ATMEGA168-20MU

ATmega168-20MU is an 8-bit AVR microcontroller from Atmel (now Microchip). It uses the AVR RISC core (one instruction per cycle) with 32 general-purpose registers. Key on-chip memory: 16 KB flash program memory, 1 KB SRAM, and 512 B EEPROM. It runs up to 20 MHz; at that speed, supply is typically 4.5–5.5 V (lower speeds allow 1.8–5.5 V). Peripherals include three timers (two 8‑bit, one 16‑bit), a 10-bit ADC with up to 6 channels, and serial interfaces: USART, SPI, and I2C (TWI). It provides multiple I/O pins, PWM outputs, an analog comparator, and various interrupt sources. Features like sleep modes, watchdog timer, and brown-out detection aid power management. It supports In-System Programming via SPI. The “-20MU” suffix indicates a 20 MHz clock option in the MU (package) variant. This device is widely used in hobbyist and embedded projects (and is a predecessor/relative to the ATmega328P in Arduino boards).

Here are the key features of ATMEGA168-20MU (8-bit AVR, 28-pin SOIC variant):
- Core: AVR 8-bit RISC CPU, 32 general-purpose registers, single-cycle execute for most instructions
- Memory: 16 KB flash program memory, 1 KB SRAM, 512 bytes EEPROM
- Clock/Voltage: Up to 20 MHz operation; operating voltage typically 4.5–5.5V at 20 MHz (1.8–5.5V overall, speed dependent)
- Peripherals: 3 timers (Timer0 8-bit, Timer1 16-bit, Timer2 8-bit) with PWM outputs
- Analog: 8-channel, 10-bit ADC + Analog Comparator
- Communication: USART, SPI, I2C (TWI)
- I/O: Up to about 23 general-purpose I/O pins (on 28-pin package)
- Interrupts: Multiple interrupt sources with multiple vectored interrupts
- Debug/Programming: In-system programming (ISP) via SPI; JTAG interface for on-chip debugging on suitable packages
- Power management: Sleep modes (Idle, ADC Noise Reduction, Power-down, Power-save) and brown-out detector
- Boot/loading: Supports in-system bootloaders
Package: 28-pin SOIC (MU) form factor.

- Pin count: 32 pins (MU package, 32-pin TQFP/MLF)
- Function: ATmega168 is an 8-bit AVR microcontroller (embedded controller) with 16 KB flash, 1 KB EEPROM, 1 KB SRAM, running up to 20 MHz; includes USART, SPI, I2C (TWI), ADC, timers, and other peripherals for embedded control.

- Manufacturer: Microchip Technology Inc. (Atmel was acquired by Microchip in 2016; ATmega devices originated from Atmel).
- What kind of company: A global semiconductor company that designs and manufactures microcontrollers, memory, analog and other embedded ICs for embedded systems.

ATmega168-20MU is a small 8‑bit AVR microcontroller suitable for cost‑effective embedded systems. Typical application areas include:
- Consumer electronics and home automation (remote controls, thermostats, small appliances, clocks)
- Industrial sensing and instrumentation (temperature/humidity sensors, data loggers, panel meters)
- Robotics and motor control (PWM drive, sensor reading, simple controllers)
- Prototyping and education (hobby projects, Arduino‑like experiments)
- IoT and portable devices (with external interfaces)
- General low‑ to mid‑complexity control tasks requiring ADC, PWM, serial (USART/SPI/I2C) and timers

The ATmega168-20MU comes in a 28-pin SOIC (Surface-Mount) package. The MU suffix denotes the 28‑pin SOIC package type.