PIC18F4320-E/P - 8KB Flash 8-bit MCU, 40MHz, DIP-40 | Microchip
MPN: PIC18F4320-E/P ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $4.5 | $4.50 |
| 10 | $4.05 | $40.50 |
| 100 | $3.6 | $360.00 |
| 500 | $3.24 | $1,620.00 |
| 1,000 | $2.95 | $2,950.00 |
PIC18F4320-E/P Overview
An 8-bit microcontroller (MCU) is a small computer-on-a-chip containing a CPU, RAM, non-volatile program memory, and peripherals. PIC18F microcontrollers belong to the enhanced mid-range PIC architecture, sitting between baseline PIC10/12/16 devices and PIC24/dsPIC 16-bit families. They execute one instruction per clock cycle, providing deterministic performance for embedded control. PIC18F4320-E/P fits this hierarchy as a general-purpose 8-bit MCU with nanoWatt power management.
Key features include 36 digital I/O pins, 13 channels of 10-bit Analog-to-Digital conversion (10-bit ADC), two analog comparators, two Capture/Compare/PWM modules, and a synchronous serial port configurable as 3-wire SPI or 2-wire I2C. The device supports self-programming and In-Circuit Debugging (ICD) via two programming pins. nanoWatt Technology provides multiple power-managed modes - Run, Idle, and Sleep - with on-the-fly clock switching from a 31 kHz internal oscillator up to 40 MHz external.
The architecture uses a Harvard bus with separate program and data paths, an 8-bit ALU, and a 16-bit instruction word. Four interrupt priority levels and a hardware multiplier (8x8 single-cycle) simplify real-time control loops. The 10-bit ADC supports 13 input channels with acquisition time configurable for precision conversion. Two USART modules plus the MSSP (Master Synchronous Serial Port) provide flexible wired communication.
Typical applications include industrial control systems, automotive body electronics, sensor signal conditioning, motor control loops, HVAC thermostats, and consumer appliance interfaces. The 5V supply range and extended temperature grade also suit outdoor and factory-floor equipment.
When designing, allocate the ICD pins (PGC/PGD) carefully - they must remain accessible for debug, and the MCLR pin needs a 10 kohm pull-up to VDD. The 40-pin PDIP footprint provides through-hole mechanical robustness for hand-prototyped and field-serviceable boards.
This page synthesizes distributor pricing, drop-in alternatives, and practical design notes not aggregated on the manufacturer product page or in the standalone datasheet.
Drop-in alternatives for PIC18F4320-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 PIC18F4320-E/P (same form factor and footprint) — differing in Package, Maximum CPU Speed, Program Memory (Flash), Core, MSL Level.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PIC18F4320-I/P
✅ Drop-In✓ In Stock
$4.05 / Unit
View Datasheet →PIC18F4220-E/P
✅ Drop-In✓ In Stock
$4.65 / Unit
View Datasheet →PIC18F4321-E/P
✅ Drop-In✓ In Stock
$3.61 / Unit
View Datasheet →PIC18F4331-E/P
✅ Drop-In✓ In Stock
$4.21 / Unit
View Datasheet →PIC18F4431-E/P
✅ Drop-In✓ In Stock
$3.85 / Unit
View Datasheet →PIC18F4320-E/P Maximum Ratings & Electrical Characteristics
| Core Architecture | PIC18 (8-bit RISC, Harvard bus) |
| Program Memory (Flash) | 8 KB (4K x 16 words) |
| Data SRAM | 512 bytes |
| Data EEPROM | 256 bytes |
| Maximum Clock Speed | 40 MHz |
| Performance | 10 MIPS |
| Supply Voltage (VDD) | 4.2 V to 5.5 V |
| Digital I/O Pins | 36 |
| ADC | 10-bit, 13 channels |
| Analog Comparators | 2 |
| Capture/Compare/PWM Modules | 2 |
| Serial Interfaces | MSSP (SPI / I2C), 2x USART (AUSART) |
| Operating Temperature (E suffix) | -40C to +125C |
| Package | PDIP-40 (DIP-40, 0.600 in / 15.24 mm) |
| Mounting Type | Through-Hole |
| RoHS Status | Compliant |
| Power-Saving Modes | nanoWatt (Run / Idle / Sleep) |
PIC18F4320-E/P Pin Configuration
| Pin 1 | MCLR — Master Clear (reset) input, internal pull-up enabled by configuration |
| Pin 2 | RA0/AN0 — PORTA bit 0 / Analog input channel 0 |
| Pin 3 | RA1/AN1 — PORTA bit 1 / Analog input channel 1 |
| Pin 4 | RA2/AN2/VREF- — PORTA bit 2 / Analog input channel 2 / ADC VREF- |
| Pin 5 | RA3/AN3/VREF+ — PORTA bit 3 / Analog input channel 3 / ADC VREF+ |
| Pin 6 | RA4/T0CKI — PORTA bit 4 / Timer0 clock input |
| Pin 7 | RA5/AN4/SS — PORTA bit 5 / Analog input channel 4 / SPI slave select |
| Pin 8 | OSC1/CLKI — Crystal oscillator input / external clock input |
| Pin 9 | OSC2/CLKO — Crystal oscillator output / clock output (Fosc/4) |
| Pin 10 | RC0/T1OSO/T1CKI — PORTC bit 0 / Timer1 oscillator output / Timer1 clock input |
| Pin 11 | RC1/T1OSI/CCP2 — PORTC bit 1 / Timer1 oscillator input / CCP2 PWM output |
| Pin 12 | RC2/CCP1 — PORTC bit 2 / CCP1 PWM output |
| Pin 13 | RC3/SCK/SCL — PORTC bit 3 / SPI clock / I2C clock (MSSP) |
| Pin 14 | RC4/SDI/SDA — PORTC bit 4 / SPI data in / I2C data (MSSP) |
| Pin 15 | RC5/SDO — PORTC bit 5 / SPI data out (MSSP) |
| Pin 16 | RC6/TX/CK — PORTC bit 6 / AUSART TX / clock |
| Pin 17 | RC7/RX/DT — PORTC bit 7 / AUSART RX / data |
| Pin 18 | RD0/PSP0 — PORTD bit 0 / Parallel Slave Port bit 0 |
| Pin 19 | RD1/PSP1 — PORTD bit 1 / Parallel Slave Port bit 1 |
| Pin 20 | RD2/PSP2 — PORTD bit 2 / Parallel Slave Port bit 2 |
| Pin 21 | RD3/PSP3 — PORTD bit 3 / Parallel Slave Port bit 3 |
| Pin 22 | RD4/PSP4 — PORTD bit 4 / Parallel Slave Port bit 4 |
| Pin 23 | RD5/PSP5 — PORTD bit 5 / Parallel Slave Port bit 5 |
| Pin 24 | RD6/PSP6 — PORTD bit 6 / Parallel Slave Port bit 6 |
| Pin 25 | RD7/PSP7 — PORTD bit 7 / Parallel Slave Port bit 7 |
| Pin 26 | VSS — Ground reference |
| Pin 27 | VDD — Positive supply voltage (4.2 V to 5.5 V) |
| Pin 28 | RB0/INT0/FLT0 — PORTB bit 0 / External interrupt 0 / PWM fault input |
| Pin 29 | RB1/INT1 — PORTB bit 1 / External interrupt 1 |
| Pin 30 | RB2/INT2 — PORTB bit 2 / External interrupt 2 |
| Pin 31 | RB3/CCP2 — PORTB bit 3 / CCP2 PWM output (alternate) |
| Pin 32 | RB4 — PORTB bit 4 (interrupt-on-change) |
| Pin 33 | RB5/PGM — PORTB bit 5 / Low-voltage ICSP programming |
| Pin 34 | RB6/PGC — PORTB bit 6 / ICD clock (PGC) |
| Pin 35 | RB7/PGD — PORTB bit 7 / ICD data (PGD) |
| Pin 36 | RE0/RD/AN5 — PORTE bit 0 / Read control / Analog input 5 |
| Pin 37 | RE1/WR/AN6 — PORTE bit 1 / Write control / Analog input 6 |
| Pin 38 | RE2/CS/AN7 — PORTE bit 2 / Chip select / Analog input 7 |
| Pin 39 | AVDD — Analog supply voltage (tie to VDD) |
| Pin 40 | AVSS — Analog ground (tie to VSS) |
Typical Applications
PIC18F4320-E/P is suitable for 7 applications: Industrial Control and Sensor Signal Conditioning, Automotive Body Electronics and HVAC, Consumer Appliance Control Boards, HVAC Thermostats and Building Automation, Motor Control and PWM Driver Stages, Educational and Development Prototyping Platforms, Power Supply Monitoring and Battery Management.
Industrial Control and Sensor Signal Conditioning
The PIC18F4320-E/P fits industrial control boards because its 40-pin PDIP through-hole package withstands factory-floor vibration and the -40C to +125C extended industrial temperature grade handles unconditioned enclosures. The 13-channel 10-bit ADC reads multiple analog sensors (temperature, pressure, flow) sequentially, while the 2 CCP PWM modules drive proportional valves or indicator LEDs. nanoWatt Sleep mode lets battery-backed nodes sleep below 1 uA between sensor scans. Place a 0.1 uF ceramic decoupling capacitor within 0.25 inch of each VDD/VSS pin pair, and provide bulk 10 uF on the 5V rail. The 8 KB Flash accommodates finite-state-machine control code plus a Modbus RTU slave over the AUSART port without needing external memory.
Recommended
Automotive Body Electronics and HVAC
The PIC18F4320-E/P suits automotive body controllers and HVAC modules thanks to its extended -40C to +125C temperature rating matching under-hood thermal stress. The PIC18 core's 10 MIPS at 40 MHz runs control loops for blower motors, blend doors, and stepper actuation, while the 2 CCP PWM channels dim backlights or drive MOSFET gates. The 13-channel ADC samples cabin and outside temperature sensors; analog comparators detect overcurrent on the blower driver. Use the MSSP in I2C mode to drive an OLED or character-LCD display, and the AUSART for LIN-bus slave communication. The 40-pin PDIP footprint simplifies through-hole assembly on rugged HVAC boards and field-serviceable automotive modules.
Recommended
Consumer Appliance Control Boards
The PIC18F4320-E/P integrates a complete control system for washing machines, dishwashers, and microwave ovens. Its 8 KB Flash stores user-interface state machines plus appliance-specific safety routines; 256 bytes of EEPROM retain last-cycle settings across power cycles. The 2 CCP modules generate PWM for triac-fired heater elements and motor speed control, while the 13 ADC channels monitor water level, temperature, and door-latch current. The MSSP SPI interface drives an LED-segment or TFT display, and 2 USARTs enable communication with an external wireless module for smart-appliance retrofit. Through-hole PDIP mounting survives the high-vibration, high-temperature interior of appliances.
Recommended
HVAC Thermostats and Building Automation
The PIC18F4320-E/P serves as the central controller in programmable thermostats and building-automation nodes. Its 5V supply matches standard 24 VAC thermostats after rectification, while the extended -40C to +125C grade handles plenum-temperature spikes. The 13-channel ADC reads multiple thermistor inputs for multi-zone averaging; 2 CCP modules drive PWM-controlled damper motors or variable-speed fan stages. nanoWatt Sleep with Real-Time Clock interrupts keeps standby power under 1 mA on battery-backed nodes. The MSSP I2C bus connects to a CO2 sensor and EEPROM for schedule storage; the AUSART links to a Modbus or BACnet bridge for whole-building integration through the 40-pin PDIP footprint.
Recommended
Motor Control and PWM Driver Stages
The PIC18F4320-E/P is well-suited for BLDC, brushed DC, and stepper-motor control in the 1-5A range. Two CCP PWM channels provide complementary outputs for H-bridge drivers, while the 13 ADC channels sample phase currents through shunt resistors and back-EMF sensing on the motor terminals. The 40 MIPS core executes field-oriented-control loops in software with deterministic timing. PIC18 nanoWatt Technology enables Sleep between PWM cycles when the motor is idle, dropping supply current to under 1 uA. The MSSP SPI bus synchronizes with external gate-driver ICs and the AUSART feeds back telemetry to a host controller via RS-485 in industrial servo systems.
Recommended
Educational and Development Prototyping Platforms
The PIC18F4320-E/P is a long-time favorite for university embedded-systems courses and hobbyist prototyping because its 40-pin PDIP through-hole package fits standard breadboards and 0.1-inch-pitch perfboard without soldering. The PIC18 instruction set is well-documented, and Microchip's MPLAB X IDE with XC8 compiler supports the device fully. The 8 KB Flash and 512-byte SRAM are sufficient for teaching RTOS concepts, communication stacks, and peripheral-driven designs; the 2 CCP, 2 comparator, and 13 ADC channels give students multiple real-world interfaces to explore. ICD via PGC/PGD pins enables in-circuit debugging on student-built hardware, and the -E temperature grade allows outdoor lab projects.
Recommended
Power Supply Monitoring and Battery Management
The PIC18F4320-E/P can serve as the supervisory controller in UPS systems, solar charge regulators, and battery-monitoring front-ends. Its 13-channel ADC simultaneously samples battery voltage, charge current, individual cell voltages (with external MUX), and temperature sensors for thermal protection. The 2 CCP PWM channels drive MOSFET gate signals for synchronous-rectifier buck/boost converters; the MSSP I2C port links to a stack monitor IC such as the MCP3421 ADC. nanoWatt Sleep with periodic ADC wake-up keeps quiescent draw below 50 uA in standby. The 40-pin PDIP through-hole package simplifies field retrofits into legacy power-electronics enclosures requiring rugged mechanical mounting.
Recommended
Recommended Products Summary
Engineering reference data for PIC18F4320-E/P — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC18F4320-I/P | PIC18F4220-E/P | PIC18F4321-E/P | PIC18F4331-E/P | PIC18F4431-E/P |
|---|---|---|---|---|---|---|
| Package | PDIP-40 | PDIP-40 (same) | PDIP-40 (same) | PDIP-40 (same) | PDIP-40 (same) | PDIP-40 (same) |
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Program Flash | 8 KB | 8 KB | 4 KB | 16 KB | 8 KB | 8 KB |
| SRAM | 512 B | 512 B | 256 B | 768 B | 512 B | 512 B |
| EEPROM | 256 B | 256 B | 256 B | 256 B | 256 B | 256 B |
| Max Clock | 40 MHz / 10 MIPS | 40 MHz / 10 MIPS | 40 MHz / 10 MIPS | 40 MHz / 10 MIPS | 40 MHz / 10 MIPS | 40 MHz / 10 MIPS |
| Operating Temperature | -40C to +125C (E-grade) | -40C to +85C (I-grade) | -40C to +125C (E-grade) | -40C to +125C (E-grade) | -40C to +125C (E-grade) | -40C to +125C (E-grade) |
| ADC Channels | 13 x 10-bit | 13 x 10-bit | 13 x 10-bit | 13 x 10-bit | 9 x 10-bit | 9 x 10-bit |
| PWM Channels | 2 | 2 | 2 | 2 | 6 | 6 |
| Supply Voltage | 4.2 V to 5.5 V | 4.2 V to 5.5 V | 4.2 V to 5.5 V | 4.2 V to 5.5 V | 4.2 V to 5.5 V | 4.2 V to 5.5 V |
Key Differentiators
- Extended industrial -40C to +125C temperature grade (vs PIC18F4320-I/P)
- Pin-compatible Flash upgrade path (vs PIC18F4321-E/P)
- Motor-control peripheral upgrade via same package (vs PIC18F4431-E/P)
Design Notes
Place a 0.1 uF ceramic decoupling capacitor within 0.25 inch (6 mm) of each VDD/VDD pair, plus a bulk 10 uF tantalum or low-ESR aluminum capacitor on the 5V rail. The PIC18F4320-E/P analog section uses separate AVDD/AVSS pins (pin 39, 40) - tie AVDD directly to VDD and AVSS to VSS, each with its own 0.1 uF + 10 uF decoupling network placed within 1 cm. Use a 10 kohm pull-up on MCLR to VDD with a 100 nF cap to ground to provide a clean power-on-reset. Do not exceed 5.5 V on VDD - the device has no internal overvoltage clamp.
Route the crystal traces (OSC1/OSC2) short and symmetric, with the load capacitors placed within 5 mm of the IC pins. Keep the crystal ground return separate from digital switching currents to avoid jitter on CLKIN. For the PGC/PGD ICD pins, never place series resistors above 100 ohm - this prevents in-circuit debugger communication failures. The I2C pins RC3/RC4 require external 4.7 kohm pull-ups to VDD because the PIC18F4320-E/P MSSP open-drain outputs cannot drive the bus high. Place RC pull-ups within 25 mm of the PIC and minimize bus capacitance below 400 pF for reliable 400 kHz Fast-mode operation.
Watch for these common PIC18F4320-E/P pitfalls: (1) The -E extended industrial grade means +125C operation, not 'enhanced' - do not exceed the temperature rating. (2) The 40-pin PDIP shares pinouts with PIC18F4320-I/P but NOT with PIC18F4520 - the latter has a different pin map. (3) Self-programming requires the WRT bits in CONFIG7H set; ensure configuration fuses are programmed before bootloader deployment. (4) Brown-out Reset must be enabled in CONFIG2L for reliable 4.2 V supply operation. (5) ICD pins RB6/RB7 cannot be used as digital I/O when debugging - allocate alternative pins if RB6/RB7 are needed for the application.
Estimated: At maximum activity (40 MHz, all peripherals active, driving worst-case capacitive load on all I/O), the PIC18F4320-E/P core supply current reaches approximately 25 mA at 5.5 V, dissipating roughly 138 mW internally. The 40-pin PDIP package has a theta_JA of approximately 50 C/W in still air, yielding a junction-to-ambient rise of about 7 C above ambient at full power. This is well within the -40C to +125C operating range, but the device should not be placed adjacent to heat sources on a densely-populated PCB. Estimated input values: ICC_max = 25 mA, VDD_max = 5.5 V, theta_JA_PDIP-40 = 50 C/W (still air).
Compliance Information
RoHS compliant and lead-free (Pb-free matte-tin finish) per Microchip product environmental compliance documentation. AEC-Q100 not applicable - Microchip PIC18F4320-E/P is a general-purpose MCU not specifically AEC-Q100 qualified; refer to PIC18F variants with -Q1 suffixes for automotive qualification.
