ATMEGA168-20MUR - AVR 8-Bit MCU 20MHz 16KB Flash | Microchip
MPN: ATMEGA168-20MUR ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $3.76 | $3.76 |
| 10 | $3.42 | $34.20 |
| 100 | $3.05 | $305.00 |
| 500 | $2.75 | $1,375.00 |
| 1,000 | $2.12 | $2,120.00 |
ATMEGA168-20MUR Overview
A microcontroller (MCU) is a single-chip computer that integrates a processor core, program memory, data memory, and peripherals such as timers, ADCs, and serial interfaces. Within the power management hierarchy of embedded systems, the 8-bit MCU family (ATmega -> AVR -> 8-bit RISC microcontroller -> semiconductor IC) occupies the entry-to-mid tier of embedded control, ideal for cost- and power-sensitive applications that do not require 32-bit processing power.
Key features include 131 powerful instructions with most executed in a single clock cycle, delivering up to 20 MIPS throughput at 20MHz. The device combines 16KB self-programmable Flash with read-while-write support, 512B EEPROM, 1KB SRAM, 23 general-purpose I/O lines, and 32 general-purpose working registers. An 8-channel 10-bit ADC, three flexible timer/counters, USART, SPI, and I2C (TWI) serial interfaces round out the peripheral set, while debugWIRE enables on-chip debugging over a single pin.
The advanced RISC Harvard architecture separates instruction and data buses for parallel fetch and execution. In-System Programmable (ISP) Flash permits firmware updates on the assembled PCB, and the ICSP interface uses only two I/O pins plus reset.
Typical applications include industrial control and automation nodes, consumer appliances, and battery-powered portable instruments, where the 2.7V to 5.5V supply range and low-power modes extend battery life.
Design consideration: at 20MHz operation the supply voltage must be 3.8V or higher per the speed-versus-voltage curve, so 5V rails are recommended for maximum clock rates.
This page synthesizes distributor pricing, drop-in alternatives, pinout, and practical design notes not found in the manufacturer datasheet.
Drop-in alternatives for ATMEGA168-20MUR — same package, pin-to-pin compatible. Different-package parts requiring PCB rework are excluded.
Variants in this series
Same-series models that are drop-in compatible with ATMEGA168-20MUR (same form factor and footprint) — differing in Package, Timers, Operating Temperature, ADC Channels, Programming.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
ATMEGA168-20MU
✅ Drop-In✓ In Stock
Contact for price
View Datasheet →ATMEGA168P-20MUR
✅ Drop-In✓ In Stock
$1.58 / Unit
View Datasheet →ATMEGA168PA-MU
✅ Drop-In✓ In Stock
$1.72 / Unit
View Datasheet →ATMEGA328P-MU
✅ Drop-In ⚠️ 参数待验证📋 Reference alternative (not in catalog)
ATMEGA168A-MU
✅ Drop-In✓ In Stock
$1.38 / Unit
View Datasheet →ATMEGA328-MU
✅ Drop-In ⚠️ 参数待验证📋 Reference alternative (not in catalog)
ATMEGA168-20MUR Maximum Ratings & Electrical Characteristics
| Core Processor | AVR |
| Core Size | 8-Bit |
| Speed | 20 MHz |
| Program Memory Size | 16 KB (8K x 16) FLASH |
| EEPROM Size | 512 B |
| RAM Size | 1 KB |
| Supply Voltage Range | 2.7 V to 5.5 V |
| Number of I/O | 23 |
| ADC Resolution | 10-bit |
| ADC Channels | 8 (TQFP/QFN packages) |
| Timers | Three flexible timer/counters |
| Communication Interfaces | USART, SPI, I2C (TWI) |
| Operating Temperature | -40C to +85C (Industrial) |
| Package | 32-VQFN (5x5 mm) exposed pad |
| Mounting Type | Surface Mount |
| On-Chip Debug | debugWIRE |
| Programming | ISP, ICSP (2 I/O pins + reset) |
| Lifecycle Status | Active |
| RoHS Status | Compliant (Green) |
ATMEGA168-20MUR Pin Configuration
| Pin 1 | PD3 — Port D bit 3 (GPIO / INT1) |
| Pin 2 | PD4 — Port D bit 4 (GPIO / XCK/T0) |
| Pin 3 | GND — Ground |
| Pin 4 | VCC — Digital supply voltage |
| Pin 5 | GND — Ground |
| Pin 6 | VCC — Digital supply voltage |
| Pin 7 | PB6 — Port B bit 6 / XTAL1 (clock input) |
| Pin 8 | PB7 — Port B bit 7 / XTAL2 (clock output) |
| Pin 9 | PD5 — Port D bit 5 (GPIO / T1 / OC0B) |
| Pin 10 | PD6 — Port D bit 6 (GPIO / AIN0 / OC0A) |
| Pin 11 | PD7 — Port D bit 7 (GPIO / AIN1) |
| Pin 12 | PB0 — Port B bit 0 (GPIO / ICP1 / CLKO) |
| Pin 13 | PB1 — Port B bit 1 (GPIO / OC1A) |
| Pin 14 | PB2 — Port B bit 2 (GPIO / SS / OC1B) |
| Pin 15 | PB3 — Port B bit 3 (GPIO / MOSI / OC2A) |
| Pin 16 | PB4 — Port B bit 4 (GPIO / MISO) |
| Pin 17 | PB5 — Port B bit 5 (GPIO / SCK) |
| Pin 18 | AVCC — ADC supply voltage |
| Pin 19 | ADC6 — ADC input channel 6 |
| Pin 20 | AREF — Analog reference voltage |
| Pin 21 | GND — Ground |
| Pin 22 | ADC7 — ADC input channel 7 |
| Pin 23 | PC0 — Port C bit 0 (GPIO / ADC0 / SCL) |
| Pin 24 | PC1 — Port C bit 1 (GPIO / ADC1 / SDA) |
| Pin 25 | PC2 — Port C bit 2 (GPIO / ADC2) |
| Pin 26 | PC3 — Port C bit 3 (GPIO / ADC3) |
| Pin 27 | PC4 — Port C bit 4 (GPIO / ADC4 / SDA) |
| Pin 28 | PC5 — Port C bit 5 (GPIO / ADC5 / SCL) |
| Pin 29 | PC6 — Port C bit 6 / RESET (active-low reset) |
| Pin 30 | PD0 — Port D bit 0 (GPIO / RXD) |
| Pin 31 | PD1 — Port D bit 1 (GPIO / TXD) |
| Pin 32 | PD2 — Port D bit 2 (GPIO / INT0) |
Typical Applications
ATMEGA168-20MUR is suitable for 6 applications: Industrial Control and Automation, Battery-Powered Portable Instruments, Arduino-Compatible Hobby and Prototyping Boards, Consumer Appliance Control, Sensor Nodes and IoT Edge Devices, Motor and LED Lighting Control.
Industrial Control and Automation
The ATMEGA168-20MUR fits industrial control nodes because its -40C to +85C industrial temperature rating, 2.7V to 5.5V supply tolerance, and 20 MIPS throughput handle noisy factory-floor environments and deterministic loop control. In a typical PLC expansion module or sensor-transmitter board, the MCU runs a 10-bit ADC acquisition loop on up to 8 analog channels at 15 ksps, processes limit checks, and communicates over RS-485 via the USART with an external transceiver. The three flexible timer/counters generate PWM outputs for actuator drive with up to 16-bit resolution, while the 512B EEPROM stores calibration coefficients that survive power cycles. Flash self-programming allows field firmware updates over the existing bus without disassembly, reducing service cost.
Recommended
Battery-Powered Portable Instruments
For portable meters, data loggers, and handheld instruments, the ATMEGA168-20MUR combines a 2.7V supply floor with multiple sleep modes (idle, ADC noise reduction, power-save, power-down, standby) that cut average current draw to levels compatible with multi-year battery life. A typical handheld pH or temperature meter uses the 10-bit ADC with the internal 1.1V reference for ratiometric measurements, wakes from power-down on an external interrupt, samples, updates a segment LCD over SPI, and returns to sleep within milliseconds. At 20MHz the device completes the acquisition burst quickly, keeping the duty cycle short. Designers needing deeper battery life should consider the pin-compatible ATMEGA168PA-MU, whose picoPower technology reduces power-down current below 1 uA.
Recommended
Arduino-Compatible Hobby and Prototyping Boards
The ATMEGA168-20MUR is a natural fit for Arduino-compatible boards: the original Arduino platform family used ATmega168 devices, and the open-source MiniCore hardware package supports ATmega48/88/168/328 directly in the Arduino IDE. On a Uno-style board, the MCU reads shields through its 23 GPIO lines, services analog inputs via the 8-channel 10-bit ADC, and communicates over USB via an external USB-serial bridge connected to the USART. The ICSP header (two I/O pins plus reset) allows boot-loader flashing before the board ships, and debugWIRE provides single-wire in-circuit debugging on the same reset pin. The 20MHz grade outperforms the standard 16MHz Arduino clock, requiring only a boards.txt clock-frequency setting update.
Recommended
Consumer Appliance Control
Consumer appliances such as rice cookers, fan controllers, coffee machines, and small pump drives use the ATMEGA168-20MUR for its balance of cost, flash capacity, and integrated peripherals. The device reads front-panel keys through its ADC (multiple keys on one pin via resistor ladder), drives 7-segment or custom LCD displays over SPI/TWI, and generates triac or relay control signals using timer PWM with zero-cross synchronization from an external interrupt. The 16KB Flash accommodates a full control state machine plus a boot-loader for feature updates. Its 5V operation matches legacy transformer-based power supplies, and the 32-VQFN 5x5 mm footprint keeps two-layer control PCBs compact for tight enclosure constraints.
Recommended
Sensor Nodes and IoT Edge Devices
In wireless sensor nodes, the ATMEGA168-20MUR serves as the local processing and acquisition engine, pairing with sub-GHz or 2.4GHz radio modules over SPI. The 10-bit ADC digitizes up to 8 sensor channels (temperature, humidity, light, battery voltage), the TWI interface reads digital sensors, and the USART provides a debug/field-service console. The device sleeps in power-down mode between sampling intervals, waking on watchdog or external interrupts; memory usage is tuned to the 1KB SRAM with ring-buffered packet assembly. For designs where radio standby current dominates, the identical pinout allows swapping to the ATMEGA168PA-MU for sub-uA controller sleep without any layout change, preserving the validated PCB.
Recommended
Motor and LED Lighting Control
Small brushed-DC and stepper motor drives, as well as LED luminaires, use the ATMEGA168-20MUR for closed-loop speed and brightness regulation. Its three timer/counters produce up to four hardware PWM channels: two 8-bit timers handle fast PWM for LED dimming (kilohertz range to avoid flicker), while the 16-bit timer provides high-resolution phase-correct PWM for motor H-bridge control. The 10-bit ADC samples current-shunt and back-EMF feedback at up to 15 ksps, closing the control loop in firmware with PI regulation. The 5V I/O directly drives MOSFET gate drivers, and the industrial temperature range supports enclosed fixtures with elevated ambient temperatures where consumer-grade parts would fail.
Recommended
Recommended Products Summary
Engineering reference data for ATMEGA168-20MUR — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | ATMEGA168-20MU | ATMEGA168P-20MUR | ATMEGA168PA-MU | ATMEGA328P-MU |
|---|---|---|---|---|---|
| Package | 32-VQFN (5x5 mm) | 32-VQFN (5x5 mm) - same | 32-VQFN (5x5 mm) - same | 32-VQFN (5x5 mm) - same | 32-VQFN (5x5 mm) - same |
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Flash Memory | 16 KB | 16 KB | 16 KB | 16 KB | 32 KB |
| SRAM | 1 KB | 1 KB | 1 KB | 1 KB | 2 KB |
| EEPROM | 512 B | 512 B | 512 B | 512 B | 1 KB |
| Max Clock Speed | 20 MHz | 20 MHz | 20 MHz | 20 MHz | 20 MHz |
| Supply Voltage Range | 2.7 V to 5.5 V | 2.7 V to 5.5 V | 2.7 V to 5.5 V | 1.8 V to 5.5 V | 1.8 V to 5.5 V |
| Packaging | Tape & Reel | Tray | Tape & Reel | Tray | Tray |
Key Differentiators
- Full 20MHz grade at standard supply range (vs ATMEGA168PA-MU)
- Identical footprint allows no-PCB-change upgrades (vs ATMEGA328P-MU)
- Tape & Reel ready for high-volume SMT lines (vs ATMEGA168-20MU)
Design Notes
The 32-VQFN (MLF) package requires the exposed center pad to be soldered to a ground via array for both electrical grounding and thermal relief - skipping it causes erratic ADC results and reset glitches. Place 100 nF ceramic decoupling capacitors at BOTH VCC pins (pins 4 and 6) and one at AVCC (pin 18), each within 2 mm of the pad, plus a 10 uF bulk capacitor nearby. Connect AVCC to VCC through an LC filter (10 uH + 100 nF) when ADC accuracy matters, and keep the AREF trace short with its own 100 nF capacitor.
Operating at the full 20MHz grade requires a supply of approximately 3.8V or higher per the datasheet speed-versus-voltage curve; running 20MHz at 3.3V violates timing specifications and causes intermittent failures that are temperature-dependent and very hard to diagnose. For 3.3V systems, either derate the clock to 13.3MHz or below, or switch to the pin-compatible ATMEGA168PA-MU rated to 1.8V. Estimated: worst-case active current is roughly 12 mA at 5V/20MHz (datasheet order-of-magnitude figure), so size the 5V rail budget accordingly when multiple peripherals share the regulator.
debugWIRE multiplexes the on-chip debug interface onto the RESET pin (PC6, pin 29) - after enabling DWEN fuse, the external reset pull-up and capacitor load the single-wire bus and can prevent debug connection. Provide a series jumper on the reset line so debugWIRE and the external programmer (e.g., AVR ISP) do not fight each other. Also note that burning the RSTDISBL fuse converts PC6 to GPIO permanently and makes subsequent ISP programming impossible; Microchip application documentation warns this is effectively irreversible without high-voltage parallel programming.
PB6/PB7 (pins 7/8) default to the crystal function; when used as GPIO, clear the CKOUT and clock-select fuses appropriately or the port will not respond. When using the internal 8 MHz RC oscillator for cost savings, remember the -20MUR is specified at 20MHz with an external clock/crystal - the internal RC tolerance (roughly +/-10% across temperature per family datasheet) is unsuitable for USB bit-banging or precise UART at high baud rates. Always verify fuse settings in a programmer simulator before committing to production programming fixtures.
Compliance Information
Distributor data (FindIC) lists the part as GREEN / RoHS compliant. Formal REACH and conflict-minerals declarations should be obtained from Microchip compliance documentation.
