ATtiny261/461/861 is a high performance, low power AVR® 8-Bit Microcontroller from Atmel.
The ATtiny261/461/861 family are low‑power 8‑bit AVR microcontrollers featuring 2/4/8 KB of in‑system programmable flash, up to 512 B of EEPROM and SRAM, and a rich set of peripherals including multiple timers, a 10‑bit ADC, and a universal serial interface. They operate from 1.8 V to 5.5 V (V‑rated versions) and offer speed grades up to 20 MHz.
The document includes pin‑out diagrams, block diagrams of the AVR core, detailed descriptions of I/O ports, power‑saving modes, and packaging options (20‑pin PDIP, SOIC, and 32‑pad QFN/MLF). It also references development tools and code examples for using the device.
| Flash Memory | 2 KB / 4 KB / 8 KB |
|---|---|
| EEPROM | 128 B / 256 B / 512 B |
| SRAM | 128 B / 256 B / 512 B |
| Operating Voltage | 1.8 V‑5.5 V (V‑rated), 2.7 V‑5.5 V (non‑V) |
| Maximum Clock Frequency | 4 MHz @ 1.8 V, 10 MHz @ 2.7 V, 20 MHz @ 4.5 V |
| Active Mode Current | 380 µA at 1 MHz, 1.8 V |
| Power‑down Mode Current | 0.11 µA at 1.8 V |
| ADC | 10‑bit, 11 single‑ended channels, 16 differential pairs |
| Timers | 8/16‑bit Timer/Counter with PWM, 8/10‑bit High‑Speed Timer/Counter |
| I/O Pins | 16 programmable I/O lines |
| Package Types | 20‑pin PDIP, 20‑pin SOIC, 32‑pad QFN/MLF |
The V‑rated versions operate from 1.8 V to 5.5 V, while the non‑V versions operate from 2.7 V to 5.5 V.
Depending on the specific model, the devices provide 2 KB, 4 KB, or 8 KB of in‑system programmable flash memory.
The active‑mode current is 380 µA under those conditions.
The microcontroller offers 16 programmable I/O lines.