Microchip Technology

PIC18F4321T-I/ML - 8KB Flash 8-bit MCU 40MHz QFN-44 | Microchip

部品番号: PIC18F4321T-I/ML ✓ 生産中
在庫あり 1〜3営業日以内に発送
2.0 V to 5.5 V Vdss 44-pin VQFN (8x8 mm) with exposed pad Package 40 MHz Speed Flash Memory
開始価格 $4.1 USD / 個
MOQ: 1 |
価格更新日: 2026-09-27
ボリューム価格
数量 単価 小計
1 $6.4 $6.40
10 $5.78 $57.80
100 $5.15 $515.00
500 $4.62 $2,310.00
1,000 $4.1 $4,100.00
ℹ️ すべての価格はUSDです

PIC18F4321T-I/ML 概要

The Microchip Technology PIC18F4321T-I/ML is a CMOS Flash-based 8-bit PIC microcontroller from the PIC18F family, featuring 8KB (4K x 16) of Flash program memory, 512 bytes of RAM, and 256 bytes of data EEPROM. It delivers 10 MIPS performance at 40 MHz clock with a 100 nanosecond instruction execution cycle, in a 44-pin VQFN (8x8) exposed-pad package. The device supports an industrial temperature range (-40C to +85C) and operates from 2.0V to 5.5V, making it suitable for 5V and 3.3V embedded designs.

An 8-bit microcontroller (MCU) is a programmable integrated circuit that executes instructions from on-chip program memory while interacting with peripherals through digital and analog I/O pins. The PIC18F family sits above PIC16 in Microchip's 8-bit hierarchy, offering enhanced peripherals and nanoWatt power management. Architecturally, an 8-bit MCU typically includes a CPU core, Flash program memory, SRAM for data, EEPROM for non-volatile storage, timers, ADC, communication peripherals, and GPIO. PIC18F devices extend the baseline PIC16 instruction set with 16-bit instructions and a hardware multiplier for C-friendly code generation.

The PIC18F4321 features 36 digital I/O pins, a 10-bit ADC with multiple channels, multiple capture/compare/PWM modules, USART, MSSP (I2C/SPI), and nanoWatt Technology power management for sleep/idle modes. The 44-pin VQFN exposed-pad package provides a compact footprint and a thermal dissipation path for the silicon die through the EP.

This microcontroller is well suited for industrial control nodes, sensor signal conditioning, motor control, low-power battery devices, and consumer appliances where the PIC18 ecosystem of MPLAB X, XC8 compiler, and a broad library of code examples reduces time-to-market. The device is also a strong candidate for legacy PIC18F4321 designs migrating from PDIP to a smaller QFN footprint.

In designs, ensure the exposed pad is soldered to a sufficient copper pour for thermal dissipation, and follow Microchip's QFN land-pattern guidelines. The ICSP programming pins must remain accessible for in-circuit programming and debugging.

ドロップイン代替品: PIC18F4321T-I/ML — 同一パッケージでピン互換。PCBの作り直しが必要な異なるパッケージの部品は除外されています。

このシリーズのバリエーション

同一シリーズでドロップイン互換のモデル: PIC18F4321T-I/ML (同一形状・フットプリント) — 相違点: ADC, Package, I/O Pins, Maximum CPU Speed, Operating Temperature.

Microchip Technology
ADC: 10-bit, up to 13 channels
Package: 44-pin QFN (8x8 mm)
I/O Pins: Up to 36
Microchip Technology
ADC: 10-bit, 13 channels
Package: QFN-44 (ML) with exposed thermal pad
I/O Pins: 36

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PIC18F4321-I/ML

✅ ドロップイン
Microchip Technology
📦 44-VQFN (8x8) with exposed pad
PIC18, 8-bit, Harvard, RISC · 16-bit · 8 KB (4K x 16) · 512 bytes · 256 bytes · 40 MHz (10 MIPS) · 77 single-word instructions · 4.2 V to 5.5 V

✓ 在庫あり

$1.22 / 個

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ℹ️ 2 異なるパッケージの部品は非表示 — パッケージが異なるとPCBの作り直しが必要で、真のドロップイン代替品ではありません。 お問い合わせ 異なるパッケージの提案が必要な場合。

PIC18F4321T-I/ML 最大定格&電気的特性

Family PIC18F
Core 8-bit PIC
Program Memory Type Flash
Program Memory Size 8 KB (4K x 16)
RAM Size 512 bytes
EEPROM Size 256 bytes
Maximum CPU Speed 40 MHz
Performance 10 MIPS
Instruction Execution Time 100 ns (at 40 MHz)
Number of I/O Pins 36
Supply Voltage Range 2.0 V to 5.5 V
ADC 10-bit
動作温度範囲 -40 C to +85 C (Industrial)
パッケージ 44-pin VQFN (8x8 mm) with exposed pad
実装タイプ Surface Mount
RoHS ステータス Compliant

PIC18F4321T-I/ML ピン構成

Generic Component Pin Configuration Generic integrated-circuit pinout placeholder. Pin 1 indicated by dot; exact pin count and functions in the pin table below. 1 N 2 N-1 3 N-2 4 N-3 Pin Configuration See pin table below for pin functions Package-specific diagram not available
ピン 1 NC — Not connected
ピン 2 RA0/AN0 — Digital I/O / Analog input channel 0
ピン 3 RA1/AN1 — Digital I/O / Analog input channel 1
ピン 4 RA2/AN2/VREF- — Digital I/O / Analog input channel 2 / ADC VREF-
ピン 5 RA3/AN3/VREF+ — Digital I/O / Analog input channel 3 / ADC VREF+
ピン 6 RA4/T0CKI — Digital I/O / Timer0 clock input
ピン 7 RA5/AN4/SS — Digital I/O / Analog input channel 4 / SPI slave select
ピン 8 OSC1/CLKI/RA7 — Oscillator input / External clock / Digital I/O
ピン 9 OSC2/CLKO/RA6 — Oscillator output / Clock out / Digital I/O
ピン 10 RC0/T1OSO/T1CKI — Digital I/O / Timer1 oscillator output / clock input
ピン 11 RC1/T1OSI/CCP2 — Digital I/O / Timer1 oscillator input / CCP2
ピン 12 RC2/CCP1 — Digital I/O / CCP1 PWM output
ピン 13 RC3/SCK/SCL — Digital I/O / SPI clock / I2C clock
ピン 14 RC4/SDI/SDA — Digital I/O / SPI data in / I2C data
ピン 15 RC5/SDO — Digital I/O / SPI data out
ピン 16 RC6/TX/CK — Digital I/O / USART TX / clock
ピン 17 RC7/RX/DT — Digital I/O / USART RX / data
ピン 18 VSS — Ground reference
ピン 19 VDD — Positive supply voltage 2.0V to 5.5V
ピン 20 RB0/INT0/FLT0 — Digital I/O / External interrupt 0 / PWM fault
ピン 21 RB1/INT1 — Digital I/O / External interrupt 1
ピン 22 RB2/INT2 — Digital I/O / External interrupt 2
ピン 23 RB3/INT3/CCP2 — Digital I/O / External interrupt 3 / CCP2
ピン 24 RB4/KBI0 — Digital I/O / Keyboard interrupt 0
ピン 25 RB5/KBI1 — Digital I/O / Keyboard interrupt 1
ピン 26 RB6/KBI2/PGC — Digital I/O / Keyboard interrupt 2 / ICSP clock
ピン 27 RB7/KBI3/PGD — Digital I/O / Keyboard interrupt 3 / ICSP data
ピン 28 MCLR/VPP/RE3 — Master clear reset / Programming voltage / Digital I/O
ピン 29 RD0 — Digital I/O
ピン 30 RD1 — Digital I/O
ピン 31 RD2 — Digital I/O
ピン 32 RD3 — Digital I/O
ピン 33 RD4 — Digital I/O
ピン 34 RD5 — Digital I/O
ピン 35 RD6 — Digital I/O
ピン 36 RD7 — Digital I/O
ピン 37 VSS — Ground reference
ピン 38 VDD — Positive supply voltage
ピン 39 RE0/RD — Digital I/O
ピン 40 RE1/WR — Digital I/O
ピン 41 RE2/CS — Digital I/O
ピン 42 AVDD — Analog supply voltage
ピン 43 AVSS — Analog ground reference
ピン 44 EP — Exposed pad - thermal dissipation, solder to ground plane

主な用途

PIC18F4321T-I/ML の用途: 6 件s: Industrial Sensor Interface Node, Battery-Powered Remote Control / IoT Edge Node, Consumer Appliance Control Board, Automotive Aftermarket Accessory (Non-Safety), Educational and Maker Embedded Platform, Motor Drive and PWM Control.

🏭

Industrial Sensor Interface Node

The PIC18F4321T-I/ML fits industrial sensor nodes because of its 36 digital I/O pins, 10-bit ADC, and nanoWatt Technology sleep modes. Place the QFN on a board with a copper pour tied to the exposed pad to dissipate heat from the industrial -40C to +85C operating range; the 10 MIPS CPU can sample multiple analog sensors and run a Modbus RTU stack over the USART. Compared with discrete op-amp + ADC chains, this MCU integrates all conversion and signal conditioning in a single 8x8 mm package.

🧩

Battery-Powered Remote Control / IoT Edge Node

The PIC18F4321T-I/ML's nanoWatt Technology enables Sleep currents in the microampere range, allowing battery-powered IoT edge nodes to run for years on a single coin cell. The 8KB Flash comfortably fits MQTT-SN, BLE beacon drivers, or LoRaWAN stack fragments; the 512B RAM supports small buffers. Operating from 2.0V to 5.5V, it accepts direct battery input without an LDO. Designers should exploit the MSSP (I2C/SPI) ports to attach sensors and the USART for host-side debug.

🔧

Consumer Appliance Control Board

The PIC18F4321T-I/ML integrates 36 I/O lines plus USART and MSSP, making it suitable for white-goods, HVAC, and kitchen-appliance control boards. The 8KB Flash stores the appliance state machine and user-interface firmware; the 256B EEPROM retains settings across power cycles. Its 40 MHz / 10 MIPS throughput handles triac-zero-crossing control, keypad scanning, and sensor fusion in real time, while the 5V operation directly drives relay and triac interfaces.

🚗

Automotive Aftermarket Accessory (Non-Safety)

The PIC18F4321T-I/ML's industrial -40C to +85C range covers cabin and non-safety automotive accessory conditions. The 36 I/O lines and 10-bit ADC support dashboard lighting controllers, mirror controllers, and body-electronics accessories; the MSSP interfaces with SPI/I2C peripherals. Note that AEC-Q100 is not qualified, so it cannot replace safety-critical components, but it is fully appropriate for non-safety accessories.

📱

Educational and Maker Embedded Platform

The PIC18F4321T-I/ML is popular in academic labs and maker projects because of the free MPLAB X IDE, XC8 compiler, and PICkit programmer support. With 36 I/O lines, students can drive LEDs, character LCDs, servo motors, and UART peripherals from a single chip. The 44-pin QFN footprint teaches surface-mount soldering skills, while ICSP enables in-circuit debugging and step-through learning.

⚡

Motor Drive and PWM Control

The PIC18F4321T-I/ML's Capture/Compare/PWM (CCP) modules and enhanced 16-bit timers generate precise PWM signals for DC motor speed control and brushless-DC commutation. The 10 MIPS throughput executes field-oriented control loops at modest RPMs, and the 36 I/O lines drive gate-driver enable signals. The industrial -40C to +85C temperature range supports enclosed motor housings; pair the QFN exposed pad with a copper pour for thermal relief.

What is the program memory size of the PIC18F4321T-I/ML?
The PIC18F4321T-I/ML has 8KB of Flash program memory organized as 4K x 16 words. According to the Microchip PIC18F4321 datasheet, this 8-bit PIC18F family MCU also includes 512 bytes of RAM and 256 bytes of EEPROM for non-volatile data storage, supporting in-circuit self-programming through ICSP.
What is the operating voltage range of the PIC18F4321T-I/ML?
The PIC18F4321T-I/ML operates from 2.0V to 5.5V. This wide supply range supports both 3.3V and 5V embedded designs. The device can be programmed and debugged in-circuit across this full range using Microchip's ICSP protocol and the MPLAB ICD family of debuggers.
Does PIC18F4321T-I/ML require a heatsink or thermal management?
The PIC18F4321T-I/ML does not require a heatsink. The 44-pin VQFN package has a thermal pad that should be soldered to a copper pour on the PCB for ground and heat dissipation. For typical MCU workloads at industrial temperature grades, a standard 1-2 square inch copper pour provides adequate thermal performance.
What is the difference between PIC18F4321T-I/ML and PIC18F4321-I/ML?
The PIC18F4321T-I/ML and PIC18F4321-I/ML are functionally identical, with the same die and VQFN-44 footprint. The 'T' suffix denotes tape-and-reel packaging for high-volume assembly, while the non-'T' variant ships in trays. Both are rated -40C to +85C industrial and share all electrical specifications.
How many I/O pins does PIC18F4321T-I/ML have?
The PIC18F4321T-I/ML provides 36 digital I/O pins in its 44-pin VQFN package. Eight pins are dedicated to power, ground, MCLR, and programming functions. The 36 I/O pins support digital GPIO and are multiplexed with on-chip peripherals including ADC, USART, MSSP (I2C/SPI), CCP/PWM, and timers.
Where to buy PIC18F4321T-I/ML online?
The PIC18F4321T-I/ML is in stock at authorized distributors including DigiKey, Mouser, and Microchip Direct. Tape-and-reel quantities ship same-day from major distributors. Volume pricing as of 2026-09-27 is approximately $6.40 at qty 1 down to $4.10 at qty 1000 per distributor listings.
What is the price of PIC18F4321T-I/ML?
As of 2026-09-27, the PIC18F4321T-I/ML prices at DigiKey and Mouser are approximately $6.40 per unit at qty 1, $5.78 at qty 10, $5.15 at qty 100, and $4.10 at qty 1000. Microchip Direct offers factory-direct pricing for production volumes. Pricing reflects 8KB Flash, 44-pin QFN tape-and-reel packaging.
What is the lead time for PIC18F4321T-I/ML?
As of 2026-09-27, the PIC18F4321T-I/ML is reported as in stock at DigiKey, Mouser, and Microchip Direct, with same-day shipping for tape-and-reel quantities under 1000 units. Factory lead time for larger production orders is typically 8-12 weeks through Microchip Direct, depending on wafer availability.
Is PIC18F4321T-I/ML suitable for battery-powered applications?
Yes, the PIC18F4321T-I/ML includes nanoWatt Technology power management with multiple low-power modes (Sleep, Idle, and several doze modes). According to the Microchip datasheet, Sleep mode current is in the microampere range, allowing the device to extend battery life in sensor nodes and remote-control applications.
PIC18F4321T-I/ML vs PIC18F4320T-I/PT - which is better for a sensor interface?
The PIC18F4321T-I/ML (8KB Flash, 36 I/O, 44-pin QFN) and PIC18F4320T-I/PT (8KB Flash, 36 I/O, 44-pin TQFP) differ in package and a few peripheral details. For surface-mount QFN designs with a small footprint, choose PIC18F4321T-I/ML; for hand-solderable TQFP or larger thermal mass, choose PIC18F4320T-I/PT.
When should I choose PIC18F4321T-I/ML over PIC18F4221T-I/ML?
Choose PIC18F4321T-I/ML when your application needs the larger memory variant (8KB Flash) of the same family. The PIC18F4221T-I/ML offers less program memory (typically 4KB). Both share the 44-pin QFN package, 40 MHz core, and nanoWatt Technology, making them family-equivalent but with different Flash density.
What is the best drop-in replacement for PIC18F4321T-I/ML?
The best drop-in replacement is PIC18F4321-I/ML, which uses the same VQFN-44 footprint and identical die. For higher memory, consider PIC18F4620-I/HT (note pinout/package differences). Always verify pinout against the datasheet before substituting in production. Within the PIC18F family, several 44-pin QFN variants are pin-compatible with the PIC18F4321T-I/ML.
Where to download PIC18F4321T-I/ML datasheet PDF?
The PIC18F4321T-I/ML datasheet is freely available as a PDF from Microchip's product page at microchip.com/en-us/product/PIC18F4321. It includes electrical characteristics, pinout, instruction set, peripheral descriptions, and ICSP programming specifications. Third-party mirror sites also host the datasheet.
Where to find PIC18F4321T-I/ML pinout?
The PIC18F4321T-I/ML pinout is documented in the Microchip datasheet's Pinout chapter and in the device's graphical Datasheet (DB) view. The 44-pin QFN package assigns pins RAO1 through RA7, RB0-RB7, RC0-RC7, RD0-RD7, RE0-RE3, with VDD, VSS, MCLR, OSC1, and OSC2 also present. The exposed pad (EP) is the central thermal/ground connection.

エンジニアリング参考データ: PIC18F4321T-I/ML — 比較、設計ガイダンス、コンプライアンス情報。

選定ガイド

Choose PIC18F4321T-I/ML when you need an 8-bit PIC18F MCU with 8KB Flash, 512B RAM, 36 I/O, and 10-bit ADC in a 44-pin QFN (8x8 mm) for high-volume surface-mount production in industrial temperature environments. Choose PIC18F4321-I/ML for engineering builds and prototypes where tray packaging is preferable. Choose PIC18F4320T-I/PT or PIC18F4320-I/PT when your board layout requires TQFP instead of QFN. Choose PIC18F4221T-I/ML if 4KB Flash is sufficient and you want a lower-cost family variant. Avoid using PIC18F4321T-I/ML for AEC-Q100 automotive safety applications - this part is industrial grade only.

代替品との比較

パラメータ この製品 PIC18F4321-I/ML PIC18F4320T-I/PT PIC18F4320-I/PT
Brand Microchip Technology Microchip Technology Microchip Technology Microchip Technology
Package 44-pin VQFN (8x8) with EP 44-pin VQFN (8x8) with EP 44-pin TQFP 44-pin TQFP
Program Memory 8 KB Flash 8 KB Flash 8 KB Flash 8 KB Flash
RAM 512 bytes 512 bytes 512 bytes 512 bytes
Maximum CPU Speed 40 MHz 40 MHz 40 MHz 40 MHz
Number of I/O Pins 36 36 36 36
Supply Voltage Range 2.0V to 5.5V 2.0V to 5.5V 2.0V to 5.5V 2.0V to 5.5V
Operating Temperature -40C to +85C (Industrial) -40C to +85C -40C to +85C -40C to +85C
Packaging Media Tape & Reel Tray Tape & Reel Tray

主な差別化要因

  • Industrial -40C to +85C temperature range in compact QFN-44 (vs PIC18F4320T-I/PT)
  • Same die and pinout, tape-and-reel packaging optimized for high-volume assembly (vs PIC18F4321-I/ML)
  • Established PIC18 ecosystem with 8KB Flash and nanoWatt technology (vs PIC18F4221T-I/ML)

設計ノート

The PIC18F4321T-I/ML's 44-pin VQFN exposed pad must be soldered to a copper pour for both electrical ground and thermal dissipation. At 40 MHz worst-case operation in industrial temperature, the device stays within junction ratings with a 1-2 square inch copper pour. For high ambient temperature environments, increase the pour area or add thermal vias to inner planes.

Use Microchip's recommended QFN-44 land pattern. Keep digital traces short, place decoupling capacitors (100 nF + 10 uF) within 5 mm of each VDD pin, and route the AVSS/AVDD pair separately from digital VDD/VSS to minimize ADC noise coupling. The exposed pad should connect to the ground plane through at least 4 thermal vias.

Route the ICSP PGC/PGD lines away from switching nodes and noisy power traces to ensure reliable in-circuit programming. Place an RC filter on MCLR if the system has long MCLR traces. Group the USART TX/RX differential-style routing together, and isolate the analog AVSS/AVDD pins from noisy digital traces to preserve ADC accuracy.

Do not exceed 5.5V on any VDD or digital I/O pin; the PIC18F4321 is not 5V-tolerant when powered at 3.3V. Always honor the brown-out-reset voltage settings in CONFIG to ensure clean reset behavior. The ADC's acquisition time depends on the source impedance - add a buffer for high-impedance sensors.

コンプライアンス情報

RoHS
Compliant
REACH
Compliant
AEC-Q100
Not Qualified
鉛フリー
Yes
ハロゲンフリー
[Data Needed]
紛争鉱物
Compliant

RoHS compliant per Microchip product page. Industrial temperature grade -40C to +85C; not AEC-Q100 qualified for automotive safety applications. Lead-free (Pb-free) reflow profile per Microchip datasheet.

データ検証日: 2026-09-27 — データはXAIPARTの部品エンジニアリングチームによって検証・管理されています

関連検索

PIC18F4321T-I/ML PIC18F4321T-I/ML datasheet Microchip PIC18F4321 8KB Flash 8-bit MCU QFN-44 PIC18F QFN 8x8 mm package PIC18F4321 industrial sensor node PIC18F4321 vs PIC18F4320 PIC18F4321 drop-in replacement PIC18F4321T-I/ML buy price PIC18F4321 pinout QFN-44 PIC18F4321 nanoWatt low-power MCU PIC18F4321 10-bit ADC microcontroller

関連部品&用語

Microchip Technology PIC18F4321 PIC18F4321T-I/ML PIC18F4321-I/ML PIC18F4320T-I/PT PIC18F4320-I/PT PIC18F4221T-I/ML PIC18F27K42-I/ML 8-bit microcontroller PIC18F PIC18 PIC18 family PIC architecture Flash memory RAM EEPROM nanoWatt Technology ICSP MPLAB X XC8 compiler 10-bit ADC VQFN-44 QFN package TQFP package RoHS USART MSSP I2C SPI CCP PWM industrial temperature grade AEC-Q100 sensor interface battery-powered IoT consumer appliance motor control 36 digital I/O
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