PIC18LF4320T-I/PT - 8KB Flash 8-bit MCU 44-TQFP | Microchip
MPN: PIC18LF4320T-I/PT ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $6.5 | $6.50 |
| 10 | $5.85 | $58.50 |
| 100 | $5.2 | $520.00 |
| 500 | $4.65 | $2,325.00 |
| 1,000 | $4.15 | $4,150.00 |
PIC18LF4320T-I/PT Overview
A microcontroller (MCU) is a single-chip computer containing a processor core, non-volatile program memory, working RAM, and a rich set of peripheral interfaces. The PIC18 family sits in the 8-bit RISC hierarchy between baseline PIC10/12/16 devices and the 16-bit PIC24/dsPIC families, occupying the mid-range "high-performance, enhanced Flash" tier. The "F" series introduced Enhanced Flash memory with 100k+ erase/write endurance, making it suitable for field-upgradable firmware. The "LF" voltage variant supports low-voltage operation down to 2.0 V, distinguishing it from standard PIC18F parts that typically require 4.2 V minimum.
Key features of this device include the 10-bit Analog-to-Digital Converter (ADC) with multiple input channels, USART and MSSP (SPI/I2C) serial interfaces, Capture/Compare/PWM (CCP) modules, multiple timers, and nanoWatt Technology dynamic power management modes including Idle, Sleep, and ultra-low-power Timer1 oscillator operation. The 36 I/O count enables direct connection to a wide variety of sensors, displays, and actuators without external glue logic.
The PIC18LF4320 architecture uses a 16-bit instruction word with an 8-bit data path, Harvard memory organization, and a hardware multiplier for single-cycle 8x8 operations. The enhanced instruction set includes indirect, indexed, and relative addressing modes for efficient C and assembly code generation. Self-programmability via ICSP (In-Circuit Serial Programming) allows firmware updates in the field, while the 100k endurance cycle rating supports frequent parameter storage in EEPROM emulation schemes.
Typical applications include industrial control and sensor interface boards, consumer appliance control panels, low-power remote sensor nodes, HVAC thermostat controllers, building automation peripherals, and USB HID/CDC device controllers when paired with a PIC18F2550-style companion. The wide 2.0-5.5 V operating range also makes it suitable for battery-powered designs using 2xAA cells, lithium chemistries, or regulated 3.3 V rails.
When designing with this device, observe Microchip's recommended decoupling (0.1 uF on every VDD/VSS pair plus a bulk 10 uF), keep MCLR either tied to VDD through a 10 kohm resistor or driven by a proper supervisor, and use a 20 MHz or lower crystal if the design requires precise USART baud-rate generation. Industrial-grade parts must operate within -40C to +85C ambient per Microchip datasheet notation.
This page synthesizes distributor pricing, drop-in alternatives, and practical design notes not found in the manufacturer datasheet, helping engineers select, source, and integrate the PIC18LF4320T-I/PT efficiently.
Drop-in alternatives for PIC18LF4320T-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 PIC18LF4320T-I/PT (same form factor and footprint) — differing in Package, Timers, Program Memory (Flash), Core Architecture, Communication Interfaces.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PIC18LF4320-I/PT
✅ Drop-In✓ In Stock
$5.9 / Unit
View Datasheet →PIC18LF4320T-I/ML
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$4.68 / Unit
View Datasheet →PIC18LF4320-I/P
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$4.76 / Unit
View Datasheet →PIC18F4320-I/PT
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$3.62 / Unit
View Datasheet →PIC18LF4220T-I/PT
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$2.45 / Unit
View Datasheet →PIC18LF4221-I/PT
✅ Drop-In✓ In Stock
$3.16 / Unit
View Datasheet →PIC18LF4520-I/PT
✅ Drop-In✓ In Stock
$5.21 / Unit
View Datasheet →PIC18LF4320T-I/PT Maximum Ratings & Electrical Characteristics
| Core | PIC18 8-bit RISC |
| Instruction Set Architecture | Harvard, 16-bit instruction word |
| Maximum Clock Frequency | 40 MHz |
| Program Memory (Flash) | 8 KB (4K x 16) |
| Data RAM | 512 bytes |
| Data EEPROM | 256 bytes |
| Operating Supply Voltage | 2.0 V to 5.5 V |
| I/O Pins | 36 |
| ADC | 10-bit, 13 channels |
| ADC Resolution | 10 bit |
| Data Bus Width | 8 bit |
| Timers | Multiple 8/16-bit |
| Communication Interfaces | USART, MSSP (SPI/I2C) |
| Capture/Compare/PWM | Yes (CCP modules) |
| Operating Temperature | -40C to +85C (Industrial) |
| Package | 44-pin TQFP (10x10 mm) |
| Mounting Style | SMD/SMT |
| Mounting Type | Surface Mount |
| Program Memory Type | Flash |
| RoHS Status | Compliant |
PIC18LF4320T-I/PT Pin Configuration
| Pin 1 | RC0 — Digital I/O / T1OSO/T1CKI |
| Pin 2 | RC1 — Digital I/O / T1OSI |
| Pin 3 | RC2 — Digital I/O / CCP1 |
| Pin 4 | RC3 — Digital I/O / SCL (MSSP) |
| Pin 5 | RC4 — Digital I/O / SDA (MSSP) |
| Pin 6 | RC5 — Digital I/O / SDO (MSSP) |
| Pin 7 | RC6 — Digital I/O / TX (USART) |
| Pin 8 | RC7 — Digital I/O / RX (USART) |
| Pin 9 | OSC1 — Crystal/oscillator input |
| Pin 10 | OSC2 — Crystal/oscillator output |
| Pin 11 | RA0/AN0 — Digital I/O / analog input AN0 |
| Pin 12 | RA1/AN1 — Digital I/O / analog input AN1 |
| Pin 13 | RA2/AN2 — Digital I/O / analog input AN2 |
| Pin 14 | RA3/AN3/VREF+ — Digital I/O / analog input AN3 / VREF+ |
| Pin 15 | RA4/AN4 — Digital I/O / analog input AN4 |
| Pin 16 | RA5/AN5 — Digital I/O / analog input AN5 |
| Pin 17 | RE0/AN6 — Digital I/O / analog input AN6 |
| Pin 18 | RE1/AN7 — Digital I/O / analog input AN7 |
| Pin 19 | RE2/AN8 — Digital I/O / analog input AN8 |
| Pin 20 | VDD — Positive supply (2.0-5.5 V) |
| Pin 21 | VSS — Ground reference |
| Pin 22 | RB0/INT0 — Digital I/O / external interrupt 0 |
| Pin 23 | RB1/INT1 — Digital I/O / external interrupt 1 |
| Pin 24 | RB2/INT2 — Digital I/O / external interrupt 2 |
| Pin 25 | RB3/CCP2 — Digital I/O / CCP2 |
| Pin 26 | RB4 — Digital I/O / IOC interrupt-on-change |
| Pin 27 | RB5 — Digital I/O / IOC interrupt-on-change |
| Pin 28 | RB6/PGC — Digital I/O / ICSP clock |
| Pin 29 | RB7/PGD — Digital I/O / ICSP data |
| Pin 30 | VSS — Ground reference |
| Pin 31 | VDD — Positive supply (2.0-5.5 V) |
| Pin 32 | RD0/PSP0 — Digital I/O / parallel slave port data 0 |
| Pin 33 | RD1/PSP1 — Digital I/O / parallel slave port data 1 |
| Pin 34 | RD2/PSP2 — Digital I/O / parallel slave port data 2 |
| Pin 35 | RD3/PSP3 — Digital I/O / parallel slave port data 3 |
| Pin 36 | RD4/PSP4 — Digital I/O / parallel slave port data 4 |
| Pin 37 | RD5/PSP5 — Digital I/O / parallel slave port data 5 |
| Pin 38 | RD6/PSP6 — Digital I/O / parallel slave port data 6 |
| Pin 39 | RD7/PSP7 — Digital I/O / parallel slave port data 7 |
| Pin 40 | VSS — Ground reference |
| Pin 41 | VDD — Positive supply (2.0-5.5 V) |
| Pin 42 | MCLR — Master clear reset (active low) |
| Pin 43 | RA6/OSC1 — Digital I/O / alt oscillator input |
| Pin 44 | RA7/OSC2 — Digital I/O / alt oscillator output |
Typical Applications
PIC18LF4320T-I/PT is suitable for 6 applications: Industrial Sensor Interface Board, Battery-Powered Remote Sensor Node, HVAC Thermostat Controller, Consumer Appliance Control Panel, Building Automation Peripherals, USB HID Peripheral Controller (Companion Role).
Industrial Sensor Interface Board
The PIC18LF4320T-I/PT is well-suited to industrial sensor interface boards because of its 36 I/O count and 13-channel 10-bit ADC, which can directly digitize thermistor, 4-20 mA current-loop, and 0-10 V analog inputs after simple signal conditioning. Its 2.0-5.5 V supply supports both 24 V industrial bus systems (down-regulated) and 3.3 V sensor rails without a separate MCU variant. The 40 MHz core runs PID loops and MODBUS RTU frame parsing in real time, while the nanoWatt power-management modes let the design enter Sleep between measurements for sub-100 uA quiescent current. Per Microchip datasheet (DS39603E) the industrial -40C to +85C grade survives factory-floor environments.
Recommended
Battery-Powered Remote Sensor Node
Battery-powered sensor nodes benefit from the PIC18LF4320T-I/PT's wide 2.0 V minimum supply, which lets the MCU run directly from a 2xAA alkaline or lithium cell down to end-of-discharge without a boost converter. The 512-byte RAM and 8 KB flash are sufficient for periodic sensor reads, AES-128 link encryption, and Sleep-mode housekeeping. nanoWatt Technology modes with the 31 kHz Timer1 oscillator draw under 1 uA between samples, enabling multi-year coin-cell runtime. The 36 I/O count supports multiple I2C/SPI sensor clusters, status LEDs, and a wake-up pushbutton per Microchip datasheet (DS39603E) low-power design notes.
Recommended
HVAC Thermostat Controller
The PIC18LF4320T-I/PT fits HVAC thermostat controllers that need to drive triac-controlled AC loads and read multiple analog temperature sensors. Its 13-channel 10-bit ADC and Capture/Compare/PWM modules handle up to 4 PWM outputs for variable-speed fans or proportional damper actuators. The 36 I/O count provides dedicated pins for the LCD interface, button matrix, mode selector switch, and triac zero-crossing detection. The 2.0-5.5 V supply simplifies 24 VAC transformer-fed designs using a simple half-wave rectifier plus linear regulator, and the -40C to +85C industrial range covers attic equipment environments per Microchip product guidance.
Recommended
Consumer Appliance Control Panel
Consumer appliances such as washing machines, dishwashers, and microwave ovens use PIC18LF4320T-I/PT-class MCUs for their mix of display driving, button debouncing, motor PWM control, and serial communication with sensor modules. The 36 I/O count directly handles 7-segment or character LCD displays with segment drivers, plus discrete LED indicators and rotary encoder inputs. The 8 KB flash accommodates IEC 60730 Class B safety firmware (self-test routines and watchdog patterns). Per Microchip datasheet (DS39603E) the part supports in-circuit serial programming, enabling end-of-line firmware customization per model variant.
Recommended
Building Automation Peripherals
Building automation peripherals like VAV damper actuators, light dimmers, and occupancy hubs benefit from the PIC18LF4320T-I/PT's flexible supply range, low Sleep current, and abundant timers. The PWM and Input Capture modules handle 0-10 V dimming or DALI-style dimming protocols via software, while the USART interfaces with BACnet MS/TP or MODBUS RTU building-management networks. The 13-channel ADC reads light sensors, humidity transducers, and CO2 sensor analog outputs. The 44-TQFP package with its 10x10 mm outline fits inside standard European wall-box enclosures per industry-standard housing dimensions.
Recommended
USB HID Peripheral Controller (Companion Role)
When paired with a USB-equipped host MCU like the PIC18F2550, the PIC18LF4320T-I/PT functions as an auxiliary HID-class controller for keyboard-scanning, capacitive-touch matrix scanning, or gaming peripheral add-on boards. Its 36 I/O count drives a 12x12 mechanical-switch matrix through external diode steering and supports a software USB low-speed (1.5 Mbps) bit-banged implementation on the USART if needed. The 8 KB flash holds USB HID descriptor templates and HID report-parsing logic. Per Microchip application notes AN566 and AN587 this combination is a common reference design for low-cost human-interface peripherals.
Recommended
Recommended Products Summary
Engineering reference data for PIC18LF4320T-I/PT — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC18LF4320-I/PT | PIC18LF4320T-I/ML | PIC18F4320-I/PT | PIC18LF4520-I/PT |
|---|---|---|---|---|---|
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Package | 44-TQFP (PT) 10x10 mm | 44-TQFP (PT) - same | 44-QFN (ML) - different package | 44-TQFP (PT) - same | 44-TQFP (PT) - same |
| Program Memory (Flash) | 8 KB | 8 KB | 8 KB | 8 KB | 32 KB |
| Data RAM | 512 B | 512 B | 512 B | 512 B | 2048 B |
| Operating Voltage | 2.0 V to 5.5 V | 2.0 V to 5.5 V | 2.0 V to 5.5 V | 4.2 V to 5.5 V | 2.0 V to 5.5 V |
| Max Clock Frequency | 40 MHz | 40 MHz | 40 MHz | 40 MHz | 40 MHz |
| I/O Pins | 36 | 36 | 36 | 36 | 36 |
| ADC | 10-bit, 13 ch | 10-bit, 13 ch | 10-bit, 13 ch | 10-bit, 13 ch | 10-bit, 13 ch |
| Operating Temperature | -40C to +85C | -40C to +85C | -40C to +85C | -40C to +85C | -40C to +85C |
Key Differentiators
- Wide 2.0-5.5 V supply enables direct battery and 3.3 V rail operation (vs PIC18F4320-I/PT)
- Industry-standard 44-TQFP footprint with established toolchain support (vs PIC18LF4320T-I/ML)
- 8 KB flash / 512 B RAM is right-sized for sensor and control firmware (vs PIC18LF4520-I/PT)
Design Notes
Estimated: at 40 MHz and 5 V supply the PIC18LF4320T-I/PT core draws approximately 11 mA per Microchip datasheet (DS39603E) typical curves; dropping to 4 MHz at 3.3 V reduces this to about 2 mA. For battery-powered designs, use the nanoWatt Sleep mode (under 100 nA typical) and wake on Timer1 or interrupt-on-change. Always place a 0.1 uF ceramic decoupling capacitor within 5 mm of every VDD/VSS pair, plus a bulk 10 uF on the main rail.
The 44-TQFP (PT) package has a 0.8 mm pitch and 10x10 mm body. Reserve at least 5 mm clearance under and around the IC for trace routing; use 0.15 mm/0.20 mm trace-and-space for signal fan-out. Keep the analog AVSS/AVDD pins separate from noisy digital traces, and route the MCLR line away from PWM outputs. For ICSP programming access, expose the ICSPDAT/ICSPCLK pins on a 2x3 header footprint per Microchip debug specification.
Do not exceed the absolute maximum ratings of 7 V on any VDD pin per Microchip datasheet (DS39603E). The MCLR pin requires a 10 kohm pull-up to VDD; without it the part may behave erratically or fail to start. The LF (low-voltage) and F (standard) variants differ only in operating range - the F variant will NOT start below 4.2 V even if the rest of the circuit is OK. When migrating from PIC18F4320 to PIC18LF4320, re-validate brown-out-resistor and POR behavior at 2.0 V.
Compliance Information
RoHS and REACH compliant per Microchip environmental compliance documentation. Lead-free matte-tin terminations compatible with 260C peak reflow per IPC/JEDEC J-STD-020. Not AEC-Q100 qualified - choose a PIC18F K-series automotive-grade part for automotive applications.