |
| Pin 25 | RB4/KBI0/AN9 — GPIO RB4 / Interrupt-on-change / Analog AN9 |
| Pin 26 | RB5/KBI1/PGM — GPIO RB5 / Interrupt-on-change / LVP program |
| Pin 27 | RB6/KBI2/PGC — GPIO RB6 / Interrupt-on-change / ICD clock |
| Pin 28 | RB7/KBI3/PGD — GPIO RB7 / Interrupt-on-change / ICD data |
Typical Applications
PIC18F25K20-I/SS is suitable for 7 applications: Battery-Powered IoT Sensor Nodes, Consumer Appliance Control, HVAC Thermostats and Building Controls, Automotive Body and Lighting Modules, USB HID / CDC Peripherals, Industrial Metering and Data Loggers, Small Motor Control (BLDC / Stepper).
Battery-Powered IoT Sensor Nodes
The PIC18F25K20-I/SS is a strong fit for battery-powered IoT sensor nodes thanks to its nanoWatt XLP sleep current below 100 nA and 1.8 V to 3.6 V wide VDD range, which aligns with single-cell Li-ion and dual-AA chemistries without a boost regulator. Its 64 MHz CPU delivers 16 MIPS, enough for on-sensor edge filtering and protocol handling (I2C sensor reads, SPI radio uplink) before the device returns to deep sleep. The 25 GPIO channels easily accommodate a multi-sensor hub with interrupt wake sources, while the 10-bit ADC handles analog transducers such as temperature, light, or gas sensors. Designers typically achieve 1-3 year battery life on a single CR2032 by spending >99% of the time in retention sleep and waking only every few seconds. Compared with ATmega-based designs, the PIC18F25K20 typically draws 5-10x less sleep current for equivalent workloads.
Recommended
Consumer Appliance Control
Consumer appliance control boards (coffee machines, washing machines, microwave ovens, air purifiers) benefit from the PIC18F25K20-I/SS's 32 KB Flash for state-machine firmware plus a 10-bit ADC with 14 channels that reads multiple analog sensors (temperature, humidity, water level) without external multiplexer. The 1 ECCP plus 2 CCP modules drive triac-fired heater elements, BLDC motors, or PWM-controlled solenoid valves directly, while two analog comparators implement over-current and zero-cross detection with zero software overhead. The wide 1.8 V to 3.6 V supply lets the same firmware run from 3.3 V LDO or 2-cell AA backup. Internal EEPROM (256 bytes) stores user preferences and calibration data without external NVRAM, reducing BOM cost in cost-sensitive appliance SKUs.
Recommended
HVAC Thermostats and Building Controls
The PIC18F25K20-I/SS is well-suited to HVAC thermostat and building automation control because its 10-bit ADC handles multiple thermistor inputs (room, return-air, supply-air, outdoor remote sensor) and the MSSP supports I2C for external RTC and EEPROM. nanoWatt XLP deep sleep below 100 nA means thermostats powered from 24 VAC via a small buck converter stay within Energy Star standby budgets. The enhanced USART enables direct EIA-485 connection to BACnet or Modbus building-automation networks, while the ECCP module drives the furnace call relay and fan stage with hardware PWM and dead-band control. Internal EEPROM stores user schedules across power outages without an external NVRAM IC.
Recommended
Automotive Body and Lighting Modules
In automotive body control units, interior lighting controllers, and instrument cluster peripherals, the PIC18F25K20-I/SS's Industrial -40 C to +85 C temperature grade and wide supply tolerance handle under-hood and cabin thermal swings. Its 25 GPIO pins drive multiple LED strings with PWM dimming via the ECCP module at hardware resolution without CPU overhead, freeing the 16 MIPS core for CAN-style messaging over a UART-to-CAN transceiver pair. The 256-byte on-chip EEPROM stores trim and lifetime counters that survive key-off battery disconnect. For harsher under-hood zones, drop in the PIC18F25K20-E/SS (Extended -40 C to +125 C) with identical firmware and footprint.
Recommended
USB HID / CDC Peripherals
The PIC18F25K20-I/SS powers USB Human Interface Devices and CDC serial peripherals through its MSSP (SPI) bus plus a 5 V-tolerant GPIO structure when paired with a 3.3 V LDO. Its 16 MIPS throughput handles USB 1.1 low-speed HID polling at the firmware level using the same PIC18 USB framework that Microchip ships for the family, while 1536 bytes of SRAM hold HID report buffers without dropping packets. The 10-bit ADC supports analog joystick axes, and the ECCP module drives vibration motors or LED feedback rings. Compared with ATmega32U4 designs, the PIC18F25K20 typically yields 15-20% lower active power at the same HID polling rate, extending battery life in wireless HID dongles.
Recommended
Industrial Metering and Data Loggers
The PIC18F25K20-I/SS integrates seamlessly into industrial metering and data logger modules where 32 KB Flash accommodates Modbus, DNP3, or proprietary stack libraries, and the 256-byte EEPROM records calibration constants and runtime counters without external NVRAM. The 10-bit ADC with 14 channels handles pulse-train flow sensors, 4-20 mA loops, and bridge-type pressure transducers via on-chip PGIA, while the ECCP module measures frequency by capture. nanoWatt XLP deep sleep (below 100 nA) lets battery-backed meters survive years of field deployment without maintenance. Its Industrial -40 C to +85 C temperature grade and 3.6 V supply ceiling tolerate harsh factory-floor wiring.
Recommended
Small Motor Control (BLDC / Stepper)
Small brushless DC and stepper motor controllers up to a few hundred watts use the PIC18F25K20-I/SS's ECCP module to generate 6-step or sinusoidal PWM at hardware resolution without CPU jitter. The 64 MHz core closes current and RPM loops in firmware while the comparators provide hardware over-current protection that latches the PWM outputs in microseconds. With 32 KB Flash, the same firmware carries the speed PI loop, soft-start ramp, and stall-detection state machine, eliminating an external gate-driver MCU. nanoWatt XLP idle modes keep the standby current low when the motor is parked, which matters in battery-powered robotics and e-bike accessory designs.
Recommended
Recommended Products Summary
Engineering reference data for PIC18F25K20-I/SS — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC18F25K22-I/SS | PIC18F26K20-I/SS | PIC18F24K20-I/SS | PIC18F25K20-E/SS | PIC18F23K20-I/SS |
|---|---|---|---|---|---|---|
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Package | 28-SSOP | 28-SSOP | 28-SSOP | 28-SSOP | 28-SSOP | 28-SSOP |
| Program Flash | 32 KB | 32 KB | 64 KB | 16 KB | 32 KB | 8 KB |
| SRAM | 1536 B | 1536 B | 3936 B | 768 B | 1536 B | 512 B |
| EEPROM | 256 B | 256 B | 1024 B | 256 B | 256 B | 256 B |
| Max CPU Speed | 64 MHz / 16 MIPS | 64 MHz / 16 MIPS | 64 MHz / 16 MIPS | 64 MHz / 16 MIPS | 64 MHz / 16 MIPS | 64 MHz / 16 MIPS |
| I/O Pins | 25 | 25 | 25 | 25 | 25 | 25 |
| Supply Voltage | 1.8 V to 3.6 V | 1.8 V to 3.6 V | 1.8 V to 3.6 V | 1.8 V to 3.6 V | 1.8 V to 3.6 V | 1.8 V to 3.6 V |
| Temperature Grade | -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 |
| Pin-to-Pin Compatible | Yes (reference) | Yes | Yes | Yes | Yes | Yes |
Key Differentiators
- Strongest combination of nanoWatt XLP deep-sleep current and 64 MHz throughput in the PIC18 K20 family (vs PIC18F25K22-I/SS)
- Higher memory ceiling within the same 28-SSOP footprint (vs PIC18F24K20-I/SS)
- Industrial temperature grade with on-chip EEPROM data retention (vs PIC18F25K20-I/SO)
- Direct compatibility with PICkit 5, MPLAB X IDE, and MCC code configurator (vs PIC18F25K20-E/SS (Extended temperature))
Design Notes
Decoupling is critical for the PIC18F25K20's 64 MHz core. Place a 100 nF X7R ceramic capacitor within 3 mm of each VDD/VSS pin pair (pins 8-9 and 19-20 on 28-SSOP), and add a single 10 uF bulk capacitor at the regulator output. For battery-powered designs using nanoWatt XLP sleep below 1 uA, ensure the regulator's quiescent current is below 500 nA (e.g., MCP1700) to preserve battery life. Place a 1 MOhm pull-up on MCLR (pin 1) to keep the device out of reset during VDD ramp.
Configuration bits must be programmed correctly before the part will operate. The most common mistakes are (1) leaving the PLL enabled while selecting an external oscillator, which forces the CPU above 64 MHz and bricks the part, (2) enabling low-voltage programming (LVP) without the PGECx/PGEDx pins reserved, which prevents subsequent ICSP sessions, and (3) forgetting to disable the watchdog timer (WDT) when using the internal LFINTOSC, which causes unexpected resets. Always read CONFIG1H through CONFIG4L back with the debugger after programming.
For 28-SSOP layout, route the ICSP pins (RB6/PGD, RB7/PGC) to a 6-pin header or test pad so the device can be programmed and debugged in-circuit using a PICkit 5 or ICD 4. Keep traces from RC3 (SCK/SCL) and RC4 (SDI/SDA) short (<25 mm) and add 4.7 kOhm pull-ups on I2C lines if used. The exposed die pad is not present on 28-SSOP, so no thermal copper pour is required, but a ground pour under the part improves EMI immunity for the ADC channels.
The 10-bit ADC on PIC18F25K20 achieves best linearity when the source impedance is below 10 kOhm and the acquisition time is at least 2.45 us. Add an external 100 nF ceramic capacitor directly at the analog pin if the source impedance exceeds 5 kOhm (for example, when reading a remote thermistor through long cable). Use VREF+ (RA3) tied to a stable 3.0 V reference (e.g., MCP1525) instead of VDD for measurements requiring better than 1% absolute accuracy across temperature.
The PIC18F25K20 is a low-power CMOS device that dissipates well under 100 mW even at full 64 MHz operation. In 28-SSOP (theta_JA approximately 90 C/W), maximum junction temperature is reached only at extreme ambient plus load combinations. No heatsink or thermal copper pour is required for typical embedded use; however, in enclosed automotive cabin installations at +85 C ambient, verify that the total device current (CPU + peripherals + I/O drive) stays below 30 mA to maintain the 10-year reliability target.
Compliance Information
RoHS and REACH compliance per Microchip product page; lead-free matte-tin finish; halogen-free molding compound. Not AEC-Q100 qualified - for AEC-Q100 automotive grade consider PIC18F25K20-I/SSVAO factory pre-screened variants. Conflict minerals declaration filed under Microchip's Dodd-Frank reporting.
