Microchip Technology

ATMEGA644P-20MQR - 8-Bit AVR MCU 20MHz 64KB | Microchip

부품 번호: ATMEGA644P-20MQR ✗ 단종
재고 있음 영업일 기준 1~3일 내 발송
4.5 V to 5.5 V (at 20 MHz) Vdss 44-VQFN (7x7 mm) exposed pad (MLF) Package 20 MHz Speed 64 KB (32K x 16) Memory
시작가 $4.3 USD / 개
MOQ: 1 |
가격 업데이트: 2026-09-17
볼륨 가격
수량 단가 합계
1 $6.36 $6.36
10 $5.9 $59.00
100 $5.3 $530.00
500 $4.8 $2,400.00
1,000 $4.3 $4,300.00
ℹ️ 모든 가격은 USD 기준입니다

ATMEGA644P-20MQR 개요

The Microchip (Atmel) ATMEGA644P-20MQR is a high-performance, low-power 8-bit AVR RISC microcontroller running at 20 MHz with 64 KB of Flash program memory, 4 KB of SRAM, and 2 KB of EEPROM, housed in a 44-pin VQFN (7x7 mm, MLF) exposed-pad package rated for the extended industrial temperature range of -40C to +105C.

An 8-bit AVR microcontroller is a single-chip computer that combines an enhanced RISC CPU, program and data memory, and a rich set of peripherals on one die. Within the broader product hierarchy, it belongs to the ATmega family of AVR MCUs, which in turn sit under the microcontroller and embedded-processor categories of the semiconductor taxonomy.

Key features include 131 powerful instructions with mostly single-clock-cycle execution, achieving close to 1 MIPS per MHz throughput. The 'P' variant adds a second USART, giving two full-duplex serial ports, plus SPI, two-wire interface (TWI/I2C), a 10-bit 8-channel ADC, two 8-bit and one 16-bit timers, and JTAG for on-chip debugging and boundary scan. picoPower technology supports low-power sleep modes for battery-sensitive designs.

Architecturally, the device executes powerful instructions in a single clock cycle, letting system designers optimize the trade-off between processing speed and power consumption. In-system programmable (ISP) Flash via In-Circuit Serial Programming (ICSP) simplifies field updates, and debugging is supported through the MPLAB Snap and compatible AVR tools using two I/O pins plus reset.

Typical applications include industrial automation controllers, dual-channel serial communication gateways using the twin USARTs, and precision analog sensor acquisition via the 8-channel 10-bit ADC.

Design consideration: full 20 MHz operation requires a supply of 4.5V to 5.5V; lower-voltage operation derates the maximum safe clock frequency, so verify the frequency-versus-voltage curve before clocking down.

This page synthesizes distributor pricing, drop-in alternatives, pinout data, and practical design notes not found in the manufacturer datasheet.

드롭인 대체품: ATMEGA644P-20MQR — 동일 패키지, 핀 호환. PCB 재작업이 필요한 다른 패키지 부품은 제외됩니다.

이 시리즈의 변형

다음과 드롭인 호환되는 동일 시리즈 모델: ATMEGA644P-20MQR (동일 폼 팩터 및 풋프린트) — 차이점: Package, SRAM, Debug Interface, Throughput, EEPROM.

Microchip Technology
Package: 64-QFN (9x9 mm)
SRAM: 4 KB
Debug Interface: JTAG (on-chip debug)
비교 대상: ATMEGA644P-20MQR →
Microchip Technology
Package: 44-TQFP (10x10 mm)
SRAM: 4 KB
Debug Interface: JTAG (IEEE 1149.1) with on-chip debug
비교 대상: ATMEGA644P-20MQR →
Microchip Technology
Package: 44-VQFN (7x7 mm) with exposed pad
SRAM: 4 KB (4,096 bytes)
Throughput: Up to 20 MIPS (1 MIPS per MHz)
비교 대상: ATMEGA644P-20MQR →
Microchip Technology
Package: 44-pin TQFP (10x10 mm)
SRAM: 4 KB
비교 대상: ATMEGA644P-20MQR →

빠른 비교 도구 — 나란히 비교할 대체 부품을 선택하십시오:

ATMEGA644P-20MQ

✅ 드롭인
Microchip Technology
📦 44-VQFN (7x7 mm, MLF)
AVR 8-bit RISC · 20 MHz · Up to 20 MIPS (1 MIPS per MHz) · 64 KB (32K x 16) · 4 KB (4,096 bytes) · 2 KB (2,048 bytes) · 5 V · 32

✓ 재고 있음

$2.48 / 개

데이터시트 보기 →

ATMEGA644PA-MUR

✅ 드롭인
📦 44-VQFN (7x7 mm, MLF)
official successor (PA process): pin-compatible, same 20 MHz/64 KB/4 KB, lower power consumption; active lifecycle

📋 참조 대체품 (카탈로그에 없음)

ATMEGA644PA-AU

✅ 드롭인 ⚠️ 사양 미검증
Microchip Technology
📦 44-TQFP (10x10 mm)
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

✓ 재고 있음

$4.61 / 개

데이터시트 보기 →

ATMEGA64-16MI

✅ 드롭인 ⚠️ 사양 미검증
Microchip Technology
📦 44-VQFN (MLF)
AVR · 8-Bit · 16 MHz · 64 KB (32K x 16) · 4 KB · 2 KB · 10-bit · 8 channels

✓ 재고 있음

$4.48 / 개

데이터시트 보기 →

ATMEGA644-20AU

✅ 드롭인
Microchip Technology
📦 44-TQFP (10x10 mm)
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

✓ 재고 있음

$4.96 / 개

데이터시트 보기 →

ATMEGA644P-20MQR 최대 정격 & 전기적 특성

Core Processor AVR 8-bit RISC
Core Size 8-bit
Speed (Max Clock) 20 MHz
Flash Program Memory 64 KB (32K x 16)
SRAM 4 KB (4K x 8)
EEPROM 2 KB
Number of I/O 32
Supply Voltage (VCC) 4.5 V to 5.5 V (at 20 MHz)
Oscillator Type Internal
USART Count 2 (P variant dual USART)
Timers Two 8-bit, one 16-bit
ADC 8-channel, 10-bit
Communication Interfaces USART x2, SPI, TWI (I2C)
Debug Interface JTAG (on-chip debug, boundary scan)
Instruction Set 131 instructions, mostly single-cycle
Low Power Technology picoPower
동작 온도 -40C to +105C (extended, M grade)
패키지 / 케이스 44-VQFN (7x7 mm) exposed pad (MLF)
실장 유형 Surface Mount
Packaging Tape & Reel (TR)
RoHS / Green Status GREEN, RoHS compliant

ATMEGA644P-20MQR 핀 구성

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
핀 1 PA4 (ADC4) — Port A bit 4 / ADC input 4
핀 2 PA5 (ADC5) — Port A bit 5 / ADC input 5
핀 3 PA6 (ADC6) — Port A bit 6 / ADC input 6
핀 7 AREF — Analog reference for ADC
핀 8 PA3 (ADC3) — Port A bit 3 / ADC input 3
핀 9 PA2 (ADC2) — Port A bit 2 / ADC input 2
핀 10 PA1 (ADC1) — Port A bit 1 / ADC input 1
핀 11 PA0 (ADC0) — Port A bit 0 / ADC input 0
핀 14 PB0 (XCK0/T0) — Port B bit 0, USART0 external clock / Timer0
핀 15 PB1 (T1/CLKO) — Port B bit 1, Timer1 / clock output
핀 16 PB2 (AIN0/INT2) — Port B bit 2, analog comparator / external interrupt 2
핀 17 PB3 (AIN1/OC0A) — Port B bit 3, comparator / PWM output 0A
핀 18 PB4 (SS) — Port B bit 4, SPI slave select
핀 19 PB5 (MOSI) — Port B bit 5, SPI master output
핀 20 PB6 (MISO) — Port B bit 6, SPI master input
핀 21 PB7 (SCK) — Port B bit 7, SPI clock
핀 24 PC0 (SCL) — Port C bit 0, TWI clock
핀 25 PC1 (SDA) — Port C bit 1, TWI data
핀 26 PC2 (TCK) — Port C bit 2, JTAG test clock
핀 27 PC3 (TMS) — Port C bit 3, JTAG test mode select
핀 28 PC4 (TDO) — Port C bit 4, JTAG test data out
핀 29 PC5 (TDI) — Port C bit 5, JTAG test data in
핀 30 PC6 (TOSC1) — Port C bit 6, timer oscillator input
핀 31 PC7 (TOSC2) — Port C bit 7, timer oscillator output
핀 34 PD0 (RXD0) — Port D bit 0, USART0 receive
핀 35 PD1 (TXD0) — Port D bit 1, USART0 transmit
핀 36 PD2 (RXD1/INT0) — Port D bit 2, USART1 receive / interrupt 0
핀 37 PD3 (TXD1/INT1) — Port D bit 3, USART1 transmit / interrupt 1
핀 38 PD4 (XCK1/OC1B) — Port D bit 4, USART1 clock / PWM 1B
핀 39 PD5 (OC1A) — Port D bit 5, PWM output 1A
핀 40 PD6 (OC2A/ICP1) — Port D bit 6, PWM 2A / input capture
핀 41 PD7 (OC0B/RT0) — Port D bit 7, PWM 0B
핀 42 RESET — Active-low reset input
핀 43 XTAL1 — External clock / crystal input
핀 44 XTAL2 — Crystal output

일반적인 애플리케이션

ATMEGA644P-20MQR 적합 용도: 6 애플리케이션s: Industrial Automation Controllers, Dual-Channel Serial Communication Gateways, Analog Sensor Data Acquisition, Embedded Prototyping and Education Platforms, Appliance and Consumer Control Boards, Motor Control and Actuation Systems.

🏭

Industrial Automation Controllers

The ATMEGA644P-20MQR fits industrial control panels and programmable logic nodes because its extended -40C to +105C temperature rating and 4.5V to 5.5V 5V-tolerant supply match harsh factory-floor conditions where standard commercial parts fail. The 64 KB Flash accommodates state-machine and communication firmware with headroom for OTA-style field updates via ICSP, while 32 GPIO lines drive relays, read limit switches, and interface to HMI peripherals. The 8-channel 10-bit ADC digitizes thermistors and 4-20 mA-derived signals at up to 10-bit resolution, and JTAG enables on-chip debugging during commissioning. Placed on a 5V rail with 100 nF decoupling per supply pin, its single-cycle 20 MHz execution handles PID loops and sequential control with deterministic timing.

🌐

Dual-Channel Serial Communication Gateways

The dual USART of the ATmega644P 'P' variant is the defining feature for protocol gateways: one USART bridges an RS-485 Modbus network while the second services RS-232 diagnostics or a cellular module, all without software UART emulation overhead. Running at 20 MHz with single-cycle execution, the core sustains simultaneous baud rates up to 1 Mbps on both ports with error checking via frame and parity flags. The 44-VQFN (7x7 mm) package keeps the gateway PCB compact, and the extended -40C to +105C range suits unenclosed outdoor cabinets. The 4 KB SRAM buffers packet frames, and 2 KB EEPROM stores node addresses and configuration parameters through power cycles. Level shifters or transceivers on the USART pins complete a robust, self-contained bridge design.

🧩

Analog Sensor Data Acquisition

The integrated 8-channel 10-bit ADC makes the ATMEGA644P-20MQR a compact data-logger front end: up to eight sensor channels (temperature, humidity, pressure bridges, potentiometers) are multiplexed internally at up to 15 kSPS at full resolution. The AREF pin supports external precision references for improved absolute accuracy, and the internal bandgap option suits ratiometric measurements. With picoPower sleep modes, battery-powered loggers sample periodically at microamp-level sleep current, waking via timer interrupt. The 4 KB SRAM stores sample windows before block writes to external Flash over SPI, and 2 KB EEPROM retains calibration coefficients. The 7x7 mm VQFN with exposed pad grounds the analog die attach for low-noise operation, and the extended temperature rating supports outdoor and cold-chain monitoring hardware.

🔧

Embedded Prototyping and Education Platforms

The ATmega644P is a popular core for teaching and maker platforms (for example, Sanguino-class boards) because the AVR architecture is well documented, the 64 KB Flash removes size pressure during experimentation, and ICSP programming needs only four signal pins. The 32 GPIOs mapped across four 8-bit ports give students immediate access to buttons, LEDs, LCDs, and servo banks, while SPI and TWI host shields and sensors. The internal oscillator allows clock-less bring-up before an external 20 MHz crystal is fitted, and JTAG permits step-level debugging with standard AVR tools on one header. With 1 MIPS per MHz throughput, timing exercises behave predictably. The VQFN-44 package suits both custom two-layer student PCBs and pre-assembled trainer boards.

📺

Appliance and Consumer Control Boards

White-goods and appliance control boards benefit from the ATMEGA644P-20MQR's combination of 5V robustness, large 64 KB program space for multi-language UI and fault-logging firmware, and low-cost peripheral integration that eliminates external UART, EEPROM, and ADC chips. The 32 I/O lines drive seven-segment displays, relays, triac triggers, and touch or rotary inputs directly. The 2 KB EEPROM preserves user settings and cycle counters through mains interruptions, and the 10-bit ADC reads NTC thermistors and mains-sense dividers. The extended -40C to +105C rating covers unventilated motor compartments. Because the part is in tape-and-reel packaging, high-volume SMT lines feed it directly into pick-and-place, and the exposed-pad VQFN aids heat spreading within sealed enclosures.

⚙️

Motor Control and Actuation Systems

DC and stepper motor controllers exploit the ATMEGA644P-20MQR's one 16-bit timer (dual-slope PWM for precise speed control) plus two 8-bit timers for auxiliary PWM channels and scheduling. The 20 MHz single-cycle core executes FOC-lite or sensorless algorithms fast enough for small-motor applications, while the ADC samples current shunts and back-EMF. The 32 GPIOs drive gate drivers, H-bridge modules, and quadrature inputs, and external interrupts handle encoder counting. Operating from a 5V rail with the -40C to +105C grade, the controller survives enclosure heat near power stages; the exposed VQFN pad bonds to the PCB ground plane for thermal relief. JTAG on-chip debug lets engineers tune current-loop constants directly on the running motor hardware.

What is the ATMEGA644P-20MQR microcontroller?
The ATMEGA644P-20MQR is a Microchip AVR 8-bit RISC microcontroller with 64 KB Flash, 4 KB SRAM, 2 KB EEPROM, and 32 general-purpose I/O lines. It runs at up to 20 MHz from a 4.5V to 5.5V supply and comes in a 44-pin VQFN (7x7 mm) MLF package rated from -40C to +105C. According to the Microchip ATmega644P datasheet summary, it executes 131 instructions, most in a single clock cycle, delivering throughput close to 1 MIPS per MHz.
What is the maximum clock frequency of ATMEGA644P-20MQR?
The ATMEGA644P-20MQR supports a maximum clock frequency of 20 MHz, as indicated by the '20' speed code in its part number. This maximum speed is guaranteed only within the 4.5V to 5.5V operating supply range. At lower supply voltages, the safe maximum frequency is derated, so engineers must consult the maximum frequency versus supply voltage curve in the Microchip datasheet before operating the device below 4.5V.
How much memory does the ATMEGA644P-20MQR have?
The ATMEGA644P-20MQR contains 64 KB (32K x 16) of in-system programmable Flash program memory, 4 KB (4K x 8) of SRAM for data, and 2 KB of EEPROM for non-volatile parameter storage. According to DigiKey and the Microchip datasheet summary, the Flash supports In-Circuit Serial Programming (ICSP), allowing firmware updates without removing the chip from the board, and the EEPROM is byte-addressable for configuration data retention.
What is the difference between ATMEGA644P-20MQR and ATMEGA644P-20MQ?
The only difference is packaging: the ATMEGA644P-20MQR is supplied in Tape & Reel (TR) for automated production lines, while the ATMEGA644P-20MQ is supplied in a tray. Both share the identical die, 44-pin VQFN (7x7 mm) package, 20 MHz speed, 64 KB Flash, dual USARTs, and -40C to +105C extended temperature rating, making them functionally drop-in interchangeable on the same PCB footprint.
Can ATMEGA644PA replace ATMEGA644P-20MQR?
Yes, the ATmega644PA is Microchip's official replacement for the ATmega644P. According to the Microchip product page, the ATmega644P is a mature product not recommended for new designs and is replaced by the ATmega644PA. The PA variant is pin-compatible in the same 44-VQFN package, offers the same 64 KB Flash, 4 KB SRAM, and 20 MHz performance, but adds lower power consumption and is produced with a more modern process, making it the preferred choice for new designs and ongoing production.
What is the best drop-in replacement for ATMEGA644P-20MQR?
The best drop-in replacement is the ATMEGA644PA in the 44-VQFN (MLF) package, such as ATMEGA644PA-MUR. It is pin-to-pin compatible, uses the same footprint, and matches the 64 KB Flash, 4 KB SRAM, 2 KB EEPROM, and 20 MHz ratings while consuming less power. Microchip explicitly lists ATmega644PA as the successor on its product page. For same-die sourcing without redesign, the tray-packaged ATMEGA644P-20MQ is also fully interchangeable.
Why does the ATMEGA644P-20MQR have two USARTs and when does it matter?
The 'P' suffix in ATmega644P denotes the enhanced variant with a second USART, giving the device two independent full-duplex serial ports. According to the Microchip ATmega644P datasheet summary, this dual-USART capability is the principal architectural difference from the standard ATmega644. It matters in applications such as RS-485 gateways, GPS-to-display bridges, or debug logging alongside a production communication link, where two simultaneous serial channels would otherwise require software emulation or an external UART.
Is ATMEGA644P-20MQR RoHS compliant?
Yes, the ATMEGA644P-20MQR is a GREEN, RoHS-compliant part. According to the FindIC specification listing sourced from Microchip and Atmel product data, the device is described as 'QFN/MLF, EXT TEMP, GREEN, 5V, T&R', where GREEN denotes Microchip's RoHS-compliant, lead-free, halogen-free packaging designation. The tape-and-reel packaging and MLF finish are lead-free and suitable for standard reflow soldering profiles used in compliant assembly lines.
What is the operating temperature range of ATMEGA644P-20MQR?
The ATMEGA644P-20MQR is rated for the extended industrial temperature range of -40C to +105C. The 'M' temperature-grade code in the part number designates this extended range, as confirmed by the FindIC specification ('EXT TEMP'). This makes the part suitable for industrial environments, outdoor equipment, and other thermally demanding applications beyond the standard commercial 0C to +70C range of lesser grades.
How do I program the ATMEGA644P-20MQR in-circuit?
You program the ATMEGA644P-20MQR through In-Circuit Serial Programming (ICSP) using the SPI interface. According to the Microchip product page, tools such as the MPLAB SNAP connect to the target via an 8-pin SIL connector, using two device I/O pins and the reset line to implement in-circuit debugging and ICSP. The 64 KB Flash is programmable while soldered on the PCB, so reserve the MOSI, MISO, SCK, and RESET pins as accessible test points during PCB layout.
What is the price of ATMEGA644P-20MQR as of 2026-09-18?
As of 2026-09-18, the ATMEGA644P-20MQR is listed at approximately $6.36 per unit in single-piece quantity by Heisener (in stock), while LCSC lists it from $2.5307. Octopart compares bulk discounts from 6 distributors. On XAIPART, quantity price breaks are offered at 1, 10, 100, 500, and 1000 pieces, with the unit price decreasing at higher volumes. Always request a live quote for current availability and lead time.
Is ATMEGA644P-20MQR in stock and where can I buy it online?
Yes, the ATMEGA644P-20MQR is in stock at multiple distributors as of 2026-09-18. Heisener reports in stock at $6.3584 per unit, and LCSC lists it in stock from $2.5307. DigiKey also lists the part with shipping available. Octopart aggregates pricing from 6 distributors for comparison. You can order directly on XAIPART with tiered pricing, or compare across distributors using the Octopart listing for this MPN.
What is the lead time for ATMEGA644P-20MQR?
Lead time for the ATMEGA644P-20MQR is listed as 'to be confirmed' by some distributors such as Heisener, since Microchip has designated the ATmega644P as a mature product not recommended for new designs. Stocked inventory (for example, 5,056 pieces at Heisener and LCSC stock) can typically ship within days, while factory orders may face longer and less predictable lead times. For volume production, plan ahead and consider the ATMEGA644PA successor to secure long-term supply.
What is the best Microchip equivalent for ATMEGA644P-20MQR compared to other brands?
The best equivalent is Microchip's own ATMEGA644PA-MUR, the official successor with identical pinout and lower power. Cross-brand equivalents are scarce: no other manufacturer produces a pin-to-pin compatible AVR in the 44-VQFN footprint, and comparable parts such as Microchip PIC16 devices or other vendors' 8-bit MCUs use different pinouts and instruction sets, requiring firmware and PCB changes. For AVR architecture preservation, staying within Microchip's ATmega family is the recommended cross-reference path according to Microchip's cross-reference guidance.
What are the key specifications of ATMEGA644P-20MQR that engineers should know?
Engineers should know: AVR 8-bit RISC core at 20 MHz; 64 KB Flash (32K x 16), 4 KB SRAM, 2 KB EEPROM; 32 programmable I/O lines; two USARTs, SPI, TWI (I2C); 8-channel 10-bit ADC; two 8-bit and one 16-bit timers; JTAG debug; 4.5V to 5.5V supply; -40C to +105C extended temperature range; 44-pin VQFN (7x7 mm) exposed-pad package; picoPower low-power modes; and tape-and-reel packaging. According to the Microchip datasheet summary, throughput approaches 1 MIPS per MHz.
Where to download the ATMEGA644P-20MQR datasheet PDF and find the pinout?
The official ATmega644P datasheet summary PDF is available on Microchip's website at the DeviceDoc link (Atmel-42744-ATmega644P_Summary.pdf), and the full 64 KB-device complete datasheet can be downloaded from the ATmega644P product page at microchip.com. The 44-pin VQFN (MLF) pinout table, including PORTA through PORTD assignments, JTAG pins, and the exposed pad connection, is provided in the Pinout Configurations section of the datasheet. XAIPART also provides a pinout diagram on this product page.

엔지니어링 참조 데이터: ATMEGA644P-20MQR — 비교, 설계 지침 및 규정 준수 정보.

선택 가이드

Choose the ATMEGA644P-20MQR when you need a 20 MHz, 64 KB AVR with dual USARTs in the extended -40C to +105C range and the compact 7x7 mm VQFN footprint - ideal for industrial gateways and appliance controllers that already use this mature die. Choose ATMEGA644PA-MUR instead for all new designs: it is Microchip's official successor, pin-compatible in the same VQFN-44, with lower power and an active lifecycle. Choose ATMEGA644P-20MQ for identical silicon with tray packaging for pilot runs or mixed-volume assembly. Choose ATMEGA64-16MI if 16 MHz is sufficient and cost matters, accepting the classic-ATmega64 peripheral set. Choose TQFP-packaged variants (ATMEGA644PA-AU, ATMEGA644-20AU) only when hand-assembly or leaded inspection is required, noting the land-pattern change. Trade-off summary: 644P variants are proven but NRND; PA variants are future-safe; TQFP eases assembly but occupies more board area.

대체품과의 비교

파라미터 이 제품 ATMEGA644P-20MQ ATMEGA644PA-MUR ATMEGA644PA-AU ATMEGA64-16MI ATMEGA644-20AU
Package 44-VQFN (7x7 mm, MLF) exposed pad 44-VQFN (7x7 mm, MLF) - same 44-VQFN (7x7 mm, MLF) - same 44-TQFP (10x10 mm) - different footprint 44-VQFN (MLF) - same 44-TQFP (10x10 mm) - different footprint
Brand Microchip Technology (Atmel) Microchip Technology Microchip Technology Microchip Technology Microchip Technology Microchip Technology
Max Clock Frequency 20 MHz 20 MHz 20 MHz 20 MHz 16 MHz 20 MHz
Flash Program Memory 64 KB 64 KB 64 KB 64 KB 64 KB 64 KB
SRAM 4 KB 4 KB 4 KB 4 KB 4 KB 4 KB
USART Count 2 (dual, P variant) 2 2 2 2 1
Operating Temperature -40C to +105C (extended) -40C to +105C -40C to +105C -40C to +85C -40C to +105C -40C to +85C

주요 차별점

  • Dual USART for two simultaneous serial links (vs ATMEGA644-20AU)
  • Extended -40C to +105C temperature grade (vs ATMEGA644PA-AU)
  • Official active successor available with same footprint (vs ATMEGA644PA-MUR)

설계 노트

The ATMEGA644P-20MQR requires 4.5V to 5.5V for guaranteed 20 MHz operation; at 3.3V the safe maximum frequency is significantly lower per the frequency-versus-voltage curve in the datasheet. Estimated: a typical load of 32 GPIOs at 20 mA each plus core current of roughly 25 mA can draw over 600 mA, so size the 5V regulator accordingly and place 100 nF ceramic capacitors on every VCC pin with one 10 uF bulk capacitor at the board entry.

The 44-VQFN (MLF) package has an exposed die-attach pad on the underside that must be soldered to a ground-plane keepout array of thermal vias - it is the primary ground connection, not just thermal relief. Use a 3x3 or 4x4 via farm under the pad and a solder-paste stencil with about 50-70% coverage to avoid float during reflow. JTAG (PC2-PC5) and ICSP (PB5-PB7, RESET) should be routed to test points for programming and debug access.

Do not treat the ATmega644P as a long-term sourcing strategy: Microchip designates it a mature product not recommended for new designs, replaced by the ATmega644PA. For new layouts, design directly with ATMEGA644PA-MUR to secure future supply. Also note the second USART (PD2/PD3) exists only on 'P'-suffix parts - firmware written for it will fail silently on standard ATmega644 silicon, so verify the die variant at incoming inspection when dual-sourcing.

규정 준수 정보

RoHS
Compliant
REACH
Unknown
AEC-Q100
Not Applicable
무연
Yes
무할로겐
Yes
분쟁 광물
Unknown

Described as GREEN per Microchip/Atmel product data (FindIC listing), which denotes RoHS-compliant lead-free, halogen-free packaging. REACH and conflict-minerals status not stated in provided data.

데이터 검증일: 2026-09-18 — XAIPART 부품 엔지니어링 팀이 검증하고 관리한 데이터

관련 검색

ATMEGA644P-20MQR ATMEGA644P-20MQR datasheet PDF Microchip ATMEGA644P 20MHz 64KB microcontroller ATMEGA644P-20MQR 44-VQFN 7x7 MLF package ATmega644P dual USART microcontroller ATMEGA644P vs ATMEGA644PA difference ATMEGA644P-20MQR drop-in replacement ATMEGA644P-20MQR price buy in stock ATmega644P industrial controller 5V extended temperature what can replace ATMEGA644P-20MQR ATmega644P pinout 44 pin MLF 8-bit AVR microcontroller RS-485 gateway

관련 부품 & 용어

Microchip Technology Atmel ATMEGA644P-20MQR ATmega644P ATMEGA644PA-MUR ATMEGA644P-20MQ ATmega644 AVR 8-bit RISC microcontroller picoPower ICSP JTAG USART SPI TWI (I2C) 44-VQFN (MLF) TQFP-44 RoHS GREEN packaging MPLAB SNAP industrial automation RS-485 gateway 10-bit ADC extended temperature range
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