PIC18F4423-I/P - 8-Bit 40MHz 16KB Flash MCU 40-PDIP | Microchip
MPN: PIC18F4423-I/P ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $6.68 | $6.68 |
| 10 | $5.91 | $59.10 |
| 100 | $5.04 | $504.00 |
| 500 | $4.45 | $2,225.00 |
| 1,000 | $4.05 | $4,050.00 |
PIC18F4423-I/P Overview
An 8-bit microcontroller (MCU) is a single-chip computer that integrates a CPU, program memory (Flash), data memory (RAM), and peripherals onto one die. The PIC18 family employs an 8-bit data path with a RISC instruction set, an enhanced Harvard architecture with separate program and data buses, and a 31-level hardware stack. Within the broader IC hierarchy, the PIC18F4423 belongs to the microcontroller category, sitting beneath 16-bit and 32-bit MCUs in processing capability while outperforming baseline PIC10/PIC12/PIC16 parts in peripherals and memory.
Key features include a 10-bit Analog-to-Digital Converter (ADC) with up to 13 channels, two analog comparators, a Capture/Compare/PWM (CCP) module, an Enhanced Universal Synchronous/Asynchronous Receiver Transmitter (EUSART), a Master Synchronous Serial Port (MSSP) supporting SPI and I2C, and nanoWatt power-management technology that drops quiescent current into the sub-microamp range for sleep-mode battery applications. The 36 programmable I/O pins are 5V-tolerant and source/sink up to 25 mA per pin, sufficient to drive LEDs and small relays directly.
The PIC18F4423 uses Microchip's enhanced flash cell with self-programmability under application control, supporting in-circuit serial programming (ICSP) and a robust code-protection scheme. Internal oscillator options and a programmable brown-out reset (BOR) reduce external component count, while a hardware Watchdog Timer with postscaler adds fail-safe operation in unattended systems.
Typical applications include industrial sensor acquisition boards, HVAC fan/thermostat control, low-end human-interface panels, appliance controllers, and battery-powered metering modules that benefit from nanoWatt sleep modes. Hobbyist and educational platforms also use the PIC18F4423 as a gateway into the PIC ecosystem because of its abundant tutorials and free MPLAB X IDE toolchain.
When designing with the PIC18F4423, ensure that VDD decoupling (0.1 uF ceramic close to each VDD/VDD-Pin pair) and a 10 kohm pull-up on MCLR are placed per Microchip's analog-layout guidelines. The 40-pin PDIP footprint offers generous board real estate for hand-soldered prototypes and breadboard-friendly development, but migrated designs should select the TQFP-44 surface-mount package variants for volume production.
This page synthesizes distributor pricing, same-family drop-in alternatives, and practical design notes that are not aggregated on a single manufacturer or distributor page.
Drop-in alternatives for PIC18F4423-I/P — 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 PIC18F4423-I/P (same form factor and footprint) — differing in Package, Operating Temperature, Timers, Communication, Program Memory (Flash).
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PIC18F4423-E/P
✅ Drop-In✓ In Stock
$2.68 / Unit
View Datasheet →PIC18F4420-I/P
✅ Drop-In📋 Reference alternative (not in catalog)
PIC18F4320-I/P
✅ Drop-In✓ In Stock
$4.05 / Unit
View Datasheet →PIC18F4523-I/P
✅ Drop-In✓ In Stock
$2.82 / Unit
View Datasheet →PIC18F43K20-I/P
✅ Drop-In✓ In Stock
$1.95 / Unit
View Datasheet →PIC18F4410-I/P
✅ Drop-In✓ In Stock
$4.7 / Unit
View Datasheet →PIC18F4220-I/P
✅ Drop-In✓ In Stock
$4.78 / Unit
View Datasheet →PIC18F43K22-I/PT
✅ Drop-In✓ In Stock
$1.95 / Unit
View Datasheet →PIC18F4423-I/P Maximum Ratings & Electrical Characteristics
| Family | PIC18F |
| Core | 8-bit PIC RISC |
| Program Memory | 16 KB Flash |
| RAM | 768 bytes |
| EEPROM | 256 bytes |
| Maximum CPU Speed | 40 MHz (16 MIPS) |
| Supply Voltage (Vdd) | 2.0 V to 5.5 V |
| Operating Temperature Range | -40 C to +85 C (Industrial, "-I" grade) |
| I/O Pins | 36 |
| ADC | 10-bit, up to 13 channels |
| Comparators | 2 analog comparators |
| Communication Interfaces | 1x EUSART (UART), 1x MSSP (SPI / I2C) |
| CCP Modules | 2 (Capture / Compare / PWM) |
| Timers | Timer0 (8-bit), Timer1 (16-bit), Timer2 (8-bit), Timer3 (16-bit) |
| Package | 40-pin PDIP (DIP-40, 0.600 in) |
| Mounting Type | Through-Hole |
| Power-Saving Modes | nanoWatt Technology (Idle, Sleep, Deep Sleep) |
| In-Circuit Programming | ICSP via PGC/PGD and MCLR |
| MSL Level | Not Applicable (Through-Hole PDIP) |
PIC18F4423-I/P Pin Configuration
| Pin 1 | MCLR/RE3/VPP — Master Clear (reset) input / digital input pin RE3 / programming voltage |
| Pin 2 | RA0/AN0 — Port A bit 0 / analog input channel 0 |
| Pin 3 | RA1/AN1 — Port A bit 1 / analog input channel 1 |
| Pin 4 | RA2/AN2/VREF- — Port A bit 2 / analog input ch.2 / ADC Vref- |
| Pin 5 | RA3/AN3/VREF+ — Port A bit 3 / analog input ch.3 / ADC Vref+ |
| Pin 6 | RA4/T0CKI — Port A bit 4 / Timer0 clock input |
| Pin 7 | RA5/AN4 — Port A bit 5 / analog input channel 4 |
| Pin 8 | VSS — Ground |
| Pin 9 | OSC1/CLKI/RA7 — External oscillator input / Port A bit 7 |
| Pin 10 | OSC2/CLKO/RA6 — External oscillator output / Port A bit 6 |
| Pin 11 | RC0/T1OSO — Port C bit 0 / Timer1 oscillator output |
| Pin 12 | RC1/T1OSI — Port C bit 1 / Timer1 oscillator input |
| Pin 13 | RC2/CCP1 — Port C bit 2 / Capture-Compare-PWM 1 |
| Pin 14 | RC3/SCL/SCK — Port C bit 3 / I2C clock / SPI clock |
| Pin 15 | RC4/SDA/SDI — Port C bit 4 / I2C data / SPI data in |
| Pin 16 | RC5/SDO — Port C bit 5 / SPI data out |
| Pin 17 | RC6/TX/CK — Port C bit 6 / EUSART TX / clock |
| Pin 18 | RC7/RX/DT — Port C bit 7 / EUSART RX / data |
| Pin 19 | VSS — Ground |
| Pin 20 | VDD — Positive supply |
| Pin 21 | RB0/INT0 — Port B bit 0 / external interrupt 0 |
| Pin 22 | RB1/INT1 — Port B bit 1 / external interrupt 1 |
| Pin 23 | RB2/INT2 — Port B bit 2 / external interrupt 2 |
| Pin 24 | RB3/CCP2 — Port B bit 3 / CCP2 |
| Pin 25 | RB4 — Port B bit 4 |
| Pin 26 | RB5 — Port B bit 5 |
| Pin 27 | RB6/PGC — Port B bit 6 / ICSP clock |
| Pin 28 | RB7/PGD — Port B bit 7 / ICSP data |
| Pin 29 | VSS — Ground |
| Pin 30 | VDD — Positive supply |
| Pin 31 | VSS — Ground |
| Pin 32 | VDD — Positive supply |
| Pin 33 | RD0/PSP0 — Port D bit 0 / Parallel Slave Port bit 0 |
| Pin 34 | RD1/PSP1 — Port D bit 1 / PSP bit 1 |
| Pin 35 | RD2/PSP2 — Port D bit 2 / PSP bit 2 |
| Pin 36 | RD3/PSP3 — Port D bit 3 / PSP bit 3 |
| Pin 37 | RD4/PSP4 — Port D bit 4 / PSP bit 4 |
| Pin 38 | RD5/PSP5 — Port D bit 5 / PSP bit 5 |
| Pin 39 | RD6/PSP6 — Port D bit 6 / PSP bit 6 |
| Pin 40 | RD7/PSP7 — Port D bit 7 / PSP bit 7 |
Typical Applications
PIC18F4423-I/P is suitable for 7 applications: Industrial Sensor Acquisition Board, HVAC Fan and Thermostat Controller, Low-End Human-Machine Interface Panel, Appliance Controller (Washers, Ovens, Dishwashers), Battery-Powered Metering Module, Educational and Hobbyist Embedded Platform, Automotive Interior Auxiliary Controller.
Industrial Sensor Acquisition Board
The PIC18F4423-I/P is well suited for industrial multi-sensor data acquisition boards thanks to its 10-bit ADC with up to 13 input channels and 36 programmable I/O pins that can read thermocouples, strain gauges and 4-20 mA loop circuits. The 40 MHz / 16 MIPS throughput delivers real-time averaging, linearization and digital filtering for noisy industrial environments, while the wide 2.0V-5.5V supply range tolerates unstable 24V-derived rails. Sleep-mode nanoWatt Technology drops quiescent current below 1 uA in battery-backed installations, and the 256-byte EEPROM stores calibration constants across decades without corruption.
Recommended
HVAC Fan and Thermostat Controller
The PIC18F4423-I/P's two CCP modules can drive triac-fired blower motors and PWM-controlled damper actuators, while the 10-bit ADC reads NTC thermistors and humidity sensors with adequate resolution for setpoint control. Industrial -40C to +85C temperature rating covers unconditioned HVAC closets, and the 40-pin PDIP package simplifies hand-rework in service-channel boards. nanoWatt Sleep keeps the panel idle between button presses, supporting seasonal efficiency goals.
Recommended
Low-End Human-Machine Interface Panel
For low-end HMI panels with rotary encoders, pushbuttons, character LCDs and small LED arrays, the PIC18F4423-I/P provides 36 I/Os capable of sourcing/sinking 25 mA per pin (sufficient for direct LED drive). The MSSP port drives SPI LCD or I2C I/O expanders, while EUSART handles Modbus RTU master to upstream PLCs. Industrial temperature grade allows panels on factory floors without conformal coating.
Recommended
Appliance Controller (Washers, Ovens, Dishwashers)
The PIC18F4423-I/P fits mid-volume white-goods controllers because its 16 KB Flash covers typical IEC 60730 safety-software libraries while the MSSP/EUSART ports drive triac modules and user-interfaces. nanoWatt sleep helps meet standby <0.5 W energy rules in the EU and North America. The 40-pin PDIP supports legacy through-hole board layouts commonly used in Asian appliance OEM factories.
Recommended
Battery-Powered Metering Module
The PIC18F4423-I/P's nanoWatt Technology makes it viable for battery-powered metering modules drawing <1 uA in sleep, waking periodically to measure flow, gas pulses or temperature. The 256-byte EEPROM stores 36+ months of interval logs, and the 10-bit ADC digitizes pulse-conditioning amplifier outputs. Industrial temperature grade tolerates outdoor meter housings.
Recommended
Educational and Hobbyist Embedded Platform
The PIC18F4423-I/P is widely used in university embedded courses and hobbyist makers because of its breadboard-friendly 40-pin PDIP footprint, ample Flash for student projects, and the free MPLAB X IDE + XC8 toolchain. Documented external interrupt, ADC and PWM peripherals give beginners measurable outcomes in lab, and the PICkit 3/4 programmer plugs directly into the ICSP pins.
Recommended
Automotive Interior Auxiliary Controller
Although not AEC-Q100 qualified, the PIC18F4423-I/P is used in low-stress interior automotive modules (LED mood lighting, vanity mirror control, HVAC blend-door actuators) within cab temperature environments that fall inside its -40C to +85C rating. EUSART enables LIN-bus slave emulation and the 10-bit ADC reads interior temperature sensors; 36 I/Os multiplex LED drivers and rotary inputs.
Recommended
Recommended Products Summary
Engineering reference data for PIC18F4423-I/P — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC18F4423-E/P | PIC18F4420-I/P | PIC18F4523-I/P | PIC18F43K20-I/P |
|---|---|---|---|---|---|
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Package | 40-pin PDIP (0.600 in) | 40-pin PDIP (0.600 in) - same | 40-pin PDIP (0.600 in) - same | 40-pin PDIP (0.600 in) - same | 40-pin PDIP (0.600 in) - same |
| Program Memory (Flash) | 16 KB | 16 KB | 16 KB | 48 KB | 8 KB |
| RAM | 768 bytes | 768 bytes | 768 bytes | 1.5 KB | 512 bytes |
| Max CPU Speed | 40 MHz (16 MIPS) | 40 MHz | 40 MHz | 40 MHz | 64 MHz (16 MIPS) |
| Supply Voltage Range | 2.0 V to 5.5 V | 2.0 V to 5.5 V | 2.0 V to 5.5 V | 2.0 V to 5.5 V | 1.8 V to 5.5 V |
| Operating Temperature | -40 C to +85 C | -40 C to +125 C | -40 C to +85 C | -40 C to +85 C | -40 C to +85 C |
| I/O Pins | 36 | 36 | 36 | 36 | 36 |
| ADC | 10-bit, 13 channels | 10-bit, 13 channels | 10-bit, 13 channels | 10-bit, 13 channels | 10-bit, 14 channels |
Key Differentiators
- Broader ADC channel count than K-series pin-compatible upgrade (vs PIC18F43K20-I/P)
- Three times the Flash headroom at similar cost to PIC18F4320-I/P (vs PIC18F4320-I/P)
- Industrial temperature grade with future upgrade path to automotive (vs PIC18F4423-E/P)
Design Notes
Place a 0.1 uF ceramic decoupling capacitor close to each VDD pin (pins 11, 32) and a 10 uF bulk electrolytic/ceramic at the regulator output. The PIC18F4423-I/P shares two VSS pins (8 and 19) and two VDD pins; both must be properly decoupled to avoid AVDD/VSS droop during ADC conversions. This is documented in Section 2.0 (Power Management) of the Microchip datasheet and is a critical recommendation for ADC accuracy.
Keep analog input traces (RA0-RA5) short and away from the high-speed digital lines such as the EUSART TX/RX (RC6/RC7) or PWM outputs (RC2/CCP1). On the 40-pin PDIP layout there is generous room for a ground-pour adjacent to the analog portion to keep ADC noise under 1 LSB at 10-bit resolution with a moderate-bandwidth op-amp front-end.
MCLR (pin 1) must be pulled up to VDD through a 10 kohm resistor and have a 100 nF cap to VSS; without the cap, ESD transients can falsely reset the MCU in industrial environments. Configuration word bit MCLRE must be programmed to '1' to enable the external MCLR function, otherwise the reset function defaults to an internal weak pull-up and the pin behaves differently from the datasheet timing expectations.
Pin 9 (OSC1) and pin 10 (OSC2) traces should be routed first as a matched-length pair with the oscillator (or crystal) within a few millimeters of the MCU. Avoid running switching signals across these traces to prevent EMI from injecting jitter into the system clock; this matters more at 40 MHz than at lower oscillator modes.
ICSP signals on pins 27/28 (PGC/PGD) should be kept away from the analog inputs, ideally with a guard-ground trace. When laying out a board that uses both ICSP programming and AC line-driven peripherals (triac / optoisolator), retain a low-impedance ground return path so that programmer-induced ground bounce does not couple into the ADC reference.
Compliance Information
RoHS and lead-free per Microchip product page; not AEC-Q100 - use automotive-grade K-series for vehicular applications. Halogen-free status not confirmed in the provided data.
