ATMEGA128-16MN - 8-Bit AVR MCU 128KB 16MHz 64-QFN | Microchip
MPN: ATMEGA128-16MN β Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $12.4 | $12.40 |
| 10 | $11.15 | $111.50 |
| 100 | $9.92 | $992.00 |
| 500 | $8.68 | $4,340.00 |
| 1,000 | $7.44 | $7,440.00 |
ATMEGA128-16MN Overview
A microcontroller is a single-chip computer that integrates a processor core, program memory, data memory, and peripherals such as timers, communication interfaces, and analog-to-digital converters. Within the embedded hierarchy, the ATmega128 belongs to the 8-bit AVR ATmega family, positioned under the broader categories of microcontroller units (MCUs), embedded processors, and integrated circuits. It executes most of its 131 powerful instructions in a single clock cycle, providing fully static operation.
Key features include an 8-channel 10-bit ADC for direct analog sensor interfacing, a JTAG interface for on-chip debugging and boundary-scan, two hardware USARTs for serial communication, plus SPI and TWI (I2C) buses. The four flexible timers (two 8-bit, two 16-bit with PWM) support motor control, lighting, and waveform generation. In-system programmable FLASH allows firmware updates without removing the device from the board.
Architecturally, the AVR uses an advanced Harvard structure with separate program and data buses and 32 general-purpose working registers directly connected to the ALU, achieving one-cycle instruction execution. The optional external memory interface can expand addressing for larger applications.
Typical applications include industrial automation and control panels, building and HVAC controllers, embedded instrumentation, and motor control systems that require 5V noise immunity, generous 128 KB code space, and field-updatable firmware.
A key design consideration is power dissipation: at 5V/16 MHz the device draws more current than its 8 MHz low-voltage siblings, so active clock management (idle, power-down modes) should be used in battery-sensitive designs. The QFN pad geometry requires an exposed-land PCB footprint.
This page synthesizes distributor pricing, drop-in alternatives, cross-reference findings, and practical design notes not found in the manufacturer datasheet. Price data is as of 2026-09-15.
Drop-in alternatives for ATMEGA128-16MN 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 ATMEGA128-16MN (same form factor and footprint) β differing in Package, Timers, Communication Interfaces, Throughput, Instruction Set.
Quick Comparison Tool β Select alternative parts for side-by-side comparison:
ATMEGA128-16MU
β Drop-Inβ In Stock
$6.4 / Unit
View Datasheet βATMEGA128A-16MN
β Drop-In β οΈ εζ°εΎ ιͺθ―π Reference alternative (not in catalog)
ATMEGA1281-16MUR
β Drop-Inβ In Stock
$8.78 / Unit
View Datasheet βATMEGA128-16MN Maximum Ratings & Electrical Characteristics
| Core Processor | AVR |
| Core Size | 8-Bit |
| Speed | 16 MHz |
| Throughput | 16 MIPS (at 16 MHz) |
| Instruction Set | 131 powerful instructions, most single-cycle |
| Program Memory Type | FLASH |
| Program Memory Size | 128 KB (64K x 16) |
| RAM Size | 4 KB (4K x 8) |
| EEPROM Size | 4 KB |
| Voltage - Supply (Vcc/Vdd) | 4.5 V to 5.5 V |
| ADC | 8-channel 10-bit |
| JTAG Interface | Yes (on-chip debugging and boundary scan) |
| Communication Interfaces | 2x USART, SPI, TWI (I2C) |
| Timers | 2x 8-bit, 2x 16-bit with PWM |
| Supplier Device Package | 64-QFN (9x9) |
| Package / Case | 64-QFN / MLF (9x9 mm) |
| Mounting Type | Surface Mount |
| Series | AVR ATmega |
| Green / RoHS Grade | GREEN, 105C |
| Packaging | Tray |
| Product Status | Active |
ATMEGA128-16MN 64-qfn / mlf (9x9 mm) Pin Configuration Guide
Pin configuration for ATMEGA128-16MN (64-qfn / mlf (9x9 mm) package). This digital IC includes GPIO, communication interfaces (UART, SPI, I2C), and power pins. Refer to the manufacturer datasheet for alternate pin functions and configuration options. Essential for embedded system design and PCB layout.
No detailed pinout data available for ATMEGA128-16MN.
Refer to the datasheet for full pin configuration.
Typical Applications
ATMEGA128-16MN is suitable for 6 applications: Industrial Automation and Control, Embedded Instrumentation and Data Acquisition, Building and HVAC Controllers, Motor Control and Actuation, Communication Nodes and Gateways, Consumer and 5V Legacy Equipment Maintenance.
Industrial Automation and Control
The ATMEGA128-16MN fits industrial controllers because its 4.5V-5.5V supply delivers the noise immunity that electrically harsh factory environments demand, while 128 KB FLASH holds substantial ladder-logic interpreters or protocol stacks. Two USARTs, SPI, and TWI (I2C) connect drives, HMIs, and I/O expansion without extra bridge chips, and the 8-channel 10-bit ADC reads analog transducers directly. In use, it typically runs a real-time control loop at 16 MHz (16 MIPS) while PWM timers drive actuators; the external memory interface scales RAM for data logging. Because the part is in-system programmable, field firmware updates avoid production-line downtime.
Recommended
Embedded Instrumentation and Data Acquisition
For benchtop meters, environmental loggers, and test fixtures, the ATMEGA128-16MN's 8-channel 10-bit ADC digitizes multiple sensor inputs at up to ~15 kSPS (datasheet ADC clock scaling), and the 4 KB EEPROM preserves calibration tables across power cycles. The JTAG interface enables deep on-chip debugging during instrument firmware development, while two USARTs stream results to a host PC or printer. At 16 MHz the core sustains 16 MIPS, sufficient for filtering and scaling math in real time. Designers typically pair it with precision voltage references and use power-down mode between samples to cut consumption in portable instruments.
Recommended
Building and HVAC Controllers
Thermostats, damper controllers, and boiler management boards benefit from the ATMEGA128-16MN's combination of a 5V-tolerant industrial supply, TWI (I2C) bus for connecting temperature/humidity sensors, and multiple PWM outputs for fan and valve control. The 128 KB FLASH accommodates complete PID control stacks, scheduling logic, and Modbus-style serial protocols on either USART. The GREEN 105C-grade MLF package suits enclosed controller PCBs. In application, the part idles between scheduler ticks using its power-management modes, and in-system programmability allows installers to load site-specific firmware without handling the chip.
Recommended
Motor Control and Actuation
With two 8-bit and two 16-bit timers offering PWM generation and input capture, the ATMEGA128-16MN drives DC, stepper, and brushed-actuator power stages via gate-driver companions. The 16 MHz/5V core executes commutation and current-loop math at 16 MIPS, while the 10-bit ADC samples shunt-derived feedback on up to eight channels. Typical implementations use Timer1/Timer3 complementary PWM into gate drivers, with USART or SPI links to a supervisory controller. The external memory interface can buffer motion profiles, and JTAG debugging simplifies tuning of current-control firmware on the live motor.
Recommended
Communication Nodes and Gateways
The ATMEGA128-16MN suits serial protocol converters, RS-485 field nodes, and small gateways: dual hardware USARTs let one port serve the field bus while the other talks to local peripherals, with hardware flow control available on the 5V-tolerant lines. 128 KB FLASH stores multiple protocol stacks simultaneously, and 4 KB SRAM buffers packet traffic; the TWI bus attaches RTCs and EEPROMs for configuration storage. At 16 MHz the core sustains 16 MIPS, comfortably handling CRC computation and framing in software. Power-down mode keeps duty-cycled wireless or wired nodes within modest energy budgets.
Recommended
Consumer and 5V Legacy Equipment Maintenance
A large installed base of 5V AVR designs relies on the ATMEGA128-16MN for repair, refurbishment, and end-of-life maintenance of appliances, vending machines, and legacy controllers. Because the MN variant is the GREEN 105C-grade 64-QFN version, it substitutes into existing MLF footprints without PCB changes, and identical AVR instruction-set compatibility means original firmware images program and run unchanged. Maintenance engineers typically re-flash via SPI ISP headers already present on service boards. The 4.5V-5.5V supply range keeps it compatible with aging 5V power trees still used in these products.
Recommended
Recommended Products Summary
Engineering reference data for ATMEGA128-16MN β comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | ATMEGA128-16MU | ATMEGA128A-16MN | ATMEGA1281-16MUR |
|---|---|---|---|---|
| Package | 64-QFN/MLF (9x9) | 64-QFN/MLF (9x9) - same | 64-QFN/MLF (9x9) - same | 64-QFN/MLF (9x9) - same |
| Brand | Microchip Technology (Atmel) | Microchip Technology (Atmel) | Microchip Technology (Atmel) | Microchip Technology (Atmel) |
| Core / Clock | AVR 8-bit / 16 MHz | AVR 8-bit / 16 MHz | AVR 8-bit / 16 MHz | AVR 8-bit / 16 MHz |
| Flash Memory | 128 KB | 128 KB | 128 KB | 128 KB |
| SRAM | 4 KB | 4 KB | 4 KB | 8 KB |
| EEPROM | 4 KB | 4 KB | 4 KB | 4 KB |
| Supply Voltage | 4.5 V - 5.5 V | 4.5 V - 5.5 V | 4.5 V - 5.5 V | 4.5 V - 5.5 V (16 MHz grade) |
| External Memory Interface | Yes | Yes | Yes | No |
| JTAG Debug | Yes | Yes | Yes | Yes |
| Firmware Compatibility | Baseline ATmega128 | Identical - true drop-in | Identical instruction set - drop-in (check errata) | Peripheral set differs - port required |
Key Differentiators
- True drop-in legacy continuity (vs ATMEGA128A-16MN)
- External memory interface retained (vs ATMEGA1281-16MUR)
- GREEN 105C-grade MLF compliance (vs ATMEGA128-16MU)
Design Notes
The 64-QFN/MLF (9x9 mm) package has a 0.5 mm pitch lead frame and a large central exposed pad that must be soldered to a grounded copper land for both mechanical retention and heat spreading. Use an NSMD pad pattern with via-in-pad or perimeter thermal vias (about 4x4 array) under the center pad. Note that MLF packages leave limited visual inspection area under the body, so plan for X-ray or electrical test coverage. The MLF footprint differs from the TQFP-64 land pattern of the AN variant, so footprints are not interchangeable across suffixes.
Estimated: at 5V/16 MHz active mode the ATmega128 draws on the order of 20-25 mA (per the datasheet active-current figure), giving roughly 100-125 mW core dissipation - small, but all VCC/GND pairs (multiple pins on this package) must each be decoupled with 100 nF ceramics placed within a few millimeters of the pins. AVCC should be isolated from the digital rail with an LC filter (ferrite plus 100 nF) to preserve the 10-bit ADC's effective resolution; a noisy AVCC can cost 2-3 LSB of accuracy.
Do not treat the MN (GREEN MLF) and AN (TQFP) suffixes as footprints interchangeable: the QFN leads sit under the body. Second, the ATmega128 external memory interface multiplexes address bits on port A - if XMEM is enabled, PA0-PA7 are consumed and cannot serve as GPIO, a frequent bring-up surprise. Third, when substituting ATMEGA1281-16MUR, register maps and pin multiplexing differ despite the same 128 KB FLASH, so firmware must be ported and retested. Finally, verify the JTAGEN fuse state; JTAG shares pins PF4-PF7 with the ADC.
On a 5V/16 MHz design, keep the XTAL1/XTAL2 crystal traces short (under 10 mm) with guard ground, and place the crystal load capacitors close to the pins. USART and SPI lines leaving the board benefit from series 22-33 ohm resistors to tame fast AVR edge rates and reduce EMI on unshielded cable runs. Because the QFN exposes a ground pad, a solid ground plane on layer 2 is straightforward and should be used as the return reference for all high-speed digital nets.
Compliance Information
Verified web data identifies the MN suffix as GREEN, 105C grade (green/RoHS-oriented manufacturing), QFN/MLF package. REACH and conflict-minerals status not stated in provided data.
