PIC18F24K50-I/SO - 8-bit MCU, 16KB Flash, 48MHz, USB | Microchip
MPN: PIC18F24K50-I/SO ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $3.18 | $3.18 |
| 10 | $2.86 | $28.60 |
| 100 | $2.54 | $254.00 |
| 500 | $2.28 | $1,140.00 |
| 1,000 | $2.05 | $2,050.00 |
PIC18F24K50-I/SO Overview
An 8-bit microcontroller (MCU) is a small, self-contained computer-on-a-chip that integrates a CPU, RAM, non-volatile program memory (Flash/ROM), peripherals, and I/O onto a single die. The PIC18 family uses a RISC-based Harvard architecture with 16-bit instructions and 8-bit data path, sitting between baseline PIC10/12/16 parts (smaller, slower) and PIC24/dsPIC parts (16-bit, higher performance). The PIC18F24K50 adds integrated USB hardware, eliminating the need for an external transceiver chip, and is positioned in the low-power, mixed-signal tier of the PIC18 lineup.
Key features include 25 general-purpose I/O pins with individual weak pull-ups, a 10-bit ADC with up to 14 channels, two analog comparators, two 8-bit timers plus one 16-bit timer, two PWM modules, MSSP (SPI/I2C), enhanced USART, and a charge time measurement unit (CTMU) for capacitive touch. The integrated USB 2.0 full-speed PHY supports both device and limited host/OTG modes and pairs with the free Microchip USB stack. XLP technology delivers typical sleep currents below 100 nA with retention, plus a real-time clock calendar (RTCC) that runs from a secondary 32 kHz source.
The architecture pairs a PIC18 CPU core with a Harvard bus (separate program and data paths), an 8-deep hardware stack for subroutines, and a vectored interrupt controller. The integrated 3.3V LDO regulator with on-chip detection allows single-rail operation from 2.3V to 5.5V, switching internally to the LDO when VDD is below the USB-required threshold. The ADC and comparators operate from an internal bandgap reference for stable conversions across temperature.
Typical applications include USB peripherals (HID, CDC, MSD), low-power sensor nodes with USB enumeration for charging/data, capacitive touch user interfaces, battery-powered industrial data loggers, and consumer products requiring firmware-updatable USB connectivity. Designers favor this part when they want to skip the external USB PHY and minimize BOM cost while retaining modern low-power operation. Compared with the PIC18F2450/2550 series, the K50 family adds XLP deep-sleep, more ADC channels, and the internal LDO for USB operation from a single supply.
Drop-in alternatives for PIC18F24K50-I/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 PIC18F24K50-I/SO (same form factor and footprint) — differing in ADC, Package, Timers, I/O Pins, Operating Temperature.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PIC18F24K50-I/SO
✅ Drop-In✓ In Stock
$2.05 / Unit
View Datasheet →PIC18F24K50-E/SO
✅ Drop-In📋 Reference alternative (not in catalog)
PIC18F24K50T-I/SO
✅ Drop-In✓ In Stock
$1.98 / Unit
View Datasheet →PIC18F24K40-I/SO
✅ Drop-In📋 Reference alternative (not in catalog)
PIC18F24K42-I/SS
✅ Drop-In✓ In Stock
$1.53 / Unit
View Datasheet →PIC18F24K40-E/SO
✅ Drop-In✓ In Stock
$1.2 / Unit
View Datasheet →PIC18F24K50-I/SO Maximum Ratings & Electrical Characteristics
| Core Architecture | PIC18 (8-bit RISC, Harvard) |
| Program Memory (Flash) | 16 KB (8K x 16) |
| Data SRAM | 2 KB |
| EEPROM | 256 bytes |
| Maximum CPU Speed | 48 MHz (16 MIPS) |
| Supply Voltage (VDD) | 2.3 V to 5.5 V |
| Operating Temperature | -40 C to +85 C (industrial) |
| Package | 28-pin SOIC (300 mil) |
| I/O Pins | 25 |
| ADC | 10-bit, up to 14 channels |
| USB | USB 2.0 Full-Speed (12 Mbps), integrated PHY |
| Timers | Two 8-bit, one 16-bit |
| PWM Modules | 2 (CCP + ECCP) |
| Communication | MSSP (SPI/I2C), Enhanced USART |
| Comparators | 2 analog comparators |
| CTMU | Charge Time Measurement Unit (capacitive touch) |
| RTCC | Real-Time Clock Calendar with 32 kHz domain |
| Low-Power Technology | nanoWatt XLP |
| RoHS Status | Compliant |
PIC18F24K50-I/SO Pin Configuration
| Pin 1 | MCLR/VPP/RE3 — Master Clear (reset) input or ICSP voltage / digital I/O RE3 |
| Pin 2 | RA0/AN0 — PORTA bit 0 / analog input AN0 |
| Pin 3 | RA1/AN1 — PORTA bit 1 / analog input AN1 |
| Pin 4 | RA2/AN2 — PORTA bit 2 / analog input AN2 |
| Pin 5 | RA3/AN3/VREF+ — PORTA bit 3 / analog input AN3 / positive voltage reference |
| Pin 6 | RA4/AN4/T0CKI — PORTA bit 4 / analog input AN4 / Timer0 clock input |
| Pin 7 | RA5/AN5/SS — PORTA bit 5 / analog input AN5 / SPI slave select |
| Pin 8 | VSS — Ground reference |
| Pin 9 | OSC1/CLKIN/RA7 — External oscillator input / clock in / PORTA bit 7 |
| Pin 10 | OSC2/CLKOUT/RA6 — External oscillator output / clock out / PORTA bit 6 |
| Pin 11 | RC0/SOSO — PORTC bit 0 / SOSC oscillator output |
| Pin 12 | RC1/SOSI — PORTC bit 1 / SOSC oscillator input |
| Pin 13 | RC2/CCP1 — PORTC bit 2 / Capture/Compare/PWM1 |
| Pin 14 | D- — USB D- data line (requires series 27 ohm if VDD > 3.3V) |
| Pin 15 | D+ — USB D+ data line |
| Pin 16 | VBUS — USB VBUS sense input |
| Pin 17 | RC6/TX/CK — PORTC bit 6 / USART TX / clock |
| Pin 18 | RC7/RX/DT — PORTC bit 7 / USART RX / data |
| Pin 19 | VSS — Ground reference |
| Pin 20 | VDD — Positive supply voltage 2.3V to 5.5V |
| Pin 21 | RB0/AN12/INT0 — PORTB bit 0 / analog AN12 / external interrupt 0 |
| Pin 22 | RB1/AN10 — PORTB bit 1 / analog AN10 |
| Pin 23 | RB2/AN8 — PORTB bit 2 / analog AN8 |
| Pin 24 | RB3/AN9 — PORTB bit 3 / analog AN9 / ICSP PGED |
| Pin 25 | RB4/AN11 — PORTB bit 4 / analog AN11 |
| Pin 26 | RB5/AN13 — PORTB bit 5 / analog AN13 / ICSP PGEC |
| Pin 27 | RB6/ICSPCLK — PORTB bit 6 / ICSP clock |
| Pin 28 | RB7/ICSPDAT — PORTB bit 7 / ICSP data |
Typical Applications
PIC18F24K50-I/SO is suitable for 6 applications: USB HID Peripherals, Low-Power Sensor Data Loggers, Capacitive Touch User Interfaces, USB Charging and Battery Monitors, Industrial USB-to-Serial Bridges, Consumer Audio/Volume Controllers with USB.
USB HID Peripherals
The PIC18F24K50-I/SO is a near-ideal choice for USB HID-class devices such as custom keyboards, mice, game controllers, and sensor interface dongles because of its integrated USB 2.0 Full-Speed PHY and the free Microchip USB stack. The 16 KB Flash comfortably fits HID report descriptors, scan matrices, and feature firmware, while the 48 MHz CPU handles polling, debouncing, and report encoding in real time without timing jitter. XLP deep-sleep below 100 nA lets battery-powered HID dongles idle for months between wake events, woken by a GPIO interrupt or USB resume. The on-chip 3.3V LDO eliminates the external USB transceiver and regulator, cutting BOM cost by roughly $0.40 per board versus discrete-USB designs.
Recommended
Low-Power Sensor Data Loggers
The PIC18F24K50-I/SO excels in battery-powered data loggers that need USB for charging or data offload. nanoWatt XLP technology drops core current to tens of nanoamps with full RAM retention and RTCC running, so a logger can timestamp readings over months on a single coin cell while periodically waking to sample sensors via the 10-bit ADC. The 14 ADC channels handle thermistors, photocells, and strain gauges simultaneously, and the 256-byte EEPROM provides 100 kcycle-backed scratch storage for calibration constants. USB enumeration provides instant mass-storage or CDC upload when plugged into a host, avoiding the need for an extra serial-to-USB chip.
Recommended
Capacitive Touch User Interfaces
The integrated Charge Time Measurement Unit (CTMU) on the PIC18F24K50-I/SO enables robust capacitive touch sensing across many pads without external touch ICs, making it well suited for appliance front panels, industrial keypads, and consumer-product sliders. Combined with the 10-bit ADC, a single MCU can read 12 to 16 touch pads, drive indicator LEDs via PWM, and communicate over USB to a host controller or over UART to a local master. The 28-SOIC package gives easy hand-solderable or low-cost SMT assembly for medium-volume products. Typical touch firmware runs in under 4 KB, leaving plenty of headroom for USB stacks and bootloader support.
Recommended
USB Charging and Battery Monitors
With its internal 3.3V LDO and 2.3V to 5.5V supply range, the PIC18F24K50-I/SO can be the brain of a USB-charging cradle or smart battery monitor. The ADC monitors cell voltage and current sense, while the USB peripheral advertises charging status to the host and logs charge cycles. XLP low-power modes let the monitor sleep when no battery is connected, drawing under 1 uA from the bus. The part is industrial-grade (-40C to +85C) and handles a wide variety of battery chemistries when paired with the right firmware charge profile.
Recommended
Industrial USB-to-Serial Bridges
The PIC18F24K50-I/SO is widely used in cost-optimized USB-to-UART, USB-to-I2C, and USB-to-SPI bridge products thanks to its integrated USB peripheral, generous Flash for vendor-specific class firmware, and easy access to USART/MSSP. Industrial bridge modules built around this part are common in factory automation, where the MCU appears as a CDC virtual COM port to a host PC or PLC. The 28-SOIC package is durable and reflowable on industrial FR-4 boards. Its wide operating temperature range and nanoWatt XLP idle make it suitable for cabinet-mounted converters with constrained cooling.
Recommended
Consumer Audio/Volume Controllers with USB
The PIC18F24K50-I/SO works well in consumer USB audio accessories such as volume knobs, mute buttons, or HID-CDC combined audio control surfaces. The two PWM modules can drive LED indicators or small haptic feedback, while the ADC reads a rotary encoder or potentiometer for volume. USB HID reports carry the volume changes to the host PC or media player. XLP sleep lets the device enter sub-microamp standby when no audio is active, and the integrated LDO avoids extra power-rail circuitry. The 48 MHz CPU gives enough headroom to debounce encoders and run USB poll loops concurrently without jitter.
Recommended
Recommended Products Summary
Engineering reference data for PIC18F24K50-I/SO — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC18F24K50-E/SO | PIC18F24K50T-I/SO | PIC18F24K40-I/SO | PIC18F24K42-I/SS | PIC18F24K40-E/SO |
|---|---|---|---|---|---|---|
| Package | 28-SOIC (SO) | 28-SOIC (SO) | 28-SOIC (SO) | 28-SOIC (SO) | 28-SSOP (SS) | 28-SOIC (SO) |
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Flash | 16 KB | 16 KB | 16 KB | 20 KB | 16 KB | 20 KB |
| RAM | 2 KB | 2 KB | 2 KB | 2 KB | 2 KB | 2 KB |
| Operating Temperature | -40C to +85C | -40C to +125C | -40C to +85C | -40C to +85C | -40C to +85C | -40C to +125C |
| USB | USB 2.0 FS integrated | USB 2.0 FS integrated | USB 2.0 FS integrated | USB 2.0 FS integrated | USB 2.0 FS integrated | USB 2.0 FS integrated |
| CPU Speed | 48 MHz (16 MIPS) | 48 MHz (16 MIPS) | 48 MHz (16 MIPS) | 48 MHz (16 MIPS) | 48 MHz (16 MIPS) | 48 MHz (16 MIPS) |
| XLP Low-Power | Yes | Yes | Yes | Yes | Yes | Yes |
Key Differentiators
- Integrated USB 2.0 Full-Speed PHY with on-chip 3.3V LDO (vs PIC18F2550-I/SO (legacy predecessor))
- nanoWatt XLP deep-sleep current under 100 nA (vs PIC18F4550-I/P (40-pin sibling))
- Industrial-grade -40C to +85C rating in SOIC package (vs PIC18F24K40-I/SO (same-family newer))
Design Notes
The PIC18F24K50-I/SO includes an internal 3.3V LDO that powers the USB transceiver from a single VDD rail between 2.3V and 5.5V, eliminating an external regulator. When VDD is above 3.3V the USB D+/D- lines still require 27 ohm series resistors, and the VBUS pin must be tied through a divider or directly to VBUS for host detection. For battery-only designs without USB, leave VBUS unconnected and the LDO will be disabled internally.
Place the 0.1 uF VDD decoupling capacitor within 5 mm of pin 20 and a second 1 uF bulk capacitor near the USB connector to handle the dynamic load of USB enumeration transients. The USB D+/D- traces must be routed as a matched pair, 90 ohm differential, and kept under 50 mm; avoid routing them near switching regulators or crystals. Add a 4.7 uF capacitor on the VBUS pin if you want reliable host presence detection on cold plug.
Do not confuse the -I/SO 28-SOIC industrial variant with the -I/SP 28-DIP or -I/ML 28-QFN variants - all three are pin-compatible in pin count but not footprint. CONFIG words must be configured for the correct oscillator mode (HS, XT, INTOSC) before USB stack initialization, otherwise enumeration fails. The MSSP pins on RC3/RC4 share functions with the ICSP debugger, so disable MSSP during debug to avoid contention on PGC/PGD.
Estimated: USB Full-Speed edge rates of 12 Mbps require the D+/D- pair impedance to be 90 ohms differential on a 1.0 mm-thick FR-4 stackup with 0.2 mm trace width; verify with a TDR measurement if cable lengths exceed 50 mm. A common-mode choke on D+/D- is optional but recommended for designs that must survive IEC 61000-4-2 ESD strikes above 8 kV contact discharge.
Compliance Information
RoHS compliant and lead-free per Microchip product page. Industrial-grade -40C to +85C; not AEC-Q100 qualified (use PIC18F24K50-E/SO for higher temp or Q-grade variants for automotive).
