PIC18LF4320-I/PT - 8-Bit 40MHz 8KB Flash MCU | Microchip
MPN: PIC18LF4320-I/PT ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $9.44 | $9.44 |
| 10 | $8.62 | $86.20 |
| 100 | $7.55 | $755.00 |
| 500 | $6.65 | $3,325.00 |
| 1,000 | $5.9 | $5,900.00 |
PIC18LF4320-I/PT Overview
A PIC18 microcontroller belongs to Microchip's high-performance 8-bit family, sitting above the PIC16F mid-range parts and below the PIC24/dsPIC 16-bit families in the company's product hierarchy. The PIC18 architecture uses a 16-bit instruction word with an 8-bit data path, 77 single-word instructions, hardware multiplier, and a 32-level deep hardware stack, giving it roughly 4x the throughput of legacy PIC16 mid-range devices at the same clock rate.
Key features of the PIC18LF4320-I/PT include 8 KB of self-programmable Flash, 512 bytes of RAM, 256 bytes of EEPROM, a 10-bit ADC with up to 13 input channels, multiple timers (Timer0/1/2/3), a 5-bit PWM module, two analog comparators, MSSP (SPI/I2C) and USART peripherals, nanoWatt Technology for power-managed Sleep modes, and ICD (In-Circuit Debugger) support via the ICSP interface. The 'nanoWatt' label indicates integrated dynamic clock switching and idle/doze modes that reduce operating current below 1 uA in Sleep.
Architecturally, the PIC18LF4320 uses a Harvard-design CPU with separate program and data buses, a peripheral pipeline that lets the CPU fetch the next instruction while peripherals complete their current cycle, and an enhanced instruction set that includes C-optimized operations. Self-programmability permits in-field firmware upgrades without external boot memory, which is essential for remote-sensor and appliance applications.
Typical applications include industrial control panels, HVAC fan/sensor controllers, low-power sensor nodes, small appliances, automotive body modules (non-AEC-Q100), instrument clusters, USB-less human-interface devices, and any 5V-tolerant 8-bit embedded design that needs moderate analog integration. The wide 2.0V-5.5V supply range also supports direct battery operation from 2x AA cells or a single Li-ion cell with boost regulation.
When designing with this part, ensure the MCLR pin has the proper 10 kohm pull-up to VDD for normal operation, place a 100 nF decoupling capacitor within 5 mm of each VDD/VSS pin pair, and reserve the PGM/RB5-RB7 pins for ICSP programming access. Code-size planning should leave at least 1 KB of Flash headroom for bootloader or future field-update logic.
Drop-in alternatives for PIC18LF4320-I/PT — 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 PIC18LF4320-I/PT (same form factor and footprint) — differing in Package, Core Architecture, Timers, Program Memory (Flash), Operating Temperature.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PIC18LF4320-I/P
✅ Drop-In✓ In Stock
$4.76 / Unit
View Datasheet →PIC18LF4320T-I/PT
✅ Drop-In✓ In Stock
$4.15 / Unit
View Datasheet →PIC18LF4320-I/ML
✅ Drop-In ⚠️ Specs Unverified📋 Reference alternative (not in catalog)
PIC18F4320-I/PT
✅ Drop-In ⚠️ Specs Unverified✓ In Stock
$3.62 / Unit
View Datasheet →PIC18F4520-I/PT
✅ Drop-In📋 Reference alternative (not in catalog)
PIC18LF4520-I/PT
✅ Drop-In ⚠️ Specs Unverified✓ In Stock
$5.21 / Unit
View Datasheet →PIC18LF4320-I/PT Maximum Ratings & Electrical Characteristics
| Core Architecture | PIC18 (8-bit Harvard) |
| CPU Speed (MIPS) | 10 MIPS at 40 MHz |
| Max Clock Frequency | 40 MHz |
| Program Memory | 8 KB (4K x 16) Flash |
| RAM | 512 bytes |
| EEPROM | 256 bytes |
| Operating Voltage Range | 2.0 V to 5.5 V |
| I/O Pins | 36 (on 44-pin package) |
| ADC | 10-bit, up to 13 channels |
| Timers | Timer0, Timer1, Timer2, Timer3 |
| PWM | 10-bit PWM, 2 channels (CCP/ECCP) |
| Comparators | 2 analog comparators |
| Communication | MSSP (SPI/I2C), EUSART (RS-232/RS-485) |
| Operating Temperature | -40 C to +85 C (Industrial) |
| Package | 44-TQFP (10x10 mm) |
| Mounting Type | Surface Mount |
| MSL Level | 3 (168 hours) |
| RoHS Status | Compliant |
PIC18LF4320-I/PT Pin Configuration
| Pin 1 | RA2/AN2/VREF- — Port A bit 2 / ADC input 2 / ADC negative reference |
| Pin 2 | RA3/AN3/VREF+ — Port A bit 3 / ADC input 3 / ADC positive reference |
| Pin 3 | RA4/T0CKI — Port A bit 4 / Timer0 clock input |
| Pin 4 | RA5/AN4/SS — Port A bit 5 / ADC input 4 / SPI slave select |
| Pin 5 | RA6/OSC2/CLKO — Port A bit 6 / oscillator output / clock output |
| Pin 6 | RA7/OSC1/CLKI — Port A bit 7 / oscillator input / clock input |
| Pin 7 | VSS — Ground reference |
| Pin 8 | VDD — Positive supply voltage (2.0V-5.5V) |
| Pin 9 | RB0/INT0/FLT0 — Port B bit 0 / external interrupt 0 / PWM fault input |
| Pin 10 | RB1/INT1 — Port B bit 1 / external interrupt 1 |
| Pin 11 | RB2/INT2 — Port B bit 2 / external interrupt 2 |
| Pin 12 | RB3/CCP2 — Port B bit 3 / Capture/Compare/PWM channel 2 |
| Pin 13 | RB4 — Port B bit 4 |
| Pin 14 | RB5/PGM — Port B bit 5 / ICSP low-voltage programming |
| Pin 15 | RB6/PGC — Port B bit 6 / ICSP clock (debugger clock) |
| Pin 16 | RB7/PGD — Port B bit 7 / ICSP data (debugger data) |
| Pin 17 | VSS — Ground reference (second pair) |
| Pin 18 | VDD — Positive supply voltage (second pair) |
| Pin 19 | RC0/T1OSO/T1CKI — Port C bit 0 / Timer1 oscillator output / Timer1 clock input |
| Pin 20 | RC1/T1OSI/CCP2 — Port C bit 1 / Timer1 oscillator input / CCP2 alt |
| Pin 21 | RC2/CCP1 — Port C bit 2 / Capture/Compare/PWM channel 1 |
| Pin 22 | RC3/SCK/SCL — Port C bit 3 / SPI clock / I2C clock |
| Pin 23 | RC4/SDI/SDA — Port C bit 4 / SPI data in / I2C data |
| Pin 24 | RC5/SDO — Port C bit 5 / SPI data out |
| Pin 25 | RC6/TX/CK — Port C bit 6 / EUSART TX / EUSART clock |
| Pin 26 | RC7/RX/DT — Port C bit 7 / EUSART RX / EUSART data |
| Pin 27 | VSS — Ground reference (third pair) |
| Pin 28 | VDD — Positive supply voltage (third pair) |
| Pin 29 | RD0/PSP0 — Port D bit 0 / parallel slave port bit 0 |
| Pin 30 | RD1/PSP1 — Port D bit 1 / parallel slave port bit 1 |
| Pin 31 | RD2/PSP2 — Port D bit 2 / parallel slave port bit 2 |
| Pin 32 | RD3/PSP3 — Port D bit 3 / parallel slave port bit 3 |
| Pin 33 | RD4/PSP4 — Port D bit 4 / parallel slave port bit 4 |
| Pin 34 | RD5/PSP5 — Port D bit 5 / parallel slave port bit 5 |
| Pin 35 | RD6/PSP6 — Port D bit 6 / parallel slave port bit 6 |
| Pin 36 | RD7/PSP7 — Port D bit 7 / parallel slave port bit 7 |
| Pin 37 | VSS — Ground reference (fourth pair) |
| Pin 38 | VDD — Positive supply voltage (fourth pair) |
| Pin 39 | RE0/RD/AN5 — Port E bit 0 / read control / ADC input 5 |
| Pin 40 | RE1/WR/AN6 — Port E bit 1 / write control / ADC input 6 |
| Pin 41 | RE2/CS/AN7 — Port E bit 2 / chip select / ADC input 7 |
| Pin 42 | AVDD — Analog positive supply |
| Pin 43 | AVSS — Analog ground reference |
| Pin 44 | MCLR/VPP — Master clear reset (active low) / programming voltage input |
Typical Applications
PIC18LF4320-I/PT is suitable for 6 applications: Industrial Control Panel, HVAC Fan and Damper Controller, Battery-Powered Wireless Sensor Node, Small Appliance Control Board, Instrument Cluster Display Controller, Human-Machine Interface (HMI) Module.
Industrial Control Panel
The PIC18LF4320-I/PT suits industrial control panels because its 10 MIPS performance and 8 KB Flash comfortably host keypad scanning, LCD driving, and Modbus RTU firmware with margin for future feature expansion. The 10-bit ADC with 13 channels directly reads 4-20 mA sensor loops via external shunt resistors, while the 2.0V-5.5V operating range tolerates the wide supply variations typical of 24V industrial backplanes. Its nanoWatt Sleep mode below 1 uA reduces idle power during standby, and the 44-TQFP package provides ruggedized mechanical leads suitable for the vibration profiles of factory-floor equipment. The integrated EUSART supports RS-485 communication through an external transceiver, while the MSSP handles SPI displays or I2C sensors without additional bus ICs. Industrial-temperature grade -40C to +85C operation matches the IEC 60068-2-1/2 environmental envelope required by most factory automation installations. The combination of self-programmable Flash and ICSP allows secure field firmware updates via the maintenance port, which is essential for production lines requiring traceable revision history.
Recommended
HVAC Fan and Damper Controller
The PIC18LF4320-I/PT is a strong fit for HVAC fan and damper controllers because the two CCP/ECCP modules deliver complementary 10-bit PWM outputs for triac-fired fan speed control and servo-driven damper positioning, eliminating dedicated motor-control ICs. Its 10-bit ADC samples thermistor temperature sensors and pressure transducers with sufficient resolution for closed-loop PID control, while the wide 2.0V-5.5V supply range supports both 5V and 3.3V system rails used in modern HVAC equipment. The nanoWatt Sleep modes reduce quiescent current to under 1 uA between active control cycles, which is critical for thermostat-style products meeting ENERGY STAR standby budgets. The MSSP peripheral drives SPI/I2C displays for the user interface, while the EUSART provides either Wi-Fi module connectivity or local BACnet/Modbus networking via an external transceiver. Industrial-temperature rating -40C to +85C handles unconditioned plenum environments where ambient temperatures swing widely. The 8 KB Flash and 512 bytes RAM accommodate state-machine control logic plus lookup tables for non-linear sensor linearization.
Recommended
Battery-Powered Wireless Sensor Node
The PIC18LF4320-I/PT is a strong choice for battery-powered wireless sensor nodes because its 2.0V-5.5V operating range allows direct connection to two alkaline AA cells, and nanoWatt Sleep mode below 1 uA extends battery life into the multi-year range typical of ZigBee or LoRa sensor deployments. The 10-bit ADC captures analog sensor data with sufficient resolution for most environmental measurements, and the MSSP/I2C bus interfaces with modern low-power sensors like the MCP9808 temperature IC or SHTC3 humidity sensor. The integrated EUSART drives UART-based radio transceivers without external protocol converters, simplifying the BOM. The ICSP programming interface enables in-field firmware updates, which is essential for remote sensor installations where physical access is impractical. The 8 KB Flash and 512 bytes RAM support MAC-layer state machines plus lightweight application protocols. Industrial temperature grade -40C to +85C ensures operation across outdoor and indoor industrial environments, while the small 44-TQFP package fits the compact form factors required for ceiling-mounted or wall-embedded sensor nodes.
Recommended
Small Appliance Control Board
The PIC18LF4320-I/PT fits small appliance designs because its PWM outputs directly drive TRIAC phase-angle control circuits for variable-speed blenders, food processors, and mixer motors, eliminating dedicated motor-driver ICs in cost-sensitive products. The 10-bit ADC reads sensor inputs such as motor current, temperature, and humidity with adequate resolution for closed-loop regulation. The integrated nanoWatt Sleep mode lets appliances meet ENERGY STAR standby requirements by drawing less than 1 uA when idle, while the wide 2.0V-5.5V supply range supports both rectified-mains-derived rails and low-voltage DC inputs. The MSSP peripheral drives LED or LCD user-interface displays, and the EUSART supports either Bluetooth or Wi-Fi modules for smart-appliance connectivity. Industrial-temperature grade -40C to +85C handles the thermal environment of enclosed motor housings. The self-programmable Flash supports field firmware updates for product-line extensions, and the 44-TQFP package offers the mechanical robustness needed for high-vibration appliance environments like blenders and washing machines.
Recommended
Instrument Cluster Display Controller
The PIC18LF4320-I/PT works well as an instrument-cluster display controller because its two PWM channels drive analog gauge movements or LED backlights directly, while the MSSP peripheral streams display data to TFT or OLED panels via SPI at multi-MHz rates. The 10-bit ADC with 13 channels reads automotive-style sensors including fuel level, oil pressure, and coolant temperature, and the 256-byte EEPROM stores non-volatile configuration such as odometer and service intervals without external memory ICs. Industrial-temperature grade -40C to +85C handles under-dash thermal environments, while the 2.0V-5.5V operating range tolerates crank-and-start voltage transients when properly bypassed. The EUSART interfaces with body-control modules via LIN or K-line transceivers, while the ICSP programming port enables production-line programming and field service updates. The 8 KB Flash and 512 bytes RAM support graphics-rendering state machines plus diagnostic-logging routines. The 44-TQFP package provides mechanical lead compliance for vibration-prone instrument-panel assemblies.
Recommended
Human-Machine Interface (HMI) Module
The PIC18LF4320-I/PT serves as an HMI module controller because its MSSP peripheral drives character LCDs or small graphic OLEDs via SPI/I2C, while the EUSART connects to a host controller for command and status exchange. The 10-bit ADC reads rotary encoder or potentiometer inputs for analog knob emulation, and the multiple timers generate precise keypad-scan waveforms without external timing ICs. The 8 KB Flash stores menu navigation state machines plus ASCII/Unicode lookup tables for multi-language support, while the 256-byte EEPROM retains user preferences across power cycles. The wide 2.0V-5.5V supply range allows direct integration with both 3.3V and 5V host systems via simple level shifting. Industrial-temperature grade -40C to +85C supports outdoor kiosks and factory-floor HMI panels, while the integrated nanoWatt Sleep mode reduces standby power below 100 uA. The 44-TQFP package provides clean mechanical footprints for SMT assembly in high-volume consumer and industrial HMI products, and ICSP enables field firmware updates for menu revisions.
Recommended
Recommended Products Summary
Engineering reference data for PIC18LF4320-I/PT — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC18LF4320-I/P | PIC18LF4320T-I/PT | PIC18LF4320-I/ML | PIC18F4320-I/PT | PIC18F4520-I/PT | PIC18LF4520-I/PT |
|---|---|---|---|---|---|---|---|
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Package | 44-TQFP (10x10 mm) | 40-PDIP (600 mil) - through-hole | 44-TQFP (10x10 mm) - same | 44-QFN (8x8 mm) | 44-TQFP (10x10 mm) - same | 44-TQFP (10x10 mm) - same | 44-TQFP (10x10 mm) - same |
| Program Flash | 8 KB | 8 KB - same | 8 KB - same | 8 KB - same | 8 KB - same | 32 KB (+300%) | 32 KB (+300%) |
| RAM | 512 bytes | 512 bytes - same | 512 bytes - same | 512 bytes - same | 512 bytes - same | 1536 bytes (+200%) | 1536 bytes (+200%) |
| EEPROM | 256 bytes | 256 bytes - same | 256 bytes - same | 256 bytes - same | 256 bytes - same | 256 bytes - same | 256 bytes - same |
| Operating Voltage | 2.0V to 5.5V (LF) | 2.0V to 5.5V - same | 2.0V to 5.5V - same | 2.0V to 5.5V - same | 4.2V to 5.5V (no low-voltage) | 4.2V to 5.5V (no low-voltage) | 2.0V to 5.5V - same |
| Max Clock | 40 MHz | 40 MHz - same | 40 MHz - same | 40 MHz - same | 40 MHz - same | 40 MHz - same | 40 MHz - same |
| ADC | 10-bit, 13 ch | 10-bit, 13 ch - same | 10-bit, 13 ch - same | 10-bit, 13 ch - same | 10-bit, 13 ch - same | 10-bit, 13 ch - same | 10-bit, 13 ch - same |
Key Differentiators
- Wide 2.0V-5.5V operating range vs 4.2V-5.5V for F-suffix variants (vs PIC18F4320-I/PT)
- Lower power draw than 32 KB Flash PIC18F4520 alternatives (vs PIC18F4520-I/PT)
- TQFP package suitable for SMT assembly vs PDIP for through-hole only (vs PIC18LF4320-I/P)
Design Notes
Estimated: At 40 MHz CPU clock, the PIC18LF4320 draws approximately 11 mA typical at 5V and 7 mA at 3.3V. Place a 100 nF decoupling capacitor within 5 mm of each VDD/VSS pair (4 pairs total on the 44-TQFP), plus a bulk 10 uF tantalum or ceramic near the package. The internal voltage regulator (LF variant only) requires an external 1 uF bypass on the VDD/VSS pair adjacent to pin 8/pin 7.
Reserve RB6 (PGC) and RB7 (PGD) pins for the ICSP programming interface and ensure they are not hardwired as outputs only - series resistors of 4.7 kohm to 10 kohm on these lines allow in-circuit programming without isolating the MCU from the rest of the board. Keep the MCLR pin pulled high with a 10 kohm resistor to VDD through a 100 nF capacitor to ground for proper reset behavior during power-up.
Do not exceed 5.5V on VDD or apply voltage to any pin before VDD is stable - the PIC18LF4320 lacks 5V-tolerant I/O on digital-only pins. The AVSS/AVDD analog supply pair must be tied to the same rails as VDD/VSS with ferrite-bead isolation if noise-sensitive ADC measurements are needed. Always configure unused I/O pins as outputs driven low to minimize Sleep-mode current consumption. Avoid the LF vs F voltage confusion - the LF4320 is required for 3.3V systems; the F4320 will brownout below 4.2V.
Compliance Information
RoHS compliant per Microchip product page. Industrial temperature grade -40C to +85C but not AEC-Q100 qualified - not suitable for automotive safety-critical applications