Features High Performance, Low Power AVR 8-Bit Microcontroller Advanced RISC Architecture 123 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 High Endurance Non-volatile Memory Segments 2/4/8K Bytes of In-System Self-Programmable Flash Program Memory 8-bit Endurance: 10,000 Write/Erase Cycles 128/256/512 Bytes of In-System Programmable EEPROM Microcontroller Endurance: 100,000 Write/Erase Cycles 128/256/512 Bytes of Internal SRAM with 2/4/8K Data retention: 20 Years at 85C / 100 Years at 25C In-System Programmable via SPI Port Bytes In-System Programming Lock for Software Security Peripheral Features Programmable One 8/16-bit Timer/Counter with Prescaler One 8/10-bit High Speed Timer/Counter with Prescaler Flash 3 High Frequency PWM Outputs with Separate Output Compare Registers Programmable Dead Time Generator 10-bit ADC ATtiny261A 11 Single-Ended Channels 16 Differential ADC Channel Pairs ATtiny461A 15 Differential ADC Channel Pairs with Programmable Gain (1x, 8x, 20x, 32x) On-Chip Analog Comparator ATtiny861A Programmable Watchdog Timer with Separate On-Chip Oscillator Universal Serial Interface with Start Condition Detector 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 Four Sleep Modes: Low Power Idle, ADC Noise Reduction, Standby and Power- Down On-Chip Temperature Sensor I/O and Packages 16 Programmable I/O Lines 20-pin PDIP, 20-pin SOIC, 20-pin TSSOP and 32-pad MLF Operating Voltage 1.8 5.5V Speed Grades 0 4 MHz 1.8 5.5V 0 10 MHz 2.7 5.5V 0 20 MHz 4.5 5.5V Power Consumption at 1 MHz, 1.8V, 25C Active: 200 A Power-Down Mode: 0.1 A 8197CAVR05/111. Pin Configurations Figure 1-1. Pinout ATtiny261A/461A/861A PDIP/SOIC/TSSOP (MOSI/DI/SDA/OC1A/PCINT8) PB0 1 20 PA0 (ADC0/DI/SDA/PCINT0) (MISO/DO/OC1A/PCINT9) PB1 2 19 PA1 (ADC1/DO/PCINT1) (SCK/USCK/SCL/OC1B/PCINT10) PB2 3 18 PA2 (ADC2/INT1/USCK/SCL/PCINT2) (OC1B/PCINT11) PB3 4 17 PA3 (AREF/PCINT3) VCC 5 16 AGND GND 6 15 AVCC (ADC7/OC1D/CLKI/XTAL1/PCINT12) PB4 7 14 PA4 (ADC3/ICP0/PCINT4) (ADC8/OC1D/CLKO/XTAL2/PCINT13) PB5 8 13 PA5 (ADC4/AIN2/PCINT5) (ADC9/INT0/T0/PCINT14) PB6 9 12 PA6 (ADC5/AIN0/PCINT6) (ADC10/RESET/PCINT15) PB7 10 11 PA7 (ADC6/AIN1/PCINT7) NC NC 1 24 (OC1B/PCINT11) PB3 23 PA2 (ADC2/INT1/USCK/SCL/PCINT2) 2 PA3 (AREF/PCINT3) NC 3 22 VCC 21 AGND 4 QFN/MLF NC GND 5 20 NC 19 NC 6 AVCC (ADC7/OC1D/CLKI/XTAL1/PCINT12) PB4 7 18 (ADC8/OC1D/CLKO/XTAL2/PCINT13) PB5 17 PA4 (ADC3/ICP0/PCINT4) 8 Note: To ensure mechanical stability the center pad underneath the QFN/MLF package should be soldered to ground on the board. 2 ATtiny261A/461A/861A 8197CAVR05/11 PB2 (SCK/USCK/SCL/OC1B/PCINT10) 9 32 NC PB1 (MISO/DO/OC1A/PCINT9) (ADC9/INT0/T0/PCINT14) PB6 10 31 PB0 (MOSI/DI/SDA/OC1A/PCINT8) 11 30 (ADC10/RESET/PCINT15) PB7 NC NC 12 29 13 28 NC (ADC6/AIN1/PCINT7) PA7 NC (ADC5/AIN0/PCINT6) PA6 14 27 15 26 PA0 (ADC0/DI/SDA/PCINT0) (ADC4/AIN2/PCINT5) PA5 PA1 (ADC1/DO/PCINT1) NC 16 25