PIC18F24K20-E/SO - 16KB Flash 8-bit MCU 48MHz 28-SOIC | Microchip
MPN: PIC18F24K20-E/SO ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $4.2 | $4.20 |
| 10 | $3.82 | $38.20 |
| 100 | $3.45 | $345.00 |
| 500 | $3.03 | $1,515.00 |
| 1,000 | $2.78 | $2,780.00 |
PIC18F24K20-E/SO Overview
An 8-bit microcontroller (MCU) is a programmable computing core that integrates a CPU, non-volatile program memory, volatile data memory, and peripheral interfaces onto a single silicon die. Within the broader taxonomy, the PIC18F24K20 belongs to the flash microcontroller family (program memory hierarchy), which itself sits under the RISC CPU category, the embedded controller class, and ultimately the semiconductor / integrated circuit root. The PIC18F24K20 specifically is part of Microchip's nanoWatt XLP extreme-low-power platform, with multiple power-managed modes that allow battery-powered applications to quiesce below 1 microamp on the real-time clock.
Key features include 16 KB flash program memory, 768 bytes of SRAM, 256 bytes of EEPROM, a 10-bit ADC with up to 14 channels, 25 digital I/O pins, dual analog comparators, an Enhanced USART, two MSSP ports supporting SPI and I2C, and four 8-bit / four 16-bit timers. The 48 MHz internal oscillator and 64 MHz PLL-derived system clock give 16 MIPS throughput with single-cycle 200 ns instruction execution. On-chip peripherals include the ECAN module (not present on K20 parts), self-programming flash, and an ICD/ICSP debug interface compatible with MPLAB tools.
Architecturally, the part uses an enhanced Harvard RISC core with optional extended instruction set for C-compiler code density, an 8-bit data path, and 16-bit instruction words. The XLP nanoWatt technology combines switchable core clock dividers, low-power timer1 RTC operation, and selective peripheral gating, allowing deep-sleep currents in the sub-microamp range when used with the on-chip low-power oscillator.
Typical applications include industrial sensor conditioning, low-power remote keyless entry, battery-backed instrumentation, HVAC controllers, low-cost motor control, USB-to-UART bridges (with external MCU-managed USB), and portable medical accessories. The 28-SOIC package allows hand-prototyping and hand-repair, while the same silicon is offered in 28-QFN (ML), 28-SPDIP (SP), and 28-QFP variants for layout flexibility.
When designing with this part, always reserve the ICSPCLK/ICSPDAT pins for in-circuit serial programming; pin RB6/RB7 are dual-purpose and cannot be used as general I/O in a final production board without losing field-upgrade capability. Place a 100 nF decoupling capacitor within 5 mm of the VDD pin and a bulk capacitor (typically 1 uF to 10 uF) on the AVDD rail close to the analog supply pin to keep the ADC noise floor within datasheet spec.
This page synthesizes distributor pricing, drop-in alternatives, and practical design notes not found in the manufacturer datasheet, giving the engineer a single decision-ready reference.
Drop-in alternatives for PIC18F24K20-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 PIC18F24K20-E/SO (same form factor and footprint) — differing in Package, Timers, ADC, Core Architecture, MSL Level.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PIC18F24K20-I/SO
✅ Drop-In📋 Reference alternative (not in catalog)
PIC18F24K20-E/SP
✅ Drop-In ⚠️ Specs Unverified📋 Reference alternative (not in catalog)
PIC18F24K20-E/ML
✅ Drop-In ⚠️ Specs Unverified✓ In Stock
$2.45 / Unit
View Datasheet →PIC18F25K20-E/SO
✅ Drop-In📋 Reference alternative (not in catalog)
PIC18F23K20-E/SO
✅ Drop-In ⚠️ Specs Unverified✓ In Stock
$1.94 / Unit
View Datasheet →PIC18F24K20-E/SO Maximum Ratings & Electrical Characteristics
| Core Architecture | PIC18 Enhanced RISC (Harvard) |
| Bit Width | 8-bit |
| Program Memory Type | Flash |
| Program Memory Size | 16 KB (8K x 16) |
| SRAM | 768 bytes |
| EEPROM | 256 bytes |
| Maximum CPU Frequency | 48 MHz (FOSC); 64 MHz with PLL |
| MIPS | 16 MIPS |
| Supply Voltage (VDD) | 1.8 V to 3.6 V (F-series); datasheet extends to 5.5 V in some modes |
| I/O Pins | 25 |
| ADC | 10-bit, up to 14 channels |
| Timers | 4 x 8-bit / 4 x 16-bit (varies by family documentation) |
| Communication Interfaces | Enhanced USART, 2x MSSP (SPI/I2C) |
| Operating Temperature (E suffix) | -40C to +125C (Extended) |
| Package | 28-SOIC (0.295 inch / 7.50 mm width) |
| Mounting Type | Surface Mount |
| RoHS Status | Compliant |
| MSL Level | 1 (unlimited floor life at <30C/85% RH) |
| Instruction Set | Standard + optional extended |
| Low-Power Technology | nanoWatt XLP |
PIC18F24K20-E/SO Pin Configuration
| Pin 1 | MCLR/VPP/RE3 — Master Clear / Programming Voltage / PORTE bit 3 |
| Pin 2 | RA0/AN0/CVREF — PORTA bit 0 / Analog input 0 / Comparator Voltage Reference |
| Pin 3 | RA1/AN1/C1IN-/C2IN- — PORTA bit 1 / Analog input 1 / Comparator 1/2 negative input |
| Pin 4 | RA2/AN2/VREF-/CVREF — PORTA bit 2 / Analog input 2 / ADC VREF- / CVREF |
| Pin 5 | RA3/AN3/VREF+ — PORTA bit 3 / Analog input 3 / ADC VREF+ |
| Pin 6 | RA4/T0CKI/C1OUT — PORTA bit 4 / Timer0 clock / Comparator 1 output |
| Pin 7 | RA5/AN4/SS1/C2OUT — PORTA bit 5 / Analog input 4 / SSP1 slave select / Comparator 2 output |
| Pin 8 | VSS — Ground reference |
| Pin 9 | RA7/OSC1/CLKIN — PORTA bit 7 / Oscillator crystal 1 / External clock input |
| Pin 10 | RA6/OSC2/CLKOUT — PORTA bit 6 / Oscillator crystal 2 / Clock output |
| Pin 11 | RC0/T1OSO/T1CKI — PORTC bit 0 / Timer1 oscillator output / Timer1 clock input |
| Pin 12 | RC1/T1OSI/CCP2 — PORTC bit 1 / Timer1 oscillator input / CCP2 |
| Pin 13 | RC2/CCP1/P1A — PORTC bit 2 / CCP1 / PWM output P1A |
| Pin 14 | RC3/SCK1/SCL1 — PORTC bit 3 / SPI1 clock / I2C1 clock |
| Pin 15 | RC4/SDI1/SDA1 — PORTC bit 4 / SPI1 data in / I2C1 data |
| Pin 16 | RC5/SDO1 — PORTC bit 5 / SPI1 data out |
| Pin 17 | RC6/TX1/CK1 — PORTC bit 6 / EUSART1 transmit / EUSART1 clock |
| Pin 18 | RC7/RX1/DT1 — PORTC bit 7 / EUSART1 receive / EUSART1 data |
| Pin 19 | VSS — Ground reference |
| Pin 20 | VDD — Positive supply voltage |
| Pin 21 | RB0/AN12/INT0/FLT0 — PORTB bit 0 / Analog input 12 / External interrupt 0 / PWM fault |
| Pin 22 | RB1/AN10/INT1 — PORTB bit 1 / Analog input 10 / External interrupt 1 |
| Pin 23 | RB2/AN8/INT2 — PORTB bit 2 / Analog input 8 / External interrupt 2 |
| Pin 24 | RB3/AN9/CCP2 — PORTB bit 3 / Analog input 9 / CCP2 |
| Pin 25 | RB4/AN11/KBI0 — PORTB bit 4 / Analog input 11 / Keyboard interrupt 0 |
| Pin 26 | RB5/KBI1 — PORTB bit 5 / Keyboard interrupt 1 |
| Pin 27 | RB6/KBI2/PGC — PORTB bit 6 / Keyboard interrupt 2 / ICSP clock |
| Pin 28 | RB7/KBI3/PGD — PORTB bit 7 / Keyboard interrupt 3 / ICSP data |
Typical Applications
PIC18F24K20-E/SO is suitable for 6 applications: Industrial Sensor Conditioning and Acquisition, Low-Power Remote Keyless Entry and Battery Devices, HVAC and Building Automation Controllers, Portable Medical Accessories and Wellness Devices, Low-Cost Motor Control and BLDC Commutation, USB-to-UART Bridge and Field-Programmable Peripherals.
Industrial Sensor Conditioning and Acquisition
The PIC18F24K20-E/SO fits industrial sensor acquisition nodes thanks to its 10-bit ADC with up to 14 channels, 16 MIPS CPU performance, and nanoWatt XLP deep-sleep modes below 1 uA. Placed on a sensor PCB with strain-gauge or RTD front-end, the MCU converts analog signals at up to 100 ksps aggregate while its on-chip EUSART streams results to a host controller. The Extended -40C to +125C temperature grade is essential for unheated factory cabinets, outdoor installations, and motor-control enclosures where derating or thermal shutdown is unacceptable.
Recommended
Low-Power Remote Keyless Entry and Battery Devices
The PIC18F24K20-E/SO is well-matched to battery-powered remote keyless entry fobs and similar sub-1 uA sleep applications, where nanoWatt XLP technology, Timer1 RTC operation, and selective peripheral gating enable years of operation from a single CR2032 coin cell. The MCU wakes on external interrupt or RTC match, performs authentication or measurement, transmits via OOK/FSK, then returns to sleep in tens of microseconds. The 28-SOIC package supports hand-repairable fob designs and small form factors where QFN rework is impractical.
Recommended
HVAC and Building Automation Controllers
The PIC18F24K20-E/SO suits HVAC zone controllers and building automation nodes where 16 MIPS CPU throughput handles BACnet, Modbus, or proprietary protocols, and 25 I/O pins drive triacs, relays, and 4-20 mA loops. Its -40C to +125C extended temperature range handles plenum-temperature environments and rooftop mounting where industrial-grade parts derate. The on-chip 10-bit ADC reads thermistor, humidity, and pressure sensors directly; PWM outputs drive proportional valves and damper actuators without external motor controllers.
Recommended
Portable Medical Accessories and Wellness Devices
The PIC18F24K20-E/SO is well-suited to portable medical peripherals such as pill-box reminders, spirometer accessories, and pulse-oximeter interfaces where ultra-low sleep current, deterministic real-time behavior, and the -E extended temperature range are required. Its 16 MIPS CPU performs sensor fusion and basic filtering while the nanoWatt XLP platform enables multi-month battery life on two AAA cells. The EUSART interfaces with Bluetooth or Wi-Fi companion modules; the 10-bit ADC reads pulse oximetry photodiode signals after external amplification.
Recommended
Low-Cost Motor Control and BLDC Commutation
The PIC18F24K20-E/SO drives low-cost BLDC, brushed DC, and stepper motors in appliance and small-pump applications, where its 16 MIPS throughput, configurable PWM, and 10-bit ADC enable sensorless back-EMF commutation and closed-loop speed control. The Extended -40C to +125C grade handles motor-mounted PCBs where self-heating and ambient temperature combine. The 28-SOIC package supports through-hole-friendly power stages using discrete MOSFETs and gate drivers, with the MCU providing direction, speed, current sensing, and fault handling.
Recommended
USB-to-UART Bridge and Field-Programmable Peripherals
The PIC18F24K20-E/SO works as a USB-to-UART bridge (with external USB PHY) or as a field-configurable peripheral controller where 16 KB of flash stores command interpreters, scripting engines, or Modbus gateway logic. The on-chip EUSART and MSSP ports provide SPI and I2C for downstream sensor and actuator networks. Self-programming flash enables firmware updates in the field, while the ICSP interface supports in-circuit debug with MPLAB PICkit 5. The Extended temperature grade fits outdoor and industrial installations.
Recommended
Recommended Products Summary
Engineering reference data for PIC18F24K20-E/SO — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC18F24K20-I/SO | PIC18F25K20-E/SO | PIC18F23K20-E/SO |
|---|---|---|---|---|
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Package | 28-SOIC (0.295 inch / 7.50 mm) | 28-SOIC (0.295 inch) - same | 28-SOIC (0.295 inch) - same | 28-SOIC (0.295 inch) - same |
| Program Memory | 16 KB Flash | 16 KB Flash | 32 KB Flash (+100%) | 8 KB Flash (-50%) |
| SRAM | 768 bytes | 768 bytes | 1.5 KB (+95%) | 512 bytes (-33%) |
| EEPROM | 256 bytes | 256 bytes | 256 bytes | 256 bytes |
| Maximum CPU Frequency | 48 MHz (64 MHz with PLL) | 48 MHz (64 MHz PLL) | 48 MHz (64 MHz PLL) | 48 MHz (64 MHz PLL) |
| Temperature Grade | Extended -40C to +125C | Industrial -40C to +85C | Extended -40C to +125C | Extended -40C to +125C |
| I/O Pins | 25 | 25 | 25 | 25 |
| ADC | 10-bit, 14 channels | 10-bit, 14 channels | 10-bit, 14 channels | 10-bit, 11 channels |
| Low-Power Technology | nanoWatt XLP | nanoWatt XLP | nanoWatt XLP | nanoWatt XLP |
Key Differentiators
- Extended -40C to +125C temperature grade at industrial pricing (vs PIC18F24K20-I/SO)
- nanoWatt XLP deep-sleep current below 100 nA (vs PIC18F23K20-E/SO)
- Hand-repairable 28-SOIC package for prototyping and field service (vs PIC18F24K20-E/ML (28-QFN))
Design Notes
Decouple VDD with a 100 nF ceramic capacitor placed within 5 mm of the supply pin and a bulk 1 uF to 10 uF electrolytic or tantalum capacitor on the same rail. For the analog AVDD supply (if separated), use a low-noise LDO such as MCP1700 with its own 100 nF bypass; ADC accuracy depends on clean analog rail. The nanoWatt XLP sleep current is below 100 nA when using the internal low-power RC oscillator, so verify the chosen regulator quiescent current is also below this floor to preserve battery life.
Keep the ICSP clock (PGC, pin 27) and ICSP data (PGD, pin 28) traces short, isolated from switching power traces, and pulled to known states during reset to prevent unintended entry into programming mode. Reserve a 6-pin ICSP header (or 0.1 inch pads) on the PCB for production programming and field debug using MPLAB PICkit 5. For mixed-signal designs, split the ground plane under the analog and digital sections with a single-point bridge near the MCU VSS pin to keep ADC noise below 1 LSB.
Do not connect RB6/RB7 to external circuitry that fights the ICSP driver; these pins are shared with ICSP clock and data. Avoid using the MCLR pin as a general digital input - configure RE3 only after disabling the MCLR function via CONFIG3H. When migrating from PIC18F24K20 to PIC18F25K20, verify interrupt vector remapping, since the larger flash part may relocate some interrupt service routine addresses. Always set the CONFIG registers for brown-out reset and watchdog timer to prevent firmware lockup in noisy industrial environments.
For SPI buses running above 4 MHz, keep the SCK, SDO, and SDI traces matched in length and routed over a continuous ground plane; add 22-33 ohm series termination at the MCU end to dampen reflections. The MSSP I2C lines require 2.7 kohm to 10 kohm pull-ups depending on bus capacitance and clock speed; do not exceed 400 kHz without verifying rise-time compliance. For EUSART RS-485 half-duplex networks, drive the DE/RE pin from a spare GPIO with at least 100 us setup before the first transmitted byte.
Compliance Information
RoHS and REACH compliant per Microchip product page and distributor listings. -E temperature grade is industrial-extended, not AEC-Q100 automotive qualified - choose a K22 or K40 automotive variant for AEC-Q100 designs. Lead-free and halogen-free per Microchip packaging material declarations.
