Microchip ATTINY45-20SUR: A Comprehensive Datasheet Overview and Application Guide

The Microchip ATTINY45-20SUR stands as a testament to the power and versatility packed into minimal form factors. As a high-performance, low-power 8-bit AVR RISC-based microcontroller, it is a cornerstone for countless compact and efficient embedded designs. This article provides a detailed overview of its key features and a practical guide for its application.

Core Architectural Overview

At its heart, the ATTINY45-20SUR is built on the proven AVR enhanced RISC architecture. It can execute most instructions in a single clock cycle, achieving a throughput approaching 1 MIPS per MHz, allowing the system to optimize power consumption versus processing speed. The chip operates at a maximum of 20 MHz under a 4.5V to 5.5V supply, as denoted by the "-20" in its part number. The "SUR" suffix indicates it is supplied in an 8-pin SOIC package, ideal for space-constrained applications.

Its core specifications include:

4 KB of In-System Programmable Flash Memory: For storing application code.

256 Bytes of EEPROM: For storing long-term data that must persist without power.

256 Bytes of SRAM: For data manipulation during runtime.

6 General Purpose I/O Lines: Highly versatile pins that can be reconfigured for various purposes.

Key Features and Peripherals

Despite its small size, the ATTINY45-20SUR is rich with integrated peripherals that reduce external component count and total system cost.

Advanced Analog Capabilities: It includes a 10-bit ADC (Analog-to-Digital Converter) with 4 single-ended channels, enabling it to read sensors for temperature, light, or potentiometer values.

Timers/Counters: Two 8-bit timers/counters with separate prescalers and compare modes, plus one high-speed 8-bit timer with PWM. These are essential for generating precise timing signals, waveforms (PWM for motor control or LED dimming), and measuring external events.

Internal Oscillators: Features built-in calibrated oscillators of 8 MHz and 128 kHz, eliminating the need for an external crystal in many applications and further saving board space and cost.

Universal Serial Interface (USI): A highly flexible peripheral that can be configured to function as an I2C, SPI, or TWI master/slave, facilitating communication with other chips and sensors.

Robust On-Chip Debugging: DebugWIRE support allows for easy on-chip debugging, streamlining the development process.

Application Guide and Design Considerations

The ATTINY45-20SUR excels in a vast array of applications, including but not limited to:

Sensor Nodes: Its analog capabilities and low-power modes make it perfect for reading and processing data from various environmental sensors.

PC Peripherals: HIDs like keyboards, mice, and game controllers.

Appliance Control: Managing logic in small home appliances thanks to its small size and sufficient I/O.

LED Lighting and Dimming Control: Utilizing its fast PWM outputs.

Battery-Powered Devices: Its multiple sleep modes (Idle, ADC Noise Reduction, Standby, and Power-down) are crucial for maximizing battery life.

When designing with this microcontroller, consider the following:

1. Power Management: Leverage the sleep modes aggressively. Put the CPU to sleep when idle and use interrupts to wake it up for tasks.

2. Pin Planning: With only 6 I/O pins, planning is critical. Use the USI for communication to free up pins for other functions.

3. Programming: The chip is typically programmed via the SPI-based In-System Programming (ISP) interface using tools like the AVRISP mkII or cheaper USBasp programmers.

ICGOODFIND Summary

The Microchip ATTINY45-20SUR is an immensely powerful and cost-effective microcontroller that proves immense functionality can be delivered in an extremely small package. Its blend of processing efficiency, rich integrated peripherals (like ADC and USI), and excellent low-power characteristics make it an ideal choice for compact, intelligent designs across consumer, industrial, and hobbyist markets. For engineers and makers looking to minimize footprint and cost without sacrificing capability, the ATTINY45 remains a top contender.

Keywords: AVR Microcontroller, Low-Power Design, Embedded Systems, Peripheral Integration, ATTINY45