Microchip Technology ATmega328 8-Bit AVR MCUs

Microchip Technology ATmega328 8-Bit AVR MCUs are low-power, CMOS 8-bit microcontrollers based on the AVR® enhanced RISC architecture. The devices execute instructions in a single clock cycle to achieve CPU throughput approaching one million instructions per second (MIPS) per megahertz. This allows for optimizing power consumption versus processing speed.


  • High performance, low power AVR® 8-Bit Microcontroller family
  • Advanced RISC architecture
    • 131 powerful instructions – most single clock cycle execution
    • 32 x 8 general-purpose working registers
    • Fully static operation
    • Up to 20 MIPS throughput at 20MHz
    • On-chip 2-cycle multiplier
  • High endurance non-volatile memory segments
    • 4/8/16/32KBytes of in-system self-programmable Flash program memory
    • 256/512/512/1KBytes EEPROM
    • 512/1K/1K/2KBytes internal SRAM
    • Write/erase cycles 10,000 Flash/100,000 EEPROM
    • Data retention 20 years at 85°C/100 years at 25°C(1)
    • Optional boot code section with independent lock bits
  • In-system programming by an on-chip boot program
  • True read-while-write operation
    • Programming lock for software security
  • QTouch® library support
    • Capacitive touch buttons, sliders, and wheels
    • QTouch and QMatrix™ acquisition
    • Up to 64 sense channels
  • Peripheral features
    • Two 8-bit timer/counters with separate prescaler and compare mode
    • One 16-bit timer/counter with separate prescaler, compare mode, and capture mode
  • Real-time counter with separate oscillator
    • Six PWM channels
    • 8-channel 10-bit ADC in TQFP and VQFN package
  • Temperature measurement
    • 6-channel 10-bit ADC in SPDIP package
  • Temperature measurement
    • Programmable serial USART
    • Master/slave SPI serial interface
    • Byte-oriented 2-wire serial interface (Philips I2C compatible)
    • Programmable watchdog timer with separate on-chip oscillator
    • On-chip analog comparator
    • Interrupt and wake up on Pin change
  • Special microcontroller features
    • Power-on reset and programmable brown-out detection
    • Internal calibrated oscillator
    • External and internal interrupt sources
    •  Six sleep modes: Idle, ADC Noise Reduction, Power-save, Power-down, Standby, and Extended Standby
  • I/O and packages
    • 23 programmable I/O lines
    • 28-pin SPDIP, 32-lead TQFP, 28-pad VQFN, and 32-pad VQFN
  • Operating voltage
    • 1.8 - 5.5V
  • Temperature range
    • -40°C to 85°C
  • Speed grade
    • 0-4MHz at 1.8-5.5V, 0-10MHz at 2.7-5.5.V, 0-20MHz at 4.5-5.5V
  • Power consumption at 1MHz, 1.8V, 25°C
    • Active mode 0.2mA
    • Power-down mode 0.1µA
  • Power-save mode 0.75µA (including 32kHz RTC)


  • Home and building automation
  • Comfort and control
  • Industrial automation
  • Sensors

Block Diagram

Block Diagram - Microchip Technology ATmega328 8-Bit AVR MCUs
Published: 2011-05-18 | Updated: 2023-09-13