ATMEGA645A-MUR Equivalent & Substitute Parts

Part Overview

The ATMEGA645A-MUR is an 8-bit AVR microcontroller manufactured by Microchip Technology, featuring 64KB of FLASH program memory, 4KB of RAM, and 2KB of EEPROM. This device operates at 16MHz with a supply voltage range of 1.8V to 5.5V and is housed in a 64-QFN (9x9) package with exposed pad. The part is currently in active production status and is ROHS3 compliant. Identifying equivalent substitute parts is necessary when the primary part number becomes unavailable or when alternative packaging configurations are required for specific manufacturing or inventory requirements.

Key Parameters

Parameter	Value
Core Processor	AVR
Core Size	8-Bit
Speed	16MHz
Program Memory Size	64KB (32K x 16)
Program Memory Type	FLASH
RAM Size	4K x 8
EEPROM Size	2K x 8
Voltage - Supply (Vcc/Vdd)	1.8V ~ 5.5V
Number of I/O	54
Data Converters	A/D 8x10b
Connectivity	SPI, UART/USART, USI
Peripherals	Brown-out Detect/Reset, POR, PWM, WDT
Operating Temperature	-40°C ~ 85°C (TA)
Package / Case	64-VFQFN Exposed Pad
Mounting Type	Surface Mount
RoHS Status	ROHS3 Compliant
Moisture Sensitivity Level (MSL)	3 (168 Hours)

Substitute Part Grouping Explanation

Substitution of the ATMEGA645A-MUR is determined by strict equivalence across the following critical parameters: core processor architecture (AVR), core size (8-Bit), clock speed (16MHz), program memory capacity (64KB FLASH), RAM capacity (4KB), EEPROM capacity (2KB), I/O count (54 pins), supply voltage range (1.8V ~ 5.5V), peripheral feature set (SPI, UART/USART, USI, Brown-out Detect/Reset, POR, PWM, WDT), data converter specifications (A/D 8x10b), and package type (64-QFN with exposed pad).

The ATMEGA645P-MU qualifies as a direct substitute based on identical electrical specifications and functional capabilities. The primary difference between these parts is the packaging configuration: ATMEGA645A-MUR is supplied in Tape & Reel (TR) format, while ATMEGA645P-MU is supplied in Tray format. Both parts share the same base product number (ATMEGA645), identical performance characteristics, and equivalent compliance certifications.

Parameter Comparison

Parameter	ATMEGA645A-MUR	ATMEGA645P-MU	Match
Manufacturer	Microchip Technology	Microchip Technology	Yes
Core Processor	AVR	AVR	Yes
Core Size	8-Bit	8-Bit	Yes
Speed	16MHz	16MHz	Yes
Program Memory Size	64KB (32K x 16)	64KB (32K x 16)	Yes
Program Memory Type	FLASH	FLASH	Yes
RAM Size	4K x 8	4K x 8	Yes
EEPROM Size	2K x 8	2K x 8	Yes
Voltage - Supply (Vcc/Vdd)	1.8V ~ 5.5V	1.8V ~ 5.5V	Yes
Number of I/O	54	54	Yes
Data Converters	A/D 8x10b	A/D 8x10b	Yes
Connectivity	SPI, UART/USART, USI	SPI, UART/USART, USI	Yes
Peripherals	Brown-out Detect/Reset, POR, PWM, WDT	Brown-out Detect/Reset, POR, PWM, WDT	Yes
Operating Temperature	-40°C ~ 85°C (TA)	-40°C ~ 85°C (TA)	Yes
Package / Case	64-VFQFN Exposed Pad	64-VFQFN Exposed Pad	Yes
Mounting Type	Surface Mount	Surface Mount	Yes
Supplier Device Package	64-QFN (9x9)	64-QFN (9x9)	Yes
RoHS Status	ROHS3 Compliant	ROHS3 Compliant	Yes
Moisture Sensitivity Level (MSL)	3 (168 Hours)	3 (168 Hours)	Yes
Product Status	Active	Active	Yes
Packaging Format	Tape & Reel (TR)	Tray	Different

Engineering Selection Recommendations

Both ATMEGA645A-MUR and ATMEGA645P-MU are active production parts from Microchip Technology with identical electrical and functional specifications. Selection between these parts should be based on packaging and supply chain requirements rather than technical performance.

ATMEGA645A-MUR in Tape & Reel format is suitable for high-volume automated assembly operations where continuous reel feeding is required. ATMEGA645P-MU in Tray format is appropriate for lower-volume production runs, manual assembly processes, or when tray-based component handling is preferred.

Both parts maintain ROHS3 compliance and identical moisture sensitivity specifications (MSL 3, 168 Hours), ensuring equivalent handling and storage requirements. The choice between these substitutes does not impact circuit design, firmware compatibility, or functional performance.

Frequently Asked Questions (FAQ)

Q: Are ATMEGA645A-MUR and ATMEGA645P-MU electrically identical?

A: Yes. Both parts share identical core processor architecture, clock speed, memory configuration (64KB FLASH, 4KB RAM, 2KB EEPROM), I/O count, peripheral features, and operating specifications. They are functionally equivalent at the circuit and firmware level.

Q: What is the difference between Tape & Reel and Tray packaging?

A: Tape & Reel (TR) packaging supplies components on a continuous reel suitable for automated pick-and-place assembly equipment. Tray packaging supplies components in static-dissipative trays suitable for manual handling or lower-volume assembly processes. The physical component itself is identical.

Q: Can I use ATMEGA645P-MU as a direct replacement for ATMEGA645A-MUR in my design?

A: Yes, provided your assembly process can accommodate tray-format components. No circuit modifications, PCB layout changes, or firmware updates are required. Pin configuration, electrical characteristics, and functional behavior are identical.

Q: Are there any compliance or certification differences between these parts?

A: No. Both parts carry identical ROHS3 compliance status, REACH unaffected designation, and moisture sensitivity level (MSL 3). Storage and handling requirements are equivalent.

Q: What should I consider when selecting between these substitute parts?

A: Base your selection on manufacturing process requirements. Choose Tape & Reel format for high-volume automated assembly. Choose Tray format for lower-volume production, manual assembly, or when your equipment is configured for tray-based component feeding.

Request Quote (Ships tomorrow)

Part Number

Quantity

Company

Contact Name

E-mail

Message