Part Number: ATtiny25-20SSUR

Manufacturer: Microchip Technology

Description: IC MCU 8BIT 2KB FLASH 8SOIC

Shipped from: Shenzhen/HK Warehouse

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Technical Specifications of ATTINY25-20SSUR

Datasheet  ATTINY25-20SSUR datasheet
Category Integrated Circuits (ICs)
Family Embedded – Microcontrollers
Manufacturer Atmel
Series AVR? ATtiny
Packaging Tape & Reel (TR)
Part Status Active
Core Processor AVR
Core Size 8-Bit
Speed 20MHz
Connectivity USI
Peripherals Brown-out Detect/Reset, POR, PWM, WDT
Number of I/O 6
Program Memory Size 2KB (1K x 16)
Program Memory Type FLASH
EEPROM Size 128 x 8
RAM Size 128 x 8
Voltage – Supply (Vcc/Vdd) 2.7 V ~ 5.5 V
Data Converters A/D 4x10b
Oscillator Type Internal
Operating Temperature -40°C ~ 85°C (TA)
Package / Case 8-SOIC (0.154″, 3.90mm Width)
Supplier Device Package 8-SOIC


With the ATtiny25/45/85 series, you can unlock the secret potential of microcontrollers. The AVR-enhanced RISC architecture makes this series a marvel of efficiency and low power use. Whether you’re an expert in electronics or new to the world of microcontrollers, this complete guide will help you find out what these 8-bit wonders can really do. Prepare to learn about the most important features, how to program, and the wide range of jobs that these tiny powerhouses are great at. Prepare to go on a trip that will teach you everything you need to know to make the most of the ATtiny25/45/85 microcontrollers. There are a lot of things you could do, and the future of creation is in your hands.

Overview of the ATtiny25/45/85

The ATtiny25/45/85 line of low-power CMOS 8-bit microcontrollers was created by Atmel, which is now a division of Microchip Technology. These little, potent devices are made to handle a variety of applications that need to strike a compromise between performance and power usage. Let’s look at the salient characteristics that set them apart:

● 8-bit Low-Power CMOS Microcontrollers

The AVR family of microcontrollers, recognized for their low-power operation and effective instruction execution, includes the ATtiny25/45/85 series. These microcontrollers are made to operate with the least amount of power possible, which makes them perfect for battery-operated and energy-conscious applications.

● Enhanced RISC architecture for AVR

The ATtiny25/45/85’s core processor is an AVR (Advanced Virtual RISC) improved RISC architecture. Reduced Instruction Set Computing, or RISC, refers to the microcontroller’s use of a streamlined instruction set with an emphasis on completing operations in a limited number of clock cycles. The microcontroller’s performance is optimized by this architecture, allowing it to process several instructions in a single clock cycle and achieve high throughput.

● Single Clock Cycle Execution

The ATtiny25/45/85 microcontrollers’ prowess in carrying out heavy commands in a single clock cycle is one of their main advantages. This feature, which enables the microcontroller to carry out complicated operations quickly, is essential for obtaining faster processing speeds. The microcontroller uses less power since fewer clock cycles are required to perform instructions, making it a great option for battery-operated and power-sensitive applications.

● 32 General-Purpose Working Registers with a Rich Instruction Set

The extensive and adaptable instruction set of the ATtiny25/45/85 microcontrollers offers a variety of functionality. With the least amount of code and processing time, these instructions enable programmers to effectively implement a variety of functions, including data manipulation, control flow, and arithmetic operations.

A notable advantage is the availability of 32 general-purpose working registers. Due to their direct connection to the microcontroller’s Arithmetic Logic Unit (ALU), these registers allow for the simultaneous access of two independent registers during a single clock cycle. Compared to Complex Instruction Set Computing (CISC) microcontrollers, where instructions may require numerous clock cycles to execute, this improves code efficiency and leads to speedier performance.

Features of the ATtiny25/45/85 Microcontrollers

The ATtiny25/45/85 microcontrollers offer a variety of memory choices for storing data and programs.

These microcontrollers have in-system programmable flash memory with a capacity of 2/4/8K bytes. The Flash memory enables quick upgrades and alterations without the requirement for physical chip replacement by allowing users to modify the microcontroller’s code in-circuit.

The devices have 128/256/512 bytes of EEPROM (Electrically Erasable Programmable Read-Only Memory) memory. Since EEPROM is non-volatile memory, it keeps its data even after the power is turned off. This qualifies it for the storage of crucial calibration values, setup data, and user settings.

  • SRAM (Static Random-Access Memory): The 128/256/256 bytes of SRAM on the ATtiny25/45/85 microcontrollers are used to store variables and data while programs are running. SRAM is volatile memory, which means that when the power is switched off, its contents are lost.
  • Six general-purpose I/O (GPIO) lines are available on these microcontrollers, and they can be set up as inputs or outputs. With the help of these pins, the microcontroller may connect to various peripherals and external devices, including sensors, displays, switches, and communication modules. Users can modify the microcontroller to fit a variety of applications thanks to GPIO flexibility.
  • Timer/Counters: The ATtiny25/45/85 microcontrollers come with an 8-bit timer/counter and a high-speed timer/counter. These add-ons are essential for keeping track of time, creating exact delays, and tracking outside occurrences. The high-speed Timer/Counter can handle more stringent timing needs, while the 8-bit Timer/Counter is adequate for basic timing jobs.
  • Comparing Control Modes for Precision: The microcontroller can generate precise timing events and precisely control external devices thanks to the comparison modes of the Timer/Counters. The microcontroller may initiate specified actions or interrupt by comparing the Timer/Counter value with predefined threshold values, which makes it a crucial component of real-time applications and event-driven programming.
  • USI, or Universal Serial Interface: The Universal Serial Interface (USI) on the ATtiny25/45/85 microcontrollers supports a number of different communication protocols, including SPI (Serial Peripheral Interface) and I2C (Inter-Integrated Circuit). The microcontroller can interface with other devices like sensors, displays, and memory chips thanks to the USI, making it possible for easy integration into complicated systems.

The microcontrollers are capable of handling both internal and external interrupts. Specific microcontroller events, such as Timer/Counter overflows or ADC conversions, might cause internal interrupts. Conversely, external signals supplied to certain pins cause external interruptions to occur. The microcontroller can respond fast to important events thanks to interrupts, enabling more effective and event-driven programming.

The 4-channel, 10-bit Analog-to-Digital Converter (ADC) is a feature of the ATtiny25/45/85 microcontrollers. The ADC enables the microcontroller to measure and digitize analog signals from sensors, potentiometers, and other analog devices. Reading analog input from the real world and using the converted values to make decisions that are well-informed depend on this capacity.

Programmable Watchdog Timer: The microcontrollers have a Watchdog Timer (WDT) that may be customized to increase system security and dependability. If the microcontroller becomes unresponsive or changes states unexpectedly, the WDT is intended to reset it. It acts as a failsafe device, making sure the microcontroller keeps working properly even under unforeseen circumstances.

The following three software-selectable power-saving modes: Three power-saving modes are available on the ATtiny25/45/85 microcontrollers:

  • Idle Mode: The CPU is turned down in this mode, but the SRAM, Timer/Counter, ADC, and Interrupt systems are still active. This setting enables speedy wake-up and responsiveness while reducing power usage.
  • Power-down Mode: In this mode, the microcontroller turns off all chip operations while preserving the contents of the registers. The only two ways to wake up the microcontroller are via interrupt or hardware reset. When a system must be left inactive for a long time to save power, power-down mode is the best option.
  • ADC Noise Reduction Mode: During analog-to-digital conversions, this mode disables the CPU and all other I/O modules except the ADC. It improves the accuracy of analog measurements while saving power by reducing switching noise during ADC operations.


Microcontrollers like the ATtiny25/45/85 perform well in a wide variety of applications because they are versatile and power-efficient. IoT devices, wearable technology, sensor interfaces, consumer electronics, industrial automation, automotive systems, educational technology, and security systems are a few examples. They are an appealing option for a variety of tasks in the real world because of their small size, low power consumption, and rich feature sets.


In conclusion, the ATtiny25/45/85 microcontrollers represent a compelling and efficient solution for a wide range of embedded systems and electronics projects. With their unique blend of low-power consumption, rich instruction set, and extensive memory options, these microcontrollers stand as the ideal choice for applications requiring compact yet robust performance. Whether you are an experienced developer or a newcomer to microcontrollers, this guide empowers you with the knowledge to fully harness the potential of the ATtiny25/45/85 series in your projects.

To unlock new levels of efficiency, creativity, and potential for your embedded projects, don’t hesitate to contact ICRFQ for more information and to place your order. Give your projects the edge they deserve with the ATtiny25/45/85 microcontrollers from ICRFQ now!

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