Overview
ATtiny40 is a low-power CMOS 8-bit microcontroller based on the compact AVR enhanced RISC architecture. By executing powerful instructions in a single clock cycle, the ATtiny40 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
   – 54 Powerful Instructions – Most Single Clock Cycle Execution
   – 16 x 8 General Purpose Working Registers
   – Fully Static Operation
   – Up to 12 MIPS Throughput at 12 MHz
• Non-volatile Program and Data Memories
   – 4K Bytes of In-System Programmable Flash Program Memory
   – 256 Bytes Internal SRAM
   – Flash Write/Erase Cycles: 10,000
   – Data Retention: 20 Years at 85oC / 100 Years at 25oC
• Peripheral Features
   – One 8-bit Timer/Counter with Two PWM Channels
   – One 8/16-bit Timer/Counter
   – 10-bit Analog to Digital Converter
• 12 Single-Ended Channels
   – Programmable Watchdog Timer with Separate On-chip Oscillator
   – On-chip Analog Comparator
   – Master/Slave SPI Serial Interface
   – Slave TWI Serial Interface
• Special Microcontroller Features
   – In-System Programmable
   – External and Internal Interrupt Sources
   – Low Power Idle, ADC Noise Reduction, Stand-by and Power-down Modes
   – Enhanced Power-on Reset Circuit
   – Internal Calibrated Oscillator
• I/O and Packages
   – 20-pin SOIC/TSSOP: 18 Programmable I/O Lines
   – 20-pad VQFN/MLF: 18 Programmable I/O Lines
• Operating Voltage:
   – 1.8 – 5.5V
• Programming Voltage:
   – 5V
• Speed Grade
   – 0 – 4 MHz @ 1.8 – 5.5V
   – 0 – 8 MHz @ 2.7 – 5.5V
   – 0 – 12 MHz @ 4.5 – 5.5V
• Industrial Temperature Range
• Low Power Consumption
   – Active Mode:
• 200 µA at 1 MHz and 1.8V
   – Idle Mode:
• 25 µA at 1 MHz and 1.8V
   – Power-down Mode:
• < 0.1 µA at 1.8V