ATMEGA649A-MU

ATMEGA649A-MU is an 8-bit AVR microcontroller from Atmel (Microchip) in the megaAVR family, packaged in a 44-pin MU TQFP.
- Core and memory: AVR RISC core, up to about 16 MIPS at 16 MHz; 64 KB flash, 4 KB RAM, 2 KB EEPROM.
- Peripherals: three Timer/Counters (8/16-bit), USART, SPI, I2C (TWI), 8-channel 10-bit ADC, analog comparator, watchdog, and brown-out detection.
- Power/clock: operating voltage typically 1.8–5.5 V; up to 20 MHz at higher voltages.
- I/O and features: rich interrupt system, in-system programmable via ISP, multiple sleep modes for low power.
- Package: slim surface-mount MU 44-pin package.
- Development: supported by Microchip Studio/Atmel Studio and the standard AVR toolchain.
Typical uses include mid-range embedded controllers, data acquisition, instrumentation, and motor control. For exact memory sizes and feature details, refer to the latest datasheet.

Direct one-to-one non-Atmel equivalents don’t exist. Closest Microchip/Atmel megaAVR substitutes by pin/feature:
- ATmega640, ATmega644A, ATmega645A (same 64K flash family; similar RAM/EEPROM)
- ATmega649, ATmega649A (same memory footprint; different packaging)
- ATmega1284P (more flash/RAM if higher capacity is acceptable)
Packaging: MU, PU, AU denote different packages (QFP, DIP, etc.) of these devices.

ATMEGA649A-MU features (concise):
- AVR 8-bit RISC CPU, up to 20 MIPS at 20 MHz
- 64 KB Flash program memory with In-System Programming and boot loader support
- 4 KB SRAM and 2 KB EEPROM
- 32 I/O lines (general-purpose I/O)
- 8-channel, 10-bit ADC
- Four timers/counters (8/16-bit) with PWM outputs
- Serial interfaces: USART, SPI, and I2C (TWI)
- JTAG and/or DebugWIRE for on-chip debugging
- Watchdog timer and Brown-out Detector
- Comprehensive interrupt system with multiple sources
- Operating voltage: 2.7–5.5V; compatible in a 40-pin MU package
Note: exact memory sizes and peripheral counts can vary slightly by revision; this reflects the common key specifications of the ATmega649A family.

- Pin count: 100 pins (MU = 100-pin μQFP/TQFP package)
- Function: ATmega649A-MU is an 8-bit AVR microcontroller with on‑chip flash, RAM, and EEPROM plus peripherals (USART, SPI, I2C/TWI, ADC, timers/PWM) for embedded control applications.

Manufacturer: Microchip Technology Inc. (the ATmega AVR line originated with Atmel and was acquired by Microchip in 2016).
What kind of company: An American multinational semiconductor company that designs, develops, and manufactures microcontrollers (AVR and PIC), memory, and analog/mixed-signal ICs.

ATmega649A-MU is a low‑power 8‑bit AVR MCU with 64 KB flash, I/O, ADC, timers, PWM, and serial interfaces (UART/SPI/I2C). Common application areas:
- Consumer electronics and appliances (remote controls, meters, displays)
- Automotive electronics (body/controllers, sensor interfaces)
- Industrial automation and instrumentation (sensor nodes, data logging, small PLC tasks)
- Motor control for small DC/stepper motors
- Data logging and handheld instruments
- Home/building automation and IoT devices (thermostats, lighting, security)
- Education, prototyping and hobby projects

MU indicates a 100-pin LQFP/Thin Quad Flat Pack package. So ATMEGA649A-MU comes in a 100‑pin LQFP (TQFP) package.