ATMEGA168-15MD - 8-bit AVR MCU 16KB Flash 32-VQFN | Microchip
MPN: ATMEGA168-15MD β Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $2.15 | $2.15 |
| 10 | $1.93 | $19.30 |
| 100 | $1.68 | $168.00 |
| 500 | $1.48 | $740.00 |
| 1,000 | $1.29 | $1,290.00 |
ATMEGA168-15MD Overview
A microcontroller unit (MCU) is a single-chip computer that integrates a processor core, memory, and programmable peripherals on one die. The ATmega168 belongs to the AVR family of 8-bit microcontrollers, which sits within the broader hierarchy of embedded processors and power-efficient control ICs. AVR MCUs execute most instructions in a single clock cycle, achieving throughput approaching 1 MIPS per MHz.
Key features include the Advanced RISC architecture with 133 powerful instructions, 32 general-purpose working registers, 23 general-purpose I/O lines, in-system programmable (ISP) FLASH with read-while-write capability, and a two-wire serial interface (I2C-compatible), plus SPI and USART serial ports. Peripheral set includes an 8-channel 10-bit ADC, timers with PWM outputs, and a programmable watchdog timer.
Architecturally, the AVR core uses a Harvard structure with separate program and data buses, allowing single-cycle instruction fetch and execution. The 16 KB FLASH supports 10,000 write cycles and is programmable via SPI (ICSP) using tools such as the MPLAB SNAP. Power management features include idle, power-down, and power-save sleep modes with wake-up on external interrupts.
Typical applications include consumer appliance control, HVAC and motor-adjacent control boards, sensor interfaces, and industrial automation nodes where a cost-sensitive 8-bit controller with rich analog peripherals is required. The 32-VQFN 5x5 mm footprint suits compact two-layer designs.
A key design consideration is voltage-versus-frequency derating: at lower supply voltages, the maximum safe clock frequency drops, so verify the speed grade against your VCC rail. This page synthesizes distributor pricing, drop-in alternatives, pinout data, and practical design notes not consolidated in the manufacturer datasheet.
Drop-in alternatives for ATMEGA168-15MD β same package, pin-to-pin compatible. Different-package parts requiring PCB rework are excluded.
Quick Comparison Tool β Select alternative parts for side-by-side comparison:
ATMEGA168-15MT1
β Drop-Inβ In Stock
$3.95 / Unit
View Datasheet βATMEGA168A-MU
β Drop-In β οΈ εζ°εΎ ιͺθ―π Reference alternative (not in catalog)
ATMEGA168PA-MU
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)
ATMEGA88PA-MU
β Drop-In β οΈ εζ°εΎ ιͺθ―π Reference alternative (not in catalog)
ATMEGA168-15MD Maximum Ratings & Electrical Characteristics
| Core | AVR 8-bit RISC |
| Data Bus Width | 8 bit |
| Program Memory Size | 16 KB (8K x 16) FLASH |
| Program Memory Type | ISP FLASH (read-while-write) |
| SRAM Size | 1 KB |
| EEPROM Size | 512 B |
| Maximum Clock Frequency | 16 MHz |
| Supply Voltage Range | 2.7 V to 5.5 V |
| Number of I/O Lines | 23 |
| Instructions | 133 (most single-cycle) |
| Working Registers | 32 general purpose |
| ADC | 8-channel 10-bit |
| Communication Interfaces | USART, SPI, 2-wire serial (I2C-compatible) |
| Timers | Two 8-bit, one 16-bit with PWM |
| Package | 32-VQFN exposed pad, 5x5 mm |
| Mounting Type | Surface Mount |
| Programming Interface | ICSP via SPI (MPLAB SNAP compatible) |
| Life Cycle Stage | Active |
ATMEGA168-15MD Pin Configuration
| Pin 1 | PD3 β Port D bit 3 (GPIO / USART / interrupt) |
| Pin 2 | PD4 β Port D bit 4 (GPIO / timer) |
| 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 (XTAL1 / TOSC1 when crystal used) |
| Pin 8 | PB7 β Port B bit 7 (XTAL2 / TOSC2 when crystal used) |
| Pin 9 | PD5 β Port D bit 5 (GPIO / timer PWM) |
| Pin 10 | PD6 β Port D bit 6 (GPIO / timer PWM) |
| Pin 11 | PD7 β Port D bit 7 (GPIO / analog comparator) |
| Pin 12 | PB0 β Port B bit 0 (GPIO / timer I/O) |
| Pin 13 | PB1 β Port B bit 1 (GPIO / timer PWM) |
| Pin 14 | PB2 β Port B bit 2 (GPIO / SS / analog comparator) |
| Pin 15 | PB3 β Port B bit 3 (GPIO / MOSI / OC2A PWM) |
| Pin 16 | PB4 β Port B bit 4 (GPIO / MISO) |
| Pin 17 | PB5 β Port B bit 5 (GPIO / SCK - ICSP clock) |
| Pin 18 | AVCC β ADC supply voltage |
| Pin 19 | ADC6 β ADC input channel 6 (analog only) |
| Pin 20 | AREF β Analog reference voltage for ADC |
| Pin 21 | GND β Ground |
| Pin 22 | ADC7 β ADC input channel 7 (analog only) |
| 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 β RESET (active-low, shared with PC6) |
| 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
ATMEGA168-15MD is suitable for 6 applications: Consumer Appliance Control, Industrial Sensor Nodes, Hobbyist and Maker Electronics, Battery-Powered Portable Devices, Motor and Actuator Control, Legacy BOM Maintenance.
Consumer Appliance Control
The ATMEGA168-15MD fits appliance control boards such as coffee makers, rice cookers, and small HVAC controllers because it integrates the MCU, 10-bit ADC for NTC temperature sensing, and PWM-capable timers for triac or relay drive timing in one low-cost 32-VQFN package. Its 16 KB FLASH accommodates state machines, button debouncing, and display multiplexing without external memory, while the 2.7 V to 5.5 V supply range allows direct operation from a 5 V standby rail. Sleep modes cut average current in always-on standby circuits, and the watchdog timer recovers from firmware lockups in unattended products.
Recommended
Industrial Sensor Nodes
In industrial sensing nodes, the ATMEGA168-15MD's 8-channel 10-bit ADC digitizes up to eight analog sensor channels such as 4-20 mA-derived voltages or bridge sensors, while the 2-wire serial interface and SPI connect external EEPROM or displays. The 16 MHz core executes filtering and scaling math fast enough for 100 Hz-class sampling loops, and 23 I/O lines drive local status LEDs and limit-switch inputs. Operating from a 5 V industrial rail simplifies the power tree, and the VQFN 5x5 mm footprint keeps node PCBs compact for DIN-rail or conduit-mounted enclosures.
Recommended
Hobbyist and Maker Electronics
The ATmega168 family is the historical core of Arduino-class boards, giving the ATMEGA168-15MD a vast ecosystem of bootloaders, libraries, and ICSP tooling. Designers can program it in-system via SPI using an MPLAB SNAP or compatible ICSP cable, and the 16 KB FLASH holds the classic optiboot-class bootloader plus a meaningful application sketch. Peripherals including USART, SPI, I2C, PWM timers, and the 10-bit ADC cover the majority of maker projects such as robotics, LED matrices, and environmental monitors. The 5 V tolerant 2.7 V to 5.5 V supply range matches common breadboard and shield power rails directly.
Recommended
Battery-Powered Portable Devices
For portable and battery-fed products, the ATMEGA168-15MD offers idle, power-down, and power-save sleep modes that reduce average current in duty-cycled operation, waking on external interrupts or watchdog timeouts. Its 2.7 V floor allows two-cell alkaline or single lithium-cell regulation topologies, and the 10-bit ADC monitors battery voltage for low-battery indication. Designs with the strictest current budgets should instead populate the pin-compatible ATMEGA168PA-MU, whose picoPower die cuts active and sleep current substantially. The 32-VQFN 5x5 mm package supports compact handheld PCBs without sacrificing the full peripheral set.
Recommended
Motor and Actuator Control
The ATMEGA168-15MD drives small DC and stepper motors through its PWM-capable timers: two 8-bit and one 16-bit timer generate complementary PWM outputs for H-bridge or driver-input control, while fast input-capture features read encoder feedback. The 16 MHz single-cycle core executes PI control loops at kHz rates with headroom, and the 10-bit ADC samples current-shunt or potentiometer feedback for closed-loop operation. Pairing the MCU with an external H-bridge keeps gate-drive noise off the controller die, and 23 I/O lines handle limit switches, enable lines, and fault inputs in a single low-cost device.
Recommended
Legacy BOM Maintenance
Many long-lifecycle products still specify the Atmel-era ATMEGA168-15MD ordering code, and this page exists to keep those builds maintainable. Where franchised stock is thin, the same-die ATMEGA168-15MT1 and the newer ATMEGA168A/168PA revisions in the identical 32-VQFN 5x5 mm footprint allow procurement to swap suffixes without PCB or firmware changes, provided fuse settings match. For boards being respun anyway, migrating to the pin-compatible ATMEGA328P-MU doubles FLASH headroom and secures long-term availability. Keeping a qualified second source on file protects production against broker-only allocation of legacy suffixes.
Recommended
Recommended Products Summary
Engineering reference data for ATMEGA168-15MD β comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | ATMEGA168-15MT1 | ATMEGA168A-MU | ATMEGA168PA-MU | ATMEGA328P-MU | ATMEGA88PA-MU |
|---|---|---|---|---|---|---|
| Package | 32-VQFN (5x5 mm) exposed pad | 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 |
| 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 | 1 KB |
| EEPROM | 512 B | 512 B | 512 B | 512 B | 1 KB | 512 B |
| Max Clock Frequency | 16 MHz | 16 MHz | 20 MHz | 20 MHz | 20 MHz | 20 MHz |
| Supply Voltage | 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 | 1.8 V to 5.5 V | 1.8 V to 5.5 V |
| Power Optimization | Standard ATmega168 die | Standard ATmega168 die | Improved die revision | picoPower (lowest current) | picoPower | picoPower |
| New-Design Suitability | Legacy maintenance only | Legacy maintenance only | Good | Good | Recommended | Good (small code) |
Key Differentiators
- Legacy Atmel-era ordering code for exact BOM continuity (vs ATMEGA168PA-MU)
- Lowest risk substitution footprint on this list (vs ATMEGA328P-MU)
- Guaranteed 16 MHz speed grade matching original system timing (vs ATMEGA168A-MU)
Design Notes
The ATMEGA168-15MD operates from 2.7 V to 5.5 V, but the 16 MHz speed grade is guaranteed at the upper end of that range. If your board runs at 3.3 V, consult the speed-versus-voltage derating curve in the Microchip ATmega168 datasheet and consider lowering the system clock or switching to a newer 1.8 V-capable revision such as ATMEGA168PA-MU. Decouple both VCC pads and AVCC with 100 nF ceramics placed within 2 mm of each pad, and always connect AVCC to VCC through an RC filter when ADC accuracy matters.
The 32-VQFN exposed pad on the package underside is the primary ground return and must be soldered to a grounded land pattern with an array of thermal vias. Avoid relying on perimeter pins alone for grounding - the die paddle carries significant switching current. For ICSP programming, route PB3/MOSI, PB4/MISO, PB5/SCK, and PC6/RESET to a standard 2x3 header so an MPLAB SNAP or equivalent ICSP programmer can reach the device in-circuit without lifting pins.
PC6 is RESET by default; using it as general-purpose I/O disables external reset and high-voltage programming is then required to recover. PB6/PB7 default to the crystal oscillator function - if you use an external crystal, keep load capacitors per the crystal datasheet; if these pins are used as GPIO, set the CKOUT/fuse options accordingly. When substituting the pin-compatible ATMEGA328P-MU or ATMEGA168PA-MU, re-verify fuse bytes and extended fuse settings, as defaults differ slightly between die revisions.
Compliance Information
Compliance status for the legacy -15MD suffix was not stated in the retrieved distributor data; confirm RoHS/REACH status on the Microchip product page or certificate of conformity before ordering.
