ATMEGA128-16MNR - 8-Bit AVR MCU 128KB 16MHz QFN-64 | Microchip
MPN: ATMEGA128-16MNR ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $18.06 | $18.06 |
| 10 | $17.2 | $172.00 |
| 100 | $15.8 | $1,580.00 |
| 500 | $14.6 | $7,300.00 |
| 1,000 | $13.9 | $13,900.00 |
ATMEGA128-16MNR Overview
An 8-bit AVR microcontroller is a Harvard-architecture RISC processor that executes most instructions in a single clock cycle, placing this device in the broader hierarchy of microcontroller unit (MCU) -> embedded processor -> integrated circuit. The ATmega128 family has long served as a workhorse for 5V industrial embedded designs, bridging the gap between small ATmega328-class devices and larger ATmega1280/2560 parts.
Key features include 131 powerful instructions with mostly single-cycle execution, delivering up to 16 MIPS throughput at 16 MHz; two 8-bit and two 16-bit timers with PWM and input capture; dual programmable USARTs; an SPI interface; a two-wire (I2C-compatible) interface; and an 8-channel 10-bit ADC. A JTAG interface with on-chip debugging (OCD) and boundary-scan capability is built in, and an on-chip boot loader section supports self-programming Flash firmware updates.
Technically, the device combines the AVR advanced RISC architecture with 32 general-purpose working registers, fully static operation, and an XMEM interface that addresses up to 64 KB of external memory via ports PA/PC. The 64-QFN exposed-pad package improves thermal and ground performance over the TQFP option while saving board area.
Typical applications include industrial control and automation, motor control and power management nodes, building/HVAC controllers, and legacy 5V systems requiring drop-in AVR upgrades. The 16 MHz -16 grade at 4.5-5.5V suits environments needing robust noise margins.
Design consideration: for full-speed operation at 16 MHz, use the 4.5V to 5.5V supply range; below that voltage the maximum safe clock derates per the datasheet frequency-versus-voltage curve.
This page synthesizes distributor pricing, drop-in alternatives, pinout, and practical design notes not found in a single manufacturer datasheet.
Drop-in alternatives for ATMEGA128-16MNR — 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 ATMEGA128-16MNR (same form factor and footprint) — differing in Package, ADC Channels, Flash Memory, Supply Voltage Range, Timers/Counters.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
ATMEGA128-16MU
✅ Drop-In✓ In Stock
$6.4 / Unit
View Datasheet →ATMEGA128-16MN
✅ Drop-In✓ In Stock
$7.44 / Unit
View Datasheet →ATMEGA1281-16MUR
✅ Drop-In ⚠️ 参数待验证✓ In Stock
$8.78 / Unit
View Datasheet →AT90CAN128-15MT
✅ Drop-In📋 Reference alternative (not in catalog)
AT90USB1287-MU
✅ Drop-In📋 Reference alternative (not in catalog)
ATMEGA128-16MNR Maximum Ratings & Electrical Characteristics
| Core Processor | AVR 8-bit RISC |
| Core Size | 8-bit |
| Speed | 16 MHz |
| Flash Memory | 128 KB (64K x 16) |
| SRAM | 4 KB |
| EEPROM | 4 KB |
| Supply Voltage Range | 4.5 V to 5.5 V |
| ADC Channels | 8-channel, 10-bit |
| Communication Interfaces | 2 x USART, SPI, TWI (I2C-compatible) |
| Timers | 2 x 8-bit, 2 x 16-bit |
| JTAG / Debug | Yes (on-chip debug and boundary scan) |
| I/O Count | 53 |
| Package | 64-VFQFN Exposed Pad (9x9 mm) |
| Mounting Type | Surface Mount |
| Throughput | 16 MIPS at 16 MHz |
| External Memory Interface | Up to 64 KB (XMEM) |
ATMEGA128-16MNR Pin Configuration
| Pin 1 | PEN — Programming enable for parallel/high-voltage programming |
| Pin 2 | PE0 (PDI/RXD0) — Port E bit 0 / UART0 receive data input |
| Pin 3 | PE1 (PDO/TXD0) — Port E bit 1 / UART0 transmit data output |
| Pin 4 | PE2 (XCK0/AIN0) — Port E bit 2 / UART0 clock / analog comparator input 0 |
| Pin 5 | PE3 (AIN1/OC3A) — Port E bit 3 / analog comparator input 1 / Timer3 PWM output A |
| Pin 6 | PE4 (OC3B/INT4) — Port E bit 4 / Timer3 PWM output B / external interrupt 4 |
| Pin 7 | PE5 (OC3C/INT5) — Port E bit 5 / Timer3 PWM output C / external interrupt 5 |
| Pin 8 | PE6 (T3/INT6) — Port E bit 6 / Timer3 clock input / external interrupt 6 |
| Pin 9 | PE7 (ICP3/INT7/CLKO) — Port E bit 7 / Timer3 input capture / interrupt 7 / system clock output |
| Pin 10 | VCC — Digital supply voltage |
| Pin 11 | GND — Ground |
| Pin 12 | PG0 (WR) — Port G bit 0 / external memory write strobe |
| Pin 13 | PG1 (RD) — Port G bit 1 / external memory read strobe |
| Pin 14 | PC0 (A8) — Port C bit 0 / external memory address line 8 |
| Pin 15 | PC1 (A9) — Port C bit 1 / external memory address line 9 |
| Pin 16 | PC2 (A10) — Port C bit 2 / external memory address line 10 |
| Pin 17 | PC3 (A11) — Port C bit 3 / external memory address line 11 |
| Pin 18 | PC4 (A12) — Port C bit 4 / external memory address line 12 |
| Pin 19 | PC5 (A13) — Port C bit 5 / external memory address line 13 |
| Pin 20 | PC6 (A14) — Port C bit 6 / external memory address line 14 |
| Pin 21 | PC7 (A15) — Port C bit 7 / external memory address line 15 |
| Pin 22 | AREF — ADC reference voltage |
| Pin 23 | GND — Ground |
| Pin 24 | AVCC — ADC and Port F supply voltage |
| Pin 25 | PF0 (ADC0) — Port F bit 0 / ADC channel 0 |
| Pin 26 | PF1 (ADC1) — Port F bit 1 / ADC channel 1 |
| Pin 27 | PF2 (ADC2) — Port F bit 2 / ADC channel 2 |
| Pin 28 | PF3 (ADC3) — Port F bit 3 / ADC channel 3 |
| Pin 29 | PF4 (ADC4/TCK) — Port F bit 4 / ADC channel 4 / JTAG test clock |
| Pin 30 | PF5 (ADC5/TMS) — Port F bit 5 / ADC channel 5 / JTAG test mode select |
| Pin 31 | PF6 (ADC6/TDO) — Port F bit 6 / ADC channel 6 / JTAG test data output |
| Pin 32 | PF7 (ADC7/TDI) — Port F bit 7 / ADC channel 7 / JTAG test data input |
| Pin 33 | GND — Ground |
| Pin 34 | PA0 (AD0) — Port A bit 0 / external memory address/data line 0 |
| Pin 35 | PA1 (AD1) — Port A bit 1 / external memory address/data line 1 |
| Pin 36 | PA2 (AD2) — Port A bit 2 / external memory address/data line 2 |
| Pin 37 | PA3 (AD3) — Port A bit 3 / external memory address/data line 3 |
| Pin 38 | PA4 (AD4) — Port A bit 4 / external memory address/data line 4 |
| Pin 39 | PA5 (AD5) — Port A bit 5 / external memory address/data line 5 |
| Pin 40 | PA6 (AD6) — Port A bit 6 / external memory address/data line 6 |
| Pin 41 | PA7 (AD7) — Port A bit 7 / external memory address/data line 7 |
| Pin 42 | PB0 (SS) — Port B bit 0 / SPI slave select |
| Pin 43 | PB1 (SCK) — Port B bit 1 / SPI serial clock |
| Pin 44 | PB2 (MOSI) — Port B bit 2 / SPI master data output |
| Pin 45 | PB3 (MISO) — Port B bit 3 / SPI master data input |
| Pin 46 | PB4 (OC0) — Port B bit 4 / Timer0 PWM output |
| Pin 47 | PB5 (OC1A) — Port B bit 5 / Timer1 PWM output A |
| Pin 48 | PB6 (OC1B) — Port B bit 6 / Timer1 PWM output B |
| Pin 49 | PB7 (OC2/OC1C) — Port B bit 7 / Timer2 PWM output / Timer1 PWM output C |
| Pin 50 | RESET — Active-low reset input / open-drain output |
| Pin 51 | VCC — Digital supply voltage |
| Pin 52 | GND — Ground |
| Pin 53 | XTAL2 — Crystal oscillator output 2 |
| Pin 54 | XTAL1 — Crystal oscillator input 1 |
| Pin 55 | PD0 (SCL/INT0) — Port D bit 0 / TWI clock / external interrupt 0 |
| Pin 56 | PD1 (SDA/INT1) — Port D bit 1 / TWI data / external interrupt 1 |
| Pin 57 | PD2 (RXD1/INT2) — Port D bit 2 / UART1 receive / external interrupt 2 |
| Pin 58 | PD3 (TXD1/INT3) — Port D bit 3 / UART1 transmit / external interrupt 3 |
| Pin 59 | PD4 (ICP1) — Port D bit 4 / Timer1 input capture |
| Pin 60 | PD5 (XCK1) — Port D bit 5 / UART1 external clock |
| Pin 61 | PD6 (T1) — Port D bit 6 / Timer1 external clock input |
| Pin 62 | PD7 (T2) — Port D bit 7 / Timer2 external clock input |
| Pin 63 | PG2 (ALE) — Port G bit 2 / external memory address latch enable |
| Pin 64 | GND — Ground |
Typical Applications
ATMEGA128-16MNR is suitable for 6 applications: Industrial Control and Automation, Motor Control and Drives, Building Automation and HVAC Controllers, Data Acquisition and Test Instrumentation, Legacy 5V Embedded System Upgrades, Security and Access Control Panels.
Industrial Control and Automation
The ATMEGA128-16MNR is well suited to industrial control nodes such as PLC I/O modules, sensor hubs, and machine controllers. Its 53 GPIO lines, external memory interface supporting up to 64 KB of XMEM, and dual USARTs allow direct connection to legacy RS-232/RS-485 field buses, HMI panels, and relay banks without external glue logic. The 4.5V-5.5V supply range provides the noise margins demanded by factory-floor environments, and the fully static core tolerates slow clocking for power-sensitive standby modes. With 16 MIPS of throughput and 128 KB of Flash, deterministic control loops and protocol stacks coexist comfortably in one device. The QFN-64 exposed-pad package also delivers robust ground and thermal performance on vibration-prone industrial PCBs.
Recommended
Motor Control and Drives
For DC, stepper, and small BLDC motor control, the ATMEGA128-16MNR offers four hardware PWM outputs (OC0, OC1A, OC1B, OC2), two 16-bit timers with input capture for speed feedback, and an 8-channel 10-bit ADC able to sample current shunts and position sensors. External INT4-INT7 pins handle quadrature encoder or Hall-sensor inputs at the 16 MHz core rate, closing control loops at kHz rates with predictable latency. Operating at 5V, the ADC benefits from the AVCC-referenced ratiometric measurement of shunt voltages. The 128 KB Flash space hosts FOC or trapezoidal commutation code plus protocol interfaces simultaneously, and the JTAG interface enables real-time in-circuit debugging of the control firmware during development.
Recommended
Building Automation and HVAC Controllers
The ATMEGA128-16MNR fits building automation nodes - damper actuators, temperature/ humidity controllers, and lighting schedulers - where 5V logic, plenty of I/O, and multiple serial ports are required. The TWI (I2C) interface polls environmental sensors while the ADC reads analog NTC thermistors across its 8-channel multiplexer, and the two USARTs bridge Modbus RTU networks to local service ports. With 4 KB EEPROM, configuration data and setpoints survive power loss without external memory. Deep sleep modes reduce idle consumption in battery-backed zones, and the boot-loader section allows field firmware updates over the existing Modbus or RS-485 link, eliminating physical access during service and reducing lifetime maintenance cost.
Recommended
Data Acquisition and Test Instrumentation
The ATMEGA128-16MNR serves as the acquisition engine in low-cost data loggers, bench instruments, and sensor front ends. Its 10-bit ADC with AREF-referenced ratiometric conversion delivers roughly 4.9 mV LSB resolution at 5V, adequate for thermistor, strain-gauge, and potentiometer channels, while timer input capture timestamps external events with 62.5 ns resolution at 16 MHz. The external memory interface (XMEM) attaches up to 64 KB of SRAM for buffering sample streams beyond the internal 4 KB, and logged data streams out over SPI to SD-card modules or over USART to a host PC. The QFN-64 exposed pad keeps ground bounce low across 53 simultaneously switching I/O when driving front-panel displays and indicators.
Recommended
Legacy 5V Embedded System Upgrades
Many deployed industrial and commercial products were designed around 5V logic, and the ATMEGA128-16MNR is the standard Microchip choice for sustaining or upgrading those platforms. It replaces earlier ATmega103-class designs with pin-compatibility heritage, doubles available memory, and adds JTAG debugging, all while preserving the 4.5V-5.5V supply rail and existing board-level I/O structures. Because the ATmega128 line is supported by AVR-GCC, Microchip Studio, and the MegaCore Arduino package, legacy firmware ports quickly, and the ISP/boot-loader capability permits in-field reflashing through the existing product housing. Choosing the RoHS-green -16MNR version also brings older assemblies into lead-free compliance without changing the power architecture.
Recommended
Security and Access Control Panels
In access control panels, alarm hosts, and keypad controllers, the ATMEGA128-16MNR combines ample I/O with the serial channels and nonvolatile storage these systems demand. Door strikes, magnetic reed switches, and tamper loops connect to GPIO with internal pull-ups; keypads and RFID reader modules attach via UART, TWI, or Wiegand emulated on interrupt pins. The 4 KB EEPROM retains user credential tables and event logs through outages, while the boot-loader section enables credential-database and firmware updates over the RS-485 supervision network. The 10-bit ADC monitors battery backup voltage and enclosure temperature, and sleep modes between polling cycles keep standby power within backup-battery budgets.
Recommended
Recommended Products Summary
Engineering reference data for ATMEGA128-16MNR — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | ATMEGA128-16MU | ATMEGA128-16MN | ATMEGA1281-16MUR | AT90CAN128-15MT | AT90USB1287-MU |
|---|---|---|---|---|---|---|
| Package | 64-QFN (9x9 mm) | 64-QFN (9x9 mm) - same | 64-QFN (9x9 mm) - same | 64-QFN (9x9 mm) - same | 64-QFN (9x9 mm) - same | 64-QFN (9x9 mm) - same |
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Flash Memory | 128 KB | 128 KB | 128 KB | 128 KB | 128 KB | 128 KB |
| SRAM | 4 KB | 4 KB | 4 KB | 8 KB | 4 KB | 8 KB |
| Max Clock Speed | 16 MHz | 16 MHz | 16 MHz | 16 MHz | 16 MHz (15 MIPS rated) | 16 MHz |
| Special Communication Module | 2 x USART, SPI, TWI | 2 x USART, SPI, TWI | 2 x USART, SPI, TWI | 2 x USART, SPI, TWI | + CAN 2.0A/B controller | + Full-speed USB device controller |
| Firmware Port Effort from ATmega128 | N/A (baseline) | None (same die) | None (same die) | Minor (register map differences) | Minor (header/porting changes) | Minor (header/porting changes) |
Key Differentiators
- Deterministic single-cycle RISC core at 16 MIPS (vs AT90CAN128-15MT)
- RoHS green packaging without die change (vs ATMEGA128-16MN)
- Lower cost than USB/CAN derivatives for non-networked designs (vs AT90USB1287-MU)
- Trade-off: 4 KB SRAM only (vs ATMEGA1281-16MUR)
Design Notes
The -16 speed grade requires 4.5V to 5.5V for full 16 MHz operation. Estimated: at 16 MHz with typical active current of roughly 20-25 mA, a 5V rail dissipates only about 100-125 mW in the MCU itself, so no heatsinking is needed - but ensure the exposed ground pad is soldered to a ground plane for the datasheet-referenced electrical performance. Connect AVCC to VCC through a low-pass filter (10 uH inductor with 0.1 uF capacitor) when ADC accuracy matters, and tie AREF to a clean reference with a 100 nF decoupling capacitor.
For the QFN-64 MLF package, design the land pattern per the Microchip QFN application note and reserve a via array (at least 3x3) under the exposed pad to stitch the die paddle to the ground plane - this pad is the primary ground return for the die. Place 100 nF ceramic decoupling capacitors within 2-3 mm of every VCC pin (pins 10 and 51) and AVCC (pin 24). If you plan future conversion to AT90CAN128 or AT90USB1287 derivatives, keep the same 9x9 mm QFN footprint so the drop-in alternative requires no PCB change.
Two frequent ATmega128 migration pitfalls: (1) The PEN pin (pin 1 on QFN) must be pulled high during normal operation or the device may enter parallel programming mode at reset - tie it to VCC through a 10 kOhm resistor. (2) JTAG pins PF4-PF7 default to JTAG function at reset; if you need them as ADC4-ADC7 or GPIO, clear the JTAGEN fuse. Also note the 128 KB Flash exceeds the 16-bit program counter range, so use the EICRA/EIND-style far-call mechanism (RAMPZ register) when calling functions or reading data above 64 KB.
When using the XMEM external memory interface at full 16 MHz, ports PA and PC drive the full address/data bus with fast edges - add 22-33 Ohm series termination resistors on long bus traces to suppress ringing and reduce EMI. Keep the XTAL1/XTAL2 crystal traces under 10 mm and surround them with a ground guard ring; for the 16 MHz full-speed grade use a parallel crystal with appropriate 12-22 pF load capacitors per the crystal datasheet, not a ceramic resonator if timing accuracy of UART baud rates is required.
Compliance Information
The R suffix designates RoHS-compliant green packaging per distributor listings ('QFN/MLF, 105C, GREEN, 5V, T&R'). REACH, halogen-free, and conflict minerals status should be confirmed against official Microchip compliance documentation for the specific date code.
