ATTINY861A-SUR

Overview

The ATTINY861A-SUR is an 8-bit AVR microcontroller featuring 8K bytes of In-System Programmable Flash, 512 bytes of EEPROM, and 512 bytes of SRAM. It operates at speeds up to 20 MHz with a throughput of 20 MIPS. The device supports a supply voltage range of 1.8V to 5.5V and includes 16 programmable I/O lines. Key peripherals include an 11-channel 10-bit ADC, an analog comparator, two timers/counters, and a Universal Serial Interface (USI). It utilizes a 32-pad MLF package.

Feature Summary

• Advanced RISC architecture executing most instructions in a single clock cycle for high efficiency.
• High endurance non-volatile memory segments with specified write/erase cycles and data retention capabilities.
• Integrated peripheral set including multi-channel ADC, analog comparator, and PWM outputs with dead time generation.
• Supports multiple low-power sleep modes and features an on-chip debug system.

Applications

• Configurable three-phase BLDC fan control applications
• General purpose embedded control systems requiring low power consumption
• Sensor interface circuits utilizing the integrated ADC and analog comparator

Procurement Notes

Verify the specific speed grade suffix matches the required operating frequency and voltage range. Confirm the MLF package variant aligns with PCB footprint requirements. Ensure the ordering code corresponds to the correct memory size within the ATtinyx61A family. Check for RoHS compliance status if mandated by project specifications.

Selection Notes

Select this component when 8K Flash and 512-byte RAM are required alongside extensive analog input channels. The MLF package suits compact surface-mount designs. Consider the 20 MHz maximum speed for processing-intensive tasks within the 1.8V to 5.5V operational window. Evaluate the USI interface compatibility against standard SPI or I2C master/slave needs.

Part Context

This part belongs to the ATtinyx61A series, which shares architectural similarities with the ATtiny261A and ATtiny461A. The primary distinction lies in the memory capacities, where the 861A variant offers the highest storage within this specific group. All variants utilize the same enhanced RISC core and peripheral configuration.

Replacement Considerations

ATtiny461A-SUR: Offers identical functionality with reduced memory capacity (4K Flash, 256B EEPROM/SRAM).

FAQ

What is the function of the center pad in the MLF package?

The center pad underneath the QFN/MLF package should be soldered to ground on the board to ensure mechanical stability.

How is AVCC connected if the ADC is not used?

AVCC should be externally connected to VCC even if some peripherals such as the ADC are not used.

What happens to the Stack Pointer during interrupt handling?

The return address Program Counter is stored on the Stack, which is allocated in the general data SRAM. The Stack Pointer must be initialized by software before interrupts are enabled.