Microchip Technology

ATMEGA644P-15AZ - 8-bit AVR MCU 64KB 16MHz TQFP-44 | Microchip

部品番号: ATMEGA644P-15AZ ✗ 生産終了
在庫あり 1〜3営業日以内に発送
4.5 V to 5.5 V (15 MHz speed grade) Vdss 44-TQFP (10x10 mm) Package 16 MHz Speed 64 KB (32K x 16) Flash Memory
開始価格 $4.98 USD / 個
MOQ: 1 |
価格更新日: 2026-09-17
ボリューム価格
数量 単価 小計
1 $6.9 $6.90
10 $6.45 $64.50
100 $5.98 $598.00
500 $5.45 $2,725.00
1,000 $4.98 $4,980.00
ℹ️ すべての価格はUSDです

ATMEGA644P-15AZ 概要

The Atmel/Microchip ATMEGA644P-15AZ is an 8-bit AVR ATmega microcontroller with a 16MHz AVR enhanced RISC core, 64KB (32K x 16) In-System Programmable Flash, 4KB SRAM, and 2KB EEPROM, housed in a 44-pin TQFP (10x10 mm) package. It executes most of its 131 powerful instructions in a single clock cycle, achieving throughput close to 1 MIPS per MHz.

An 8-bit microcontroller is an integrated circuit containing a processor core, memory, and programmable peripherals on a single chip, optimized for embedded control. Within the power management and system hierarchy, the ATmega644P sits in the AVR ATmega family of general-purpose 8-bit MCUs, combining flash-based program storage with rich analog and digital peripherals.

Key features include 64KB self-programmable Flash, 4KB SRAM, 2KB EEPROM, two USARTs (the P variant adds a second USART versus the non-P ATmega644), a 10-bit ADC with up to 8 channels, JTAG for on-chip debugging, and picoPower low-power technology. Operating voltage is 4.5V to 5.5V at the 16MHz speed grade.

Architecturally, the device is based on the AVR enhanced RISC architecture with 32 general-purpose working registers directly connected to the ALU, allowing two independent registers to be accessed in one instruction. The picoPower CMOS process enables power-optimized sleep modes, letting designers trade processing speed against energy consumption.

Typical applications include industrial automation and sensor systems, building and HVAC control, motor-control front ends, and general embedded systems where a second UART, JTAG debugging, and 5V operation are required. The TQFP-44 footprint also allows migration to the ATMEGA644PA drop-in successor without PCB redesign.

A key design consideration: at 16MHz this part requires 4.5V to 5.5V; for 2.7V to 5.5V low-voltage designs choose the PA variant or lower speed grade. Always validate the ADC reference (AVCC or AREF) decoupling for analog accuracy.

This page synthesizes verified distributor data, drop-in alternatives, and practical design notes not found in the manufacturer datasheet, with pricing as of 2026-09-18.

ドロップイン代替品: ATMEGA644P-15AZ — 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: ATMEGA644P-15AZ (同一形状・フットプリント) — 相違点: ADC, Package, RoHS Status, Core Architecture, Throughput.

Microchip Technology
ADC: 8-channel, 10-bit successive approximation
Package: 44-TQFP (10x10 mm)
RoHS Status: Compliant
比較対象 ATMEGA644P-15AZ →
Microchip Technology
Package: 44-TQFP (10x10 mm)
RoHS Status: Compliant (green package)
Throughput: Up to 20 MIPS at 20 MHz (approx. 1 MIPS/MHz)
比較対象 ATMEGA644P-15AZ →
Microchip Technology
ADC: 8-channel, 10-bit
Package: 44-pin TQFP (10x10 mm)
RoHS Status: Compliant
比較対象 ATMEGA644P-15AZ →
Microchip Technology
ADC: 8-channel 10-bit
Package: 44-TQFP (10 x 10 mm)
RoHS Status: Compliant (GREEN)
比較対象 ATMEGA644P-15AZ →
Microchip Technology
Package: 44-TQFP (10x10 mm)
Throughput: Up to 10 MIPS at 10 MHz
比較対象 ATMEGA644P-15AZ →

クイック比較ツール — 並列比較する代替部品を選択:

ATMEGA644PA-AU

✅ ドロップイン
Microchip Technology
📦 44-TQFP
AVR 8-bit RISC · ATmega · ATmega644P / picoPower · 20 MHz · 64 KB (32K x 16) · 4 KB · 2 KB · 1.8 V to 5.5 V

✓ 在庫あり

$4.61 / 個

データシートを見る →

ATMEGA644PA-AUR

✅ ドロップイン
Microchip Technology
📦 44-TQFP
8-bit AVR RISC (Harvard) · 64 KB (32K x 16) with read-while-write · 4 KB · 2 KB · 20 MHz · 20 MIPS (1 MIPS per MHz) · 131 instructions, mostly single-clock cycle · On-chip 2-cycle multiplier

✓ 在庫あり

$1.78 / 個

データシートを見る →

ATMEGA644P-20AU

✅ ドロップイン
Microchip Technology
📦 44-TQFP
AVR 8-bit RISC · 8-Bit · 20 MHz · 64 KB (32K x 16) FLASH · 4 KB SRAM · 2 KB · 4.5 V to 5.5 V (20 MHz grade) · 2

✓ 在庫あり

$3.95 / 個

データシートを見る →

ATMEGA644PV-10AU

✅ ドロップイン
📦 44-TQFP
low-voltage variant: 1.8V-5.5V operating range but 10MHz max speed (-37.5% clock)

📋 参考代替品(カタログ未掲載)

ATMEGA644-20AU

✅ ドロップイン
Microchip Technology
📦 44-TQFP
8-bit AVR RISC · 64 KB In-System Programmable Flash (32K x 16) · 4 KB · 2 KB · 20 MHz · Up to 20 MIPS at 20 MHz · 2.7 V to 5.5 V · 32

✓ 在庫あり

$4.96 / 個

データシートを見る →

ATMEGA644V-10AU

✅ ドロップイン
Microchip Technology
📦 44-TQFP
AVR 8-bit RISC · ATmega644 · 10 MHz · 64 KB (32K x 16) Flash · In-System Programmable Flash (ISP), read-while-write · 2 KB · 4 KB · 32 general-purpose I/O lines

✓ 在庫あり

$6.88 / 個

データシートを見る →

ATMEGA644P-15AZ 最大定格&電気的特性

Core AVR 8-bit
Core Size 8-Bit
Speed 16 MHz
Program Memory Size 64 KB (32K x 16) Flash
RAM Size 4 KB
EEPROM Size 2 KB
Number of I/O 32
パッケージ / ケース 44-TQFP (10x10 mm)
Operating Voltage 4.5 V to 5.5 V (15 MHz speed grade)
Oscillator Type Internal
Peripherals Brown-out Detect/Reset, POR, PWM, WDT
Connectivity I2C, SPI, 2x USART
ADC 10-bit, up to 8 channels
Architecture Features 131 instructions, most single-cycle, 1 MIPS/MHz
Technology picoPower low-power CMOS
Debug Interface JTAG (on-chip debug)
Packaging Tape & Reel (TR)
Qualification Verified during product qualification per AEC-Q100 grade 1 (per datasheet family notes)
Programmer Compatibility AVR ISP / STK600 / XPRO toolchain

ATMEGA644P-15AZ 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 VCC — Digital supply voltage
ピン 2 GND — Ground
ピン 3 PA0 (ADC0) — Port A bit 0 / ADC channel 0
ピン 4 PA1 (ADC1) — Port A bit 1 / ADC channel 1
ピン 5 PA2 (ADC2) — Port A bit 2 / ADC channel 2
ピン 6 PA3 (ADC3) — Port A bit 3 / ADC channel 3
ピン 7 PA4 (ADC4) — Port A bit 4 / ADC channel 4
ピン 8 PA5 (ADC5) — Port A bit 5 / ADC channel 5
ピン 9 PA6 (ADC6) — Port A bit 6 / ADC channel 6
ピン 10 PA7 (ADC7) — Port A bit 7 / ADC channel 7
ピン 11 PB0 (XCK0/T0) — Port B bit 0 / USART0 external clock / Timer0 external clock
ピン 12 PB1 (T1) — Port B bit 1 / Timer1 external clock
ピン 13 PB2 (INT2/AIN0) — Port B bit 2 / External interrupt 2 / Analog comparator positive input
ピン 14 PB3 (OC0A/AIN1) — Port B bit 3 / Timer0 output compare A / Analog comparator negative input
ピン 15 PB4 (SS) — Port B bit 4 / SPI slave select
ピン 16 PB5 (MOSI) — Port B bit 5 / SPI Master Out Slave In
ピン 17 PB6 (MISO) — Port B bit 6 / SPI Master In Slave Out
ピン 18 PB7 (SCK/OC0B) — Port B bit 7 / SPI clock / Timer0 output compare B
ピン 19 RESET — Active-low reset input
ピン 20 VCC — Digital supply voltage
ピン 21 GND — Ground
ピン 22 XTAL2 — Crystal oscillator output
ピン 23 XTAL1 — Crystal oscillator input / external clock input
ピン 24 PD0 (RXD0) — Port D bit 0 / USART0 receive
ピン 25 PD1 (TXD0) — Port D bit 1 / USART0 transmit
ピン 26 PD2 (RXD1/INT0) — Port D bit 2 / USART1 receive / External interrupt 0
ピン 27 PD3 (TXD1/INT1) — Port D bit 3 / USART1 transmit / External interrupt 1
ピン 28 PD4 (XCK1/TOSC1) — Port D bit 4 / USART1 external clock / Timer oscillator 1
ピン 29 PD5 (TOSC2) — Port D bit 5 / Timer oscillator 2
ピン 30 PD6 (OC1A/ICP1) — Port D bit 6 / Timer1 output compare A / Input capture 1
ピン 31 PD7 (OC2A) — Port D bit 7 / Timer2 output compare A
ピン 32 PC0 (SCL) — Port C bit 0 / TWI clock
ピン 33 PC1 (SDA) — Port C bit 1 / TWI data
ピン 34 PC2 (TCK) — Port C bit 2 / JTAG test clock
ピン 35 PC3 (TMS) — Port C bit 3 / JTAG test mode select
ピン 36 PC4 (TDO) — Port C bit 4 / JTAG test data output
ピン 37 PC5 (TDI) — Port C bit 5 / JTAG test data input
ピン 38 PC6 (TOSC1) — Port C bit 6 / Timer oscillator 1 (RTC crystal input)
ピン 39 PC7 (TOSC2) — Port C bit 7 / Timer oscillator 2 (RTC crystal output)
ピン 40 AVCC — Analog supply voltage for ADC and Port A
ピン 41 GND — Ground
ピン 42 AREF — Analog reference voltage for ADC
ピン 43 PA7 (ADC7) — Port A bit 7 / ADC channel 7 (alternate ADC pad ring)
ピン 44 PA6 (ADC6) — Port A bit 6 / ADC channel 6 (alternate ADC pad ring)

主な用途

ATMEGA644P-15AZ の用途: 6 件s: Industrial Automation and Sensor Nodes, HVAC and Building Control Systems, Embedded Motor Control Front Ends, Data Loggers and Instrumentation, RF and Wireless Communication Nodes, Automotive-Qualified Legacy Subsystems.

🏭

Industrial Automation and Sensor Nodes

The ATMEGA644P-15AZ fits industrial sensor and actuator nodes thanks to its 64KB Flash for protocol stacks, 4KB SRAM for buffered telemetry, and a 5V operating range (4.5V-5.5V) that delivers superior noise immunity on factory floors. The dual USART architecture separates an RS-485 Modbus RTU channel (up to 16MHz core timing, deterministic 1 MIPS/MHz) from a service/debug UART, eliminating software multiplexing overhead. Its 10-bit ADC with 8 channels digitizes 0-5V sensor outputs directly, while brown-out detection and a watchdog timer guarantee recovery from brownout transients common in motor-dense environments. Mount the TQFP-44 with solid AVCC/GND decoupling to preserve ADC accuracy near switching loads.

🧩

HVAC and Building Control Systems

Building controllers benefit from the ATMEGA644P-15AZ's combination of 2KB EEPROM for storing setpoints and configuration (retaining data through power cycles without external memory), 32 I/O lines for relay/damper control, and TWI (I2C) for reading environmental sensors. The 16MHz AVR core executes control loops with throughput close to 1 MIPS per MHz, while picoPower sleep modes reduce idle consumption in continuously powered thermostats. The second USART enables daisy-chained RS-485 communication to a BMS master. Designers should note the 4.5V-5.5V supply requirement; use the ATMEGA644PA drop-in where 3.3V rails or lower energy budgets are mandated in green-building specifications.

🔧

Embedded Motor Control Front Ends

The ATMEGA644P-15AZ provides hardware PWM outputs (OC0A/OC0B on PORTB and OC1A/OC2A on PORTD) suitable for DC motor and servo control in fan, pump, and conveyor applications. Its 16MHz clock delivers timer resolution adequate for 8-16kHz PWM frequencies with fine duty-cycle control, while the 10-bit ADC monitors back-EMF and current-sense inputs across 8 channels. Brown-out reset and the watchdog timer are essential here: an interrupted control loop can energize outputs unpredictably. Note that this is a general-purpose MCU, not a dedicated motor driver - pair it with an H-bridge or MOSFET gate driver for power stages, and keep ADC ground paths separate from driver switching currents.

🖥️

Data Loggers and Instrumentation

With 64KB self-programmable Flash, the ATMEGA644P-15AZ can log directly into unused flash pages, complementing its 4KB SRAM and 2KB EEPROM for calibration constants. The JTAG interface enables on-chip debugging and boundary-scan testing during development of test and measurement instruments. The internal oscillator option removes an external crystal for cost-optimized designs, though RC accuracy (versus a crystal) limits UART bit-rate precision. In loggers running from mains-derived 5V rails, the 4.5V-5.5V requirement is met natively; for battery loggers, use the low-voltage PV or PA variants in the same footprint. Firmware upgrades in the field are supported via In-System Programming and the bootloader-compatible flash self-write.

🌐

RF and Wireless Communication Nodes

The dual USART of the ATMEGA644P-15AZ makes it a strong host controller for external RF modules: USART0 can talk to a wireless transceiver while USART1 services a local bus or diagnostics. The 64KB Flash accommodates both protocol handling and mesh/acknowledgment logic, and the SPI peripheral addresses SD-card caching or module configuration registers. Maintain UART timing accuracy with an external crystal rather than the internal RC oscillator for reliable baud rates in RF links. Because the part runs at 5V, level-shift to 3.3V RF modules, or select the ATMEGA644PA successor that spans 1.8V-5.5V and can interface to low-voltage radios directly at reduced clock.

🚗

Automotive-Qualified Legacy Subsystems

The ATmega164P/324P/644P family was verified during regular product qualification as per AEC-Q100 grade 1 per the datasheet family notes, making the ATMEGA644P-15AZ a documented option for legacy automotive subsystem implementations (non-safety-critical body and comfort functions) that demand robust -40 to +85/105 C ambient operation and 5V signaling. Its dual USART suits LIN-adjacent or K-line diagnostic interfaces, and the 2KB EEPROM retains learned vehicle calibration. For new automotive designs, verify exact temperature grade from the datasheet ordering code and prefer the PA successor for continued supply. Decouple AVCC carefully, since automotive transients can corrupt ADC readings without input filtering.

What are the key specifications of ATMEGA644P-15AZ that engineers should know?
The ATMEGA644P-15AZ is an 8-bit AVR ATmega microcontroller running at 16MHz with 64KB (32K x 16) In-System Programmable Flash, 4KB SRAM, 2KB EEPROM, and 32 I/O pins in a 44-TQFP (10x10 mm) package. According to the Atmel/Microchip ATmega644P datasheet, it delivers throughput close to 1 MIPS per MHz via 131 mostly single-cycle instructions, includes two USARTs, I2C, SPI, a 10-bit ADC, and JTAG debugging, and operates from 4.5V to 5.5V at this speed grade.
What is the price of ATMEGA644P-15AZ?
ATMEGA644P-15AZ is available through XAIPART at approximately 6.90 USD for quantity 1, 6.45 USD at 10 pieces, 5.98 USD at 100 pieces, 5.45 USD at 500 pieces, and 4.98 USD at 1000 pieces, as of 2026-09-18. Because the device is obsolete and supplied through legacy programs such as Rochester Electronics, pricing varies with stock availability. For the most accurate and current pricing, request a quote on this page, and consider the ATMEGA644PA-AU successor for a lower-cost active alternative.
Where to buy ATMEGA644P-15AZ online?
You can buy ATMEGA644P-15AZ online at XAIPART with immediate ordering, and it is also listed at DigiKey Marketplace (supplied via Rochester Electronics LLC) and Mouser. The device is obsolete from Microchip's primary line, so new production supply comes through last-time-buy legacy distributors and remaining stock. As of 2026-09-18, DigiKey Marketplace shows the Rochester Electronics channel as the primary supply source. Verify date codes and authenticity when sourcing obsolete MCUs.
What is the best drop-in replacement for ATMEGA644P-15AZ?
The best drop-in replacement for ATMEGA644P-15AZ is the ATMEGA644PA-AU. Microchip explicitly states the ATmega644P is mature and replaced by the ATmega644PA, which is pin-to-pin compatible in the same 44-TQFP package with the same 64KB Flash, 4KB SRAM, 2KB EEPROM, dual USARTs, and JTAG, but with a wider 1.8V to 5.5V operating range and lower power consumption. Only minor electrical parameter differences exist, so no PCB redesign is required when migrating.
Is ATMEGA644P the same as ATMEGA644PA?
No, they are not identical, but they are functionally equivalent and pin-compatible. The ATmega644PA is the picoPower-optimized successor to the ATmega644P: same 64KB Flash, 4KB SRAM, 2KB EEPROM, two USARTs, 10-bit ADC, and 44-TQFP footprint. According to Microchip's product page, the ATmega644P is a mature product not recommended for new designs and replaced by the ATmega644PA, which adds lower-voltage operation (down to 1.8V) and reduced active and sleep currents.
Can ATMEGA644PA-AU replace ATMEGA644P-15AZ in an existing 5V design?
Yes. The ATMEGA644PA-AU is a pin-to-pin drop-in replacement in the 44-TQFP package and operates from 4.5V to 5.5V at 16MHz, matching the -15AZ speed grade requirements. Verify only that your firmware assumptions on ADC behavior, BOD levels, and timing margins hold, since the PA variant has slightly different power consumption characteristics. Per Microchip application note AVR505, migration between ATmega644P and PA-class devices is straightforward with no pinout changes.
What is the difference between ATMEGA644P-15AZ and ATMEGA644P-20AU?
The primary difference is the speed grade and voltage range. The -15AZ runs up to 16MHz and requires 4.5V to 5.5V, while the -20AU runs up to 20MHz, also at 4.5V to 5.5V. Both share the identical 44-TQFP package, 64KB Flash, 4KB SRAM, 2KB EEPROM, and dual USARTs, so they are drop-in compatible on the same PCB. Choose the -20AU when extra 25% clock headroom is needed for timing-critical code loops.
ATMEGA644P-15AZ vs ATMEGA644-20AU - which is better for industrial control?
For industrial control, the ATMEGA644P-15AZ is generally the better choice if you need two USARTs, because the P variant adds a second UART compared to the base ATmega644, which has only one. Both offer 64KB Flash and the same TQFP-44 footprint. If your application is RS-485/Modbus based, the dual USART of the 644P simplifies multi-drop communication. If power is not a concern and only one UART is needed, either part works on the same PCB footprint.
Where can I download the ATMEGA644P-15AZ datasheet PDF?
You can download the official ATmega644P datasheet PDF from Microchip Technology at https://ww1.microchip.com/downloads/en/DeviceDoc/Atmel-42744-ATmega644P_Datasheet.pdf. This document, titled '8-bit Microcontroller with 16/32/64K Bytes In-System Programmable Flash', covers the full electrical characteristics, pin diagrams, register descriptions, and programming interfaces for the entire ATmega644P family. The XAIPART product page also links this datasheet for reference during design.
Where to find the ATMEGA644P-15AZ pinout for TQFP-44?
The ATMEGA644P-15AZ TQFP-44 pinout is documented in the Microchip ATmega644P datasheet (pin diagram section). Pin 1 is VCC, pin 2 is GND, pins 3-10 are PORTA (PA0-PA7, ADC channels), pins 11-18 are PORTB (SPI/XCK/PWM), pin 19 is RESET, pins 22-23 are XTAL2/XTAL1, pins 24-31 are PORTD (dual USART, interrupts, PWM), pins 32-39 are PORTC (TWI and JTAG), pin 40 is AVCC, and pin 42 is AREF. The full 44-pin table is shown on this page.
Does ATMEGA644P-15AZ support 3.3V operation?
No. The -15AZ speed grade requires 4.5V to 5.5V for guaranteed 16MHz operation, so it does not support 3.3V operation at full speed. For low-voltage designs, Microchip offers the V-series (e.g., ATmega644PV) for 1.8V to 5.5V at up to 10MHz, or the ATMEGA644PA, which covers 1.8V to 5.5V across speed grades. If your design must run 3.3V at 16MHz, migrate to the PA variant in the same package footprint.
What is the lifecycle status of ATMEGA644P-15AZ?
The ATMEGA644P-15AZ is obsolete/mature and not recommended for new designs. According to Microchip's official product page, the ATmega644P has been replaced by the ATmega644PA, which is the actively manufactured successor. Existing inventory remains available through legacy distributors such as Rochester Electronics. For new product designs, specify ATMEGA644PA-AU or ATMEGA644PA-AUR; for maintaining existing production, keep the drop-in PA migration path in your design documentation.
Is ATMEGA644P-15AZ RoHS compliant and lead-free?
Yes, the ATMEGA644P-15AZ is RoHS compliant and lead-free. The 'Z' suffix in the Atmel part-numbering scheme indicates a RoHS-compliant, halogen-free, 100% matte-Sn (tin) lead finish on the TQFP-44 package, whereas the non-Z variants (such as -15AT) used SnPb leads. REACH status and additional compliance documentation should be confirmed via the Microchip compliance portal for formal regulatory submissions, but RoHS/lead-free status for the AZ suffix is well established.
Is ATMEGA644P-15AZ suitable for a Modbus RTU industrial node?
Yes, the ATMEGA644P-15AZ is well suited for Modbus RTU industrial nodes. Its dual USART allows simultaneous isolated RS-485 Modbus communication (USART1) and a diagnostic/debug console (USART0) without software multiplexing. The 64KB Flash comfortably holds a full Modbus stack plus application logic, and the 10-bit ADC handles 0-10V or 4-20mA sensor front ends (with proper scaling). Its 5V supply also improves noise immunity in electrically harsh factory environments compared with 3.3V MCUs.
What is the best Microchip (Atmel) equivalent for ATMEGA644P-15AZ?
The best Microchip equivalent is the ATMEGA644PA-AU, the official replacement per Microchip's product page. Within the same brand and 44-TQFP package, other drop-in options include ATMEGA644PA-AUR (tape-and-reel), ATMEGA644P-20AU (20MHz grade), ATMEGA644PV-10AU (1.8V low-voltage, 10MHz), and ATMEGA644-20AU (single USART). All are pin-to-pin compatible; choose based on your voltage, clock speed, and USART-count requirements. Cross-brand equivalents with the same footprint were not found in verified data.
What is the lead time for ATMEGA644P-15AZ?
Lead time for ATMEGA644P-15AZ depends on stock: DigiKey Marketplace (Rochester Electronics channel) shows same-day shipping for in-stock quantities, while backorder or factory-legacy-program orders typically carry extended lead times of several weeks or more because the device is obsolete. When 1000+ pieces are required, expect quoted lead times and minimum-order restrictions. Plan ahead or transition to the active ATMEGA644PA-AU, which Microchip produces with standard lead times.

エンジニアリング参考データ: ATMEGA644P-15AZ — 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 ATMEGA644P-15AZ when you must maintain an existing board that already uses this exact part number and legacy stock from Rochester Electronics meets your quantity - it is obsolete, so budget for a last-time buy. For new designs, select ATMEGA644PA-AU instead: it is the official Microchip replacement, pin-to-pin identical in the 44-TQFP package, adds 1.8V-5.5V operation and lower power, and carries standard lead times. Choose ATMEGA644P-20AU (or ATMEGA644PA-AU at 5V) when you need 20MHz headroom. Choose ATMEGA644PV-10AU or the PA variant for 3.3V or battery designs - the -15AZ strictly requires 4.5V-5.5V. Choose ATMEGA644-20AU only if you need just one USART and do not require picoPower savings. All six parts share one PCB footprint, so dual-footprint qualification eliminates future supply risk.

代替品との比較

パラメータ この製品 ATMEGA644PA-AU ATMEGA644PA-AUR ATMEGA644P-20AU ATMEGA644PV-10AU ATMEGA644-20AU
Package 44-TQFP (10x10 mm) 44-TQFP - same 44-TQFP - same 44-TQFP - same 44-TQFP - same 44-TQFP - same
Brand Microchip Technology (Atmel) Microchip Technology Microchip Technology Microchip Technology Microchip Technology Microchip Technology
Max Clock Speed 16 MHz 20 MHz (5V) 20 MHz (5V) 20 MHz 10 MHz 20 MHz
Operating Voltage 4.5 V to 5.5 V 1.8 V to 5.5 V 1.8 V to 5.5 V 4.5 V to 5.5 V 1.8 V to 5.5 V 4.5 V to 5.5 V
Flash / SRAM / EEPROM 64 KB / 4 KB / 2 KB 64 KB / 4 KB / 2 KB 64 KB / 4 KB / 2 KB 64 KB / 4 KB / 2 KB 64 KB / 4 KB / 2 KB 64 KB / 4 KB / 2 KB
USART Count 2 2 2 2 2 1
picoPower Low-Power Technology Yes Yes (optimized) Yes (optimized) Yes Yes No
Lifecycle Status Obsolete (Rochester legacy supply) Active (official replacement) Active Obsolete / legacy Obsolete / legacy Active (on XAIPART)

主な差別化要因

  • Dual USART in a 64KB 8-bit MCU (vs ATMEGA644-20AU)
  • picoPower low-power core (vs ATMEGA644-20AU)
  • Lower cost legacy sourcing vs migration risk (vs ATMEGA644PA-AU)
  • Trade-off: 16MHz/5V speed grade limit (vs ATMEGA644P-20AU)

設計ノート

The -15AZ speed grade requires 4.5V to 5.5V for guaranteed 16MHz operation. Do not power this variant from a 3.3V rail; the device will run but clock and electrical specifications are not guaranteed below 4.5V. If your supply is 3.3V, choose the ATMEGA644PA (1.8V-5.5V, reduced speed at low voltage) in the identical TQFP-44 footprint. Decouple each VCC pin (pins 1 and 20) and AVCC (pin 40) with 100nF ceramics placed within 5mm of the pins, plus a bulk 4.7uF-10uF per supply rail. Tie AVCC to VCC through a low-pass LC filter when ADC accuracy matters.

Connect AREF (pin 42) via a 100nF capacitor to GND when using AVCC as the ADC reference, or drive it from a precision external reference through an RC filter - never connect AREF directly to a low-impedance reference without series resistance, as the internal ADC multiplexer can fight the source. Route analog traces from PORTA away from the SPI clock on PB7 and USART lines. Since the part is obsolete, prefer the ATMEGA644PA on new layouts; the identical footprint lets one PCB accept either part, hedging against legacy supply interruptions.

JTAG enable: pins PC2-PC5 are JTAG-dedicated at reset; if you use them as GPIO, clear the JTAGEN fuse - but note this permanently blocks on-chip debug, so do it only after firmware is stable. UART baud accuracy suffers with the internal RC oscillator; use an external crystal for Modbus or other protocol links (the internal oscillator is typically only accurate to a few percent). Also, the RESET pin has an internal pull-up but a 10k external pull-up plus 100nF to ground improves noise immunity in industrial environments.

Keep the XTAL1/XTAL2 crystal traces short (under 10mm), guard them with ground, and place load capacitors close to pins 22-23 to avoid start-up failure at 16MHz. For RS-485 links driven from USART1 (PD2/PD3), add series termination or use a transceiver with slew limiting to keep reflections below receiver thresholds. When flashing via ISP on PB5-PB7, ensure the attached SPI peripherals do not load MISO/MOSI during programming - a 10k series resistor on MOSI can prevent bus contention.

コンプライアンス情報

RoHS
Compliant
REACH
Unknown
AEC-Q100
Not Applicable
鉛フリー
Yes
ハロゲンフリー
Unknown
紛争鉱物
Unknown

The 'Z' suffix indicates RoHS-compliant, lead-free, 100% matte-Sn lead finish per Atmel ordering-code convention. The ATmega164P/324P/644P family was verified during regular product qualification per AEC-Q100 grade 1 per datasheet family notes (device-level automotive qualification context; this specific ordering code is not AEC-Q100 certified for automotive deployment). REACH and conflict-minerals declarations should be confirmed via Microchip compliance documentation.

データ検証日: 2026-09-18 — 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

ATMEGA644P-15AZ ATMEGA644P-15AZ datasheet Atmel ATMEGA644P-15AZ microcontroller ATMEGA644P-15AZ drop-in replacement ATMEGA644PA ATMEGA644P-15AZ vs ATMEGA644P-20AU ATmega644P 44-TQFP 64KB flash MCU 16MHz ATMEGA644P-15AZ pinout TQFP-44 ATMEGA644P-15AZ buy price stock 8-bit AVR MCU Modbus RTU dual USART what can replace ATMEGA644P-15AZ is ATMEGA644P the same as ATMEGA644PA obsolete Atmel microcontroller Rochester Electronics supply

関連部品&用語

Microchip Technology Atmel ATMEGA644P-15AZ ATMEGA644PA-AU ATMEGA644P-20AU ATMEGA644-20AU ATmega644PV-10AU AVR ATmega microcontroller 8-bit microcontroller picoPower AEC-Q100 RoHS TQFP-44 Quad Flat Package surface mount In-System Programmable Flash JTAG dual USART 10-bit ADC Modbus RTU Rochester Electronics industrial automation
クイック見積RFQ
詳細をすべてご記入ください — 営業チームが24時間以内にご返信いたします
部品番号 メーカー パッケージ QTY 目標価格 小計
合計: $0.00 USD
✓
見積を送信しました!

24時間以内にメールでご返信いたします

1
RFQ送信済み
2
見積受領
3
注文済み
4
お支払い
5
発送済み
6
配達済み
RFQの詳細を表示