Overview
The Atmel ATmega48/88/168 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 ATmega48/88/168 achieves throughputs approaching 1 MIPS per MHz allowing the system designer to optimize power consumption versus processing speed.

Features
• High performance, low power Atmel® AVR® 8-bit microcontroller
• Advanced RISC architecture
   – 131 powerful instructions – most single clock cycle execution
   – 32 × 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 Kbytes of in-system self-programmable flash program memory
   – 256/512/512 bytes EEPROM
   – 512/1K/1Kbytes internal SRAM
   – Write/erase cyles: 10,000 flash/100,000 EEPROM
   – Data retention: 20 years at 85°C/100 years at 25°C()
   – 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
• 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 QFN/MLF package
   – 6-channel 10-bit ADC in PDIP Package
   – 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
   – DebugWIRE on-chip debug system
   – Power-on reset and programmable brown-out detection
   – Internal calibrated oscillator
   – External and internal interrupt sources
   – Five sleep modes: Idle, ADC noise reduction, power-save, power-down, and 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:
   – 1.8V - 5.5V for Atmel ATmega48V/88V/168V
   – 2.7V - 5.5V for Atmel ATmega48/88/168
• Temperature range:
   – -40°C to 85°C
• Speed grade:
   – ATmega48V/88V/168V: 0 - 4MHz @ 1.8V - 5.5V, 0 - 10MHz @ 2.7V - 5.5V
   – ATmega48/88/168: 0 - 10MHz @ 2.7V - 5.5V, 0 - 20MHz @ 4.5V - 5.5V
• Low power consumption
   – Active mode:
      250µA at 1MHz, 1.8V
      15µA at 32kHz, 1.8V (including oscillator)
   – Power-down mode:
      0.1µA at 1.8V