Overview
The ATmega48PA/88PA/168PA/328P is a low-power CMOS 8-bit microcontroller based on the AVR enhanced RISC architecture. By executing powerful instructions in a single clock cycle, the ATmega48PA/88PA/168PA/328P achieves throughputs approaching 1 MIPS per MHz allowing the system designer to optimize power consumption versus processing speed.

Features
• High Performance, Low Power AVR® 8-Bit Microcontroller
• 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 20 MHz
   – On-chip 2-cycle Multiplier
• High Endurance Non-volatile Memory Segments
   – 4/8/16/32K Bytes of In-System Self-Programmable Flash progam memory
      (ATmega48PA/88PA/168PA/328P)
   – 256/512/512/1K Bytes EEPROM (ATmega48PA/88PA/168PA/328P)
   – 512/1K/1K/2K Bytes Internal SRAM (ATmega48PA/88PA/168PA/328P)
   – 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 On-chip Boot Program
      True Read-While-Write Operation
   – Programming Lock for Software Security
• 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 QFN/MLF package
      Temperature Measurement
   – 6-channel 10-bit ADC in PDIP 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 PDIP, 32-lead TQFP, 28-pad QFN/MLF and 32-pad QFN/MLF
• Operating Voltage:
   – 1.8 - 5.5V for ATmega48PA/88PA/168PA/328P
• Temperature Range:
   – -40°C to 85°C
• Speed Grade:
   – 0 - 20 MHz @ 1.8 - 5.5V
• Low Power Consumption at 1 MHz, 1.8V, 25°C for ATmega48PA/88PA/168PA/328P:
   – Active Mode: 0.2 mA
   – Power-down Mode: 0.1 µA
   – Power-save Mode: 0.75 µA (Including 32 kHz RTC)