ATMEGA168-20MQ - 20MHz AVR 16KB Flash MCU | Microchip
MPN: ATMEGA168-20MQ β Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $3.81 | $3.81 |
| 10 | $3.43 | $34.30 |
| 100 | $3.05 | $305.00 |
| 500 | $2.74 | $1,370.00 |
| 1,000 | $2.47 | $2,470.00 |
ATMEGA168-20MQ Overview
An 8-bit AVR microcontroller is a Harvard-architecture RISC processor that combines program flash, data SRAM, and peripherals such as timers, UART, SPI, I2C (TWI), and ADC on a single chip. Within the power-management hierarchy of embedded systems, the ATmega168-class MCU occupies the entry-to-mid general-purpose controller tier, sitting above tinyAVR devices and below the 32-bit Cortex-M families. It is the classic engine of the Arduino ecosystem.
Key features include 131 mostly single-cycle instructions, 23 general-purpose I/O lines, 32 general-purpose working registers, an 8-channel 10-bit ADC, debugWIRE on-chip debug, and 1.8 V to 5.5 V family operation (20 MHz speed grade requires 4.5 V to 5.5 V). The Q variant suffix denotes extended temperature and green/RoHS packaging.
Technically, the advanced RISC core pipelines instruction fetch and execution so most instructions complete in one clock cycle, while read-while-write flash self-programming enables in-system firmware updates. Two 8-bit timers, one 16-bit timer, and a watchdog give flexible timing control, and the USART/SPI/TWI peripherals cover most serial connectivity needs.
Typical applications include industrial sensors and controls, consumer appliances, and Arduino-compatible embedded designs where the compact 5x5 mm MLF footprint conserves PCB area.
Design consideration: at 20 MHz the device must operate from 4.5 V to 5.5 V; decouple VCC/AVCC pins with 0.1 uF ceramics placed directly at the pads.
This page synthesizes distributor pricing, drop-in alternatives, and practical design notes not found in the manufacturer datasheet.
Drop-in alternatives for ATMEGA168-20MQ β 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 ATMEGA168-20MQ (same form factor and footprint) β differing in Package, Timers, Communication Interfaces, EEPROM Size, Program Memory Size.
Quick Comparison Tool β Select alternative parts for side-by-side comparison:
ATMEGA168-20MU
β Drop-In β οΈ εζ°εΎ ιͺθ―β In Stock
Contact for price
View Datasheet βATMEGA168-20MUR
β Drop-In β οΈ εζ°εΎ ιͺθ―β In Stock
$2.12 / Unit
View Datasheet βATMEGA168-15MD
β Drop-Inβ In Stock
$1.29 / Unit
View Datasheet βATMEGA168V-10MU
β Drop-In β οΈ εζ°εΎ ιͺθ―π Reference alternative (not in catalog)
ATMEGA328P-MU
β Drop-In β οΈ εζ°εΎ ιͺθ―π Reference alternative (not in catalog)
ATMEGA88-20MU
β Drop-In β οΈ εζ°εΎ ιͺθ―π Reference alternative (not in catalog)
ATMEGA168-20MQ Maximum Ratings & Electrical Characteristics
| Core Processor | AVR |
| Core Size | 8-Bit |
| Speed | 20 MHz |
| Throughput | Up to 20 MIPS at 20 MHz |
| Flash Memory | 16 KB (8K x 16) |
| EEPROM | 512 B |
| SRAM | 1 KB |
| General Purpose I/O | 23 |
| Working Registers | 32 |
| ADC | 8-channel 10-bit (on 32-pad packages) |
| Supply Voltage (family) | 1.8 V to 5.5 V |
| Supply Voltage (20 MHz speed grade) | 4.5 V to 5.5 V |
| Communication Interfaces | USART, SPI, I2C (TWI) |
| Timers | 2 x 8-bit, 1 x 16-bit |
| Debug | debugWIRE on-chip debug system |
| Package | 32-VQFN (5x5 mm) with exposed pad |
| Mounting Type | Surface Mount |
| RoHS Status | Compliant (green package) |
| Instructions | 131, most single-clock cycle |
ATMEGA168-20MQ Pin Configuration
| Pin 1 | PD3 β Port D, bit 3 (GPIO) |
| Pin 2 | PD4 β Port D, bit 4 (GPIO / XCK/T0) |
| Pin 3 | GND β Ground |
| Pin 4 | VCC β Digital supply voltage |
| Pin 5 | GND β Ground |
| Pin 6 | VCC β Digital supply voltage |
| Pin 7 | PB6 β Port B, bit 6 (GPIO / XTAL1 clock input) |
| Pin 8 | PB7 β Port B, bit 7 (GPIO / XTAL2 clock output) |
| Pin 9 | PD5 β Port D, bit 5 (GPIO / T1) |
| Pin 10 | PD6 β Port D, bit 6 (GPIO / AIN0) |
| Pin 11 | PD7 β Port D, bit 7 (GPIO / AIN1) |
| Pin 12 | PB0 β Port B, bit 0 (GPIO / ICP1/CLKO) |
| Pin 13 | PB1 β Port B, bit 1 (GPIO / OC1A) |
| Pin 14 | PB2 β Port B, bit 2 (GPIO / SS/OC1B) |
| Pin 15 | PB3 β Port B, bit 3 (GPIO / MOSI/OC2A) |
| Pin 16 | PB4 β Port B, bit 4 (GPIO / MISO) |
| Pin 17 | PB5 β Port B, bit 5 (GPIO / SCK) |
| Pin 18 | AVCC β ADC supply voltage |
| Pin 19 | ADC6 β ADC input channel 6 |
| Pin 20 | AREF β Analog reference voltage |
| Pin 21 | GND β Ground |
| Pin 22 | ADC7 β ADC input channel 7 |
| Pin 23 | PC0 β Port C, bit 0 (GPIO / ADC0) |
| Pin 24 | PC1 β Port C, bit 1 (GPIO / ADC1) |
| Pin 25 | PC2 β Port C, bit 2 (GPIO / ADC2) |
| Pin 26 | PC3 β Port C, bit 3 (GPIO / ADC3) |
| Pin 27 | PC4 β Port C, bit 4 (GPIO / ADC4/SDA) |
| Pin 28 | PC5 β Port C, bit 5 (GPIO / ADC5/SCL) |
| Pin 29 | PC6/RESET β Reset input or Port C, bit 6 (GPIO) |
| Pin 30 | PD0 β Port D, bit 0 (GPIO / USART RXD) |
| Pin 31 | PD1 β Port D, bit 1 (GPIO / USART TXD) |
| Pin 32 | PD2 β Port D, bit 2 (GPIO / INT0) |
Typical Applications
ATMEGA168-20MQ is suitable for 6 applications: Industrial Sensor Nodes, Arduino-Compatible Hobby and Makerspace Boards, Consumer Appliance Control, Battery-Powered Portable Instruments, Motor and Lighting Control, Networking and Communication Adapters.
Industrial Sensor Nodes
The ATMEGA168-20MQ fits industrial sensor nodes because its 8-channel 10-bit ADC digitizes multiple analog sensors directly, while the 1.8-5.5 V family supply range and green extended-temperature package tolerate harsh factory environments. In a typical node the MCU samples thermistors or pressure bridges through the ADC, filters locally using the 1 KB SRAM, and transmits readings via the USART or TWI bus to a gateway. Running at 20 MIPS, there is ample headroom for lightweight filtering and CRC-checked serial protocols. Operating at 5 V also gives the ADC a wide, noise-tolerant input range compared with 3.3 V controllers, improving measurement resolution in electrically noisy cabinets.
Recommended
Arduino-Compatible Hobby and Makerspace Boards
The ATMEGA168-20MQ is a natural fit for Arduino-compatible boards: the ATmega168 was one of the original Arduino core MCUs, and community toolchains such as MiniCore support it directly. Its 16 KB flash hosts a bootloader plus a modest sketch, and debugWIRE allows in-circuit debugging without extra hardware on hobbyist boards. The compact 5x5 mm QFN suits small shields and wearable-sized boards, while the 20 MHz/5 V speed grade matches classic Arduino Uno-class timing assumptions. Designers should break out PB3/PB4/PB5 plus RESET as an ISP header so end users can re-flash bootloaders on assembled boards.
Recommended
Consumer Appliance Control
Consumer appliance controllers - rice cookers, coffee machines, small HVAC units - benefit from the ATMEGA168-20MQ's combination of 23 GPIO lines, three timers, and low unit cost. Two 8-bit timers generate phase-correct PWM for heater and fan control while the 16-bit timer handles timekeeping and zero-cross detection for triac dimming. The 10-bit ADC reads NTC temperature sensors and user potentiometers, and the TWI interface drives OLED or segment display controllers. The green RoHS package meets consumer environmental compliance requirements, and the 20 MHz throughput comfortably runs state machines plus safety interlock code simultaneously.
Recommended
Battery-Powered Portable Instruments
Although the 20 MHz MQ speed grade is specified at 4.5-5.5 V, portable instrument designers still select the ATmega168 family for its power-management features: idle, ADC noise reduction, power-save, power-down, and standby sleep modes with wake on pin change, watchdog, or timer. Using ATMEGA168V-10MU variants (same footprint) enables true 1.8-5.5 V low-voltage battery operation, letting one PCB design span mains-powered (20 MHz, 5 V) and battery-powered (10 MHz, 1.8 V) product lines. The 10-bit ADC with a 1.1 V internal reference supports battery-voltage and thermistor monitoring, and the USART handles USB-bridge or RF-module communication in handheld meters.
Recommended
Motor and Lighting Control
Small motor drivers and LED lighting controllers use the ATMEGA168-20MQ's PWM resources extensively: the two 8-bit timers provide multiple phase-correct PWM channels for DC motor speed or multi-channel LED dimming, and the 16-bit timer offers input capture for fan tachometer feedback or encoder reading. At 20 MHz, PWM resolution and loop rates exceed what is needed for typical brushed-DC and fan applications, while hardware SPI can feed LED driver ICs. The 5 V logic domain interfaces directly with common gate-driver and constant-current driver ICs, and the extended-temperature Q package survives enclosed lighting fixtures where ambient temperatures run high.
Recommended
Networking and Communication Adapters
The ATMEGA168-20MQ serves in low-cost network adapters, serial-to-Ethernet bridges, and RS-485 field devices where its hardware USART, SPI, and TWI peripherals connect PHYs and transceivers. The 20 MIPS throughput sustains respectable serial line rates and interrupt-driven buffering within the 1 KB SRAM, and the 16 KB flash accommodates lightweight TCP or Modbus stacks. The extended-temperature green package suits outdoor network nodes and rooftop sensors. Designers commonly pair the MCU with external SPI Ethernet controllers or RS-485 transceivers, and read-while-write self-programming allows field firmware updates over the communication link without a programmer attached.
Recommended
Recommended Products Summary
Engineering reference data for ATMEGA168-20MQ β comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | ATMEGA168-20MU | ATMEGA168-15MD | ATMEGA168V-10MU | ATMEGA328P-MU | ATMEGA88-20MU |
|---|---|---|---|---|---|---|
| Package | 32-VQFN (5x5 mm) MLF | 32-VQFN (5x5 mm) - same | 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 | Microchip Technology |
| Max Clock Speed | 20 MHz | 20 MHz | 15 MHz | 10 MHz | 20 MHz | 20 MHz |
| Flash Memory | 16 KB | 16 KB | 16 KB | 16 KB | 32 KB | 8 KB |
| SRAM | 1 KB | 1 KB | 1 KB | 1 KB | 2 KB | 512 B |
| EEPROM | 512 B | 512 B | 512 B | 512 B | 1 KB | 512 B |
| Supply Voltage at Max Speed | 4.5 V to 5.5 V | 4.5 V to 5.5 V | 4.5 V to 5.5 V | 1.8 V to 5.5 V | 1.8 V to 5.5 V (PicoPower) | 4.5 V to 5.5 V |
| GPIO / ADC Channels | 23 GPIO / 8-ch 10-bit ADC | 23 GPIO / 8-ch 10-bit ADC | 23 GPIO / 8-ch 10-bit ADC | 23 GPIO / 8-ch 10-bit ADC | 23 GPIO / 8-ch 10-bit ADC | 23 GPIO / 8-ch 10-bit ADC |
| Temperature Grade | Extended (Q suffix) | Industrial (standard U suffix) | Extended (D suffix) | Industrial (standard U suffix) | Industrial (standard U suffix) | Industrial (standard U suffix) |
Key Differentiators
- Extended-temperature green package in 20 MHz grade (vs ATMEGA168-20MU)
- Double the program memory within the same 32-pad QFN footprint (vs ATMEGA88-20MU)
- Cost advantage over the flash-upgraded variant (vs ATMEGA328P-MU)
Design Notes
The 20 MHz speed grade of the ATMEGA168-20MQ is only guaranteed at 4.5 V to 5.5 V. Do not attempt to run this specific part at 20 MHz from a 3.3 V rail - the family datasheet's frequency-vs-voltage curve derates maximum clock speed with falling VCC, and out-of-spec operation risks flash write corruption. For 3.3 V designs requiring the same footprint, switch to ATMEGA168V-10MU or ATMEGA328P-MU, which support 1.8 V to 5.5 V operation.
The 32-pad MLF/QFN package requires a good exposed-pad connection for grounding. Provide an array of 3x3 or 4x4 via-in-pad connections under the exposed pad to the ground plane for both thermal relief and signal integrity. Place 0.1 uF ceramic decoupling capacitors directly adjacent to both VCC pins (pads 4 and 6), AVCC (pad 18), and AREF (pad 20). Connect AVCC to VCC through a low-pass LC filter when ADC accuracy matters; never leave AVCC floating even if the ADC is unused.
On the QFN package, ADC6 and ADC7 (pads 19 and 22) exist only on TQFP/QFN parts and are dedicated ADC inputs with no digital function. Keep their traces short and away from crystal or PWM routing. If using an external crystal on PB6/PB7 (pads 7-8), keep the crystal within 5 mm of the pads with guard ground. debugWIRE shares the RESET line (pad 29) - reserve a 100-ohm series resistor footprint on RESET so debugWIRE and HV programming can coexist without PCB cuts.
PC6/RESET is configured as RESET by default and as GPIO only after clearing a fuse - changing it removes in-circuit reset capability and complicates ISP recovery. Also note that with only 16 KB flash, a bootloader plus feature-rich sketch can fill memory quickly; if firmware growth is expected over product life, prototype with the pin-identical ATMEGA328P-MU instead. Verify the Q-suffix extended temperature rating against your enclosure thermal profile before final qualification.
Compliance Information
Distributor listings state 'RoHS Compliant' and 'GREEN' package for the MQ suffix. REACH, halogen-free, and conflict-minerals status not stated in provided data.
