PIC18F4423-E/P - 8-bit 16KB Flash MCU, 40MHz, 40-DIP | Microchip
MPN: PIC18F4423-E/P ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $4.32 | $4.32 |
| 10 | $3.89 | $38.90 |
| 100 | $3.46 | $346.00 |
| 500 | $3.05 | $1,525.00 |
| 1,000 | $2.68 | $2,680.00 |
PIC18F4423-E/P Overview
A PIC18F microcontroller is a Harvard-architecture 8-bit RISC MCU belonging to the wider microcontroller (MCU) family - a category of single-chip computers that integrate CPU, RAM, non-volatile program memory, and peripherals. Within the PIC family hierarchy, PIC18F sits in the enhanced mid-range tier (between PIC16F baseline and dsPIC30/33 DSP families), offering 16-bit instructions, 31-level stack, and C-friendly architecture. PIC18F MCUs are widely used in industrial control, automotive body electronics, and consumer products where deterministic real-time performance and 5 V tolerance are required.
Key features of the PIC18F4423-E/P include 16 KB Flash program memory, 768 bytes of RAM, 256 bytes of EEPROM, 25 mA source/sink per I/O, four timer modules (Timer0/1/2/3), a 10-bit ADC with 13 input channels, and two enhanced capture/compare/PWM (ECCP) modules. The device supports ICSP (In-Circuit Serial Programming) and ICD (In-Circuit Debugging) via the MPLAB ecosystem.
The PIC18F4423-E/P's 40-pin PDIP footprint and 5 V tolerance make it a direct successor to legacy PIC16F and early PIC18F designs. It is widely deployed where hand-solderable through-hole assembly and robust 5 V I/O are required - notably industrial automation modules, HVAC controllers, motor control boards, and instrumentation front-ends.
When designing with this part, place a 100 nF decoupling capacitor within 5 mm of each VDD/VSS pin pair, and add a 10 uF bulk capacitor on the main supply rail. The MCLR reset pin requires a 10 kohm pull-up to VDD; the device can be programmed/debugged in-circuit via the ICSPDAT/ICSPCLK pins using the MPLAB PICkit 5.
Drop-in alternatives for PIC18F4423-E/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-E/P (same form factor and footprint) — differing in Package, I/O Pins, Maximum CPU Speed, Timers, Operating Temperature.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PIC18F4423-I/P
✅ Drop-In✓ In Stock
$4.05 / Unit
View Datasheet →PIC18F4423-E/P Maximum Ratings & Electrical Characteristics
| Core Architecture | 8-bit PIC18 enhanced RISC (Harvard) |
| Program Memory (Flash) | 16 KB |
| RAM | 768 bytes |
| EEPROM | 256 bytes |
| Maximum CPU Speed | 40 MHz (10 MIPS) |
| Supply Voltage (VDD) | 4.2 V to 5.5 V |
| I/O Pins | 36 |
| ADC | 10-bit, up to 13 channels |
| Comparators | 2 analog comparators |
| Timers | 4 (Timer0, Timer1, Timer2, Timer3) |
| ECCP/PWM Modules | 2 |
| Communication | 1x USART (RS-232/RS-485), 1x MSSP (SPI/I2C) |
| Operating Temperature | -40 C to +125 C (Extended, -E suffix) |
| Package | 40-pin PDIP (DIP-40, 0.600 inch) |
| Mounting Type | Through-Hole |
| ICSP/ICD | Yes (In-Circuit Serial Programming / Debug) |
| Power-Saving Modes | nanoWatt (Sleep, Idle, etc.) |
| Lead-Free / RoHS | Lead-Free finish (RoHS compliant per Microchip product page) |
PIC18F4423-E/P Pin Configuration
| Pin 1 | MCLR/RE3 — Master Clear (reset) input / digital input only on RE3 |
| Pin 2 | RA0/AN0 — Digital I/O / analog input AN0 |
| Pin 3 | RA1/AN1 — Digital I/O / analog input AN1 |
| Pin 4 | RA2/AN2/VREF- — Digital I/O / analog input AN2 / ADC VREF- |
| Pin 5 | RA3/AN3/VREF+ — Digital I/O / analog input AN3 / ADC VREF+ |
| Pin 6 | RA4/T0CKI — Digital I/O / Timer0 clock input |
| Pin 7 | RA5/AN4/SS — Digital I/O / analog input AN4 / SPI slave select |
| Pin 8 | RE0/RD/AN5 — Digital I/O / parallel-port read / AN5 |
| Pin 9 | RE1/WR/AN6 — Digital I/O / parallel-port write / AN6 |
| Pin 10 | RE2/CS/AN7 — Digital I/O / parallel-port chip select / AN7 |
| Pin 11 | VDD — Positive supply voltage (4.2 V to 5.5 V) |
| Pin 12 | VSS — Ground reference |
| Pin 13 | OSC1/CLKI/RA7 — Crystal oscillator input / external clock input / digital I/O |
| Pin 14 | OSC2/CLKO/RA6 — Crystal oscillator output / clock output / digital I/O |
| Pin 15 | RC0/T1OSO/T1CKI — Digital I/O / Timer1 oscillator output / Timer1 clock input |
| Pin 16 | RC1/T1OSI/CCP2 — Digital I/O / Timer1 oscillator input / CCP2 PWM output |
| Pin 17 | RC2/CCP1 — Digital I/O / CCP1 PWM output |
| Pin 18 | RC3/SCK/SCL — Digital I/O / MSSP SPI clock / I2C clock |
| Pin 19 | RD0/PSP0 — Digital I/O / parallel slave port data bit 0 |
| Pin 20 | RD1/PSP1 — Digital I/O / parallel slave port data bit 1 |
| Pin 21 | RD2/PSP2 — Digital I/O / parallel slave port data bit 2 |
| Pin 22 | RD3/PSP3 — Digital I/O / parallel slave port data bit 3 |
| Pin 23 | RC4/SDI/SDA — Digital I/O / MSSP SPI data in / I2C data |
| Pin 24 | RC5/SDO — Digital I/O / MSSP SPI data out |
| Pin 25 | RC6/TX/CK — Digital I/O / USART asynchronous transmit / clock |
| Pin 26 | RC7/RX/DT — Digital I/O / USART asynchronous receive / data |
| Pin 27 | RD4/PSP4 — Digital I/O / parallel slave port data bit 4 |
| Pin 28 | RD5/PSP5 — Digital I/O / parallel slave port data bit 5 |
| Pin 29 | RD6/PSP6 — Digital I/O / parallel slave port data bit 6 |
| Pin 30 | RD7/PSP7 — Digital I/O / parallel slave port data bit 7 |
| Pin 31 | VSS — Ground reference |
| Pin 32 | VDD — Positive supply voltage (4.2 V to 5.5 V) |
| Pin 33 | RB0/INT0/FLT0 — Digital I/O / external interrupt 0 / ECCP fault input |
| Pin 34 | RB1/INT1 — Digital I/O / external interrupt 1 |
| Pin 35 | RB2/INT2 — Digital I/O / external interrupt 2 |
| Pin 36 | RB3/CCP2A — Digital I/O / alternate CCP2 output |
| Pin 37 | RB4 — Digital I/O with interrupt-on-change |
| Pin 38 | RB5 — Digital I/O with interrupt-on-change |
| Pin 39 | RB6/PGC/ICSPCLK — Digital I/O / ICSP clock / ICD clock |
| Pin 40 | RB7/PGD/ICSPDAT — Digital I/O / ICSP data / ICD data |
Typical Applications
PIC18F4423-E/P is suitable for 6 applications: Industrial PLC I/O Modules, HVAC Thermostat Controllers, Brushless DC Motor Control, Automotive Body Electronics, Instrumentation and Data Loggers, Consumer Appliance Control Boards.
Industrial PLC I/O Modules
The PIC18F4423-E/P fits industrial PLC I/O modules because its 5 V I/O tolerance and -40 C to +125 C extended temperature grade allow direct interfacing to 24 V optically-isolated digital inputs and relay outputs without level shifters. The 13-channel 10-bit ADC reads analog sensor inputs (4-20 mA transducers scaled through sense resistors, NTC thermistors, potentiometers), while the two ECCP/PWM modules drive indicator LEDs, buzzer tones, or solid-state relay triggers. The 40-pin PDIP through-hole package simplifies hand-assembly and field-serviceable maintenance in DIN-rail cabinets.
Recommended
HVAC Thermostat Controllers
The PIC18F4423-E/P is well-suited to HVAC thermostat controllers because its nanoWatt sleep modes (sub-microampere standby) extend battery life in wireless thermostats, while the 36 I/O pins drive LCD segments, push-button keypads, relay outputs, and triac optocouplers for furnace/AC control. The 10-bit ADC reads onboard thermistors (10K NTC type II/III) with adequate resolution for +/- 0.5 C temperature accuracy after linearization, and the USART interfaces to Wi-Fi/BLE modules for smart-thermostat networking. Extended temperature tolerance handles plenum-mounted installations.
Recommended
Brushless DC Motor Control
The PIC18F4423-E/P drives small brushless DC (BLDC) and brushed DC motors because its two ECCP/PWM modules generate complementary 3-phase PWM at up to 40 MHz with hardware dead-band control, while the 13-channel 10-bit ADC samples back-EMF zero-crossings, current sense, and potentiometer speed reference. The USART provides a debug/command port, and the MSSP drives SPI encoders for closed-loop position control. With 16 KB Flash, sensorless or sensored BLDC firmware fits comfortably with room for adaptive commutation and fault-handling routines.
Recommended
Automotive Body Electronics
The PIC18F4423-E/P serves body-electronics applications such as instrument cluster sub-modules, lighting controllers, seat controllers, and HVAC blend-door actuators because its -40 C to +125 C extended temperature grade and 5 V rail operation match automotive 12 V battery-direct systems after regulation. The 36 I/O pins drive LED drivers, button matrices, and LIN/CAN-friendly transceivers (USART to external LIN phy), while the ECCP modules generate PWM for LED dimming and small motor speed control. NanoWatt sleep drops quiescent to <1 uA to meet <100 uA parasitic-draw budgets on parked vehicles.
Recommended
Instrumentation and Data Loggers
The PIC18F4423-E/P is widely used in portable instrumentation and data loggers because its 10-bit 13-channel ADC scans multiple sensor inputs (temperature, pressure, voltage, current) at up to ~100 ksps aggregate, and 768 bytes of RAM plus 256 bytes EEPROM buffer and store calibration constants between power cycles. The USART outputs ASCII or Modbus frames to host PCs, while the MSSP interfaces to SPI Flash or EEPROM for mass-storage of logged samples. Extended temperature grade handles outdoor and industrial cabinet environments where loggers are deployed.
Recommended
Consumer Appliance Control Boards
The PIC18F4423-E/P is found in washing machines, dishwashers, microwave ovens, and small kitchen appliances because its 5 V tolerance interfaces directly to triac optocouplers, mechanical relays, and 7-segment LED displays without external level translation. The 16 KB Flash stores user-interface state machines and safety routines, while the ECCP modules drive triac phase-control or PWM for variable-speed pumps and fans. The through-hole 40-pin PDIP allows wave-solder assembly at lower cost than QFP packages for high-volume appliance manufacturing.
Recommended
Recommended Products Summary
Engineering reference data for PIC18F4423-E/P — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC18F4423-I/P | PIC18F4420-E/P | PIC18F4320-E/P | PIC18F4520-E/P |
|---|---|---|---|---|---|
| Package | 40-pin PDIP (DIP-40) | 40-pin PDIP (DIP-40) - same | 40-pin PDIP (DIP-40) - same | 40-pin PDIP (DIP-40) - same | 40-pin PDIP (DIP-40) - same |
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Program Flash | 16 KB | 16 KB - same | 8 KB (-50%) | 8 KB (-50%) | 32 KB (+100%) |
| RAM | 768 bytes | 768 bytes - same | 256 bytes (-67%) | 512 bytes (-33%) | 1536 bytes (+100%) |
| EEPROM | 256 bytes | 256 bytes - same | 256 bytes - same | 256 bytes - same | 256 bytes - same |
| Max CPU Speed | 40 MHz / 10 MIPS | 40 MHz / 10 MIPS - same | 40 MHz / 10 MIPS - same | 40 MHz / 10 MIPS - same | 40 MHz / 10 MIPS - same |
| Supply Voltage | 4.2 V to 5.5 V | 4.2 V to 5.5 V - same | 4.2 V to 5.5 V - same | 4.2 V to 5.5 V - same | 4.2 V to 5.5 V - same |
| Operating Temperature | -40 C to +125 C (Extended) | -40 C to +85 C (Industrial) | -40 C to +125 C (Extended) | -40 C to +125 C (Extended) | -40 C to +125 C (Extended) |
| ADC | 10-bit, 13 channels | 10-bit, 13 channels - same | 10-bit, 13 channels - same | 10-bit, 13 channels - same | 10-bit, 13 channels - same |
| I/O Pins | 36 | 36 - same | 36 - same | 36 - same | 36 - same |
Key Differentiators
- Highest Flash/RAM in 40-pin PDIP PIC18F4x20 family (vs PIC18F4420-E/P)
- Extended temperature grade for automotive/harsh-environment designs (vs PIC18F4423-I/P)
- Larger RAM and Flash than PIC18F4320-E/P for richer firmware (vs PIC18F4320-E/P)
Design Notes
Place a 100 nF ceramic decoupling capacitor within 5 mm of every VDD/VSS pin pair (the PIC18F4423-E/P has two pairs: pins 11/12 and pins 31/32). Add a 10 uF bulk electrolytic or tantalum capacitor on the main 5 V rail near the MCU. If the supply is sourced from a switching regulator (e.g., 24 V to 5 V buck), add a ferrite bead or LC filter to attenuate switching ripple below 50 mVpp - the MCU is sensitive to VDD noise because the ADC reference is derived from VDD unless an external VREF+ is used. Estimated total decoupling budget: ~12 nF of ceramic plus 10 uF bulk is sufficient for 40 MHz operation.
The MCLR reset pin (pin 1) requires a 10 kohm pull-up resistor to VDD; some designs add a 100 nF capacitor from MCLR to VSS for hardware debounce of noisy power-on transients. The ICSPDAT (pin 40) and ICSPCLK (pin 39) pins double as RB7 and RB6 - keep the MPLAB ICSP header footprint on the PCB even if not populated in production, so future firmware updates and ICD debugging can be performed without rework. Keep crystal traces short and surrounded by a ground guard ring; place the load capacitors (typically 22-33 pF for HS mode at 20 MHz) within 5 mm of OSC1/OSC2.
Do not omit the 100 nF bypass on AVDD/VSS if you reference the ADC from VDD - noise on the supply rail couples directly into ADC readings. Do not drive the MCLR pin with an open-collector driver without the pull-up - the device will not exit reset reliably. When using the internal oscillator, calibrate the frequency via the OSCTUNE register; uncalibrated parts can vary by +/- 2% across temperature, which causes UART baud-rate errors above 9600 baud at +85 C. Finally, do not exceed 25 mA source or sink per I/O pin or 200 mA total VDD/VSS current - exceeding this damages the device.
Compliance Information
Lead-free finish per Microchip product page; RoHS and REACH compliant. AEC-Q100 not formally qualified (extended temperature grade -E is intended for industrial / harsh-environment use, not full automotive qualification).
