ATMEGA128-16MI - 8-Bit AVR MCU 128KB Flash 16MHz | Microchip
MPN： ATMEGA128-16MI ✓ 啟用中ATMEGA128-16MI 概覽
An 8-bit AVR microcontroller is a Harvard-architecture MCU in which program memory and data memory use separate buses, allowing most instructions to execute in a single clock cycle. Within the power-management hierarchy, the ATmega128 sits at the top of the classic ATmega family, acting as the system brain that orchestrates peripherals, sensors, and communication interfaces in embedded systems.
Key features include the AVR enhanced RISC core with 133 powerful instructions, 128 KB self-programmable Flash with a 2-wire (I2C/TWI) or SPI programming interface, two 8-bit and two 16-bit timers/counters, and rich connectivity: two UARTs, SPI, TWI (I2C), and an 8-channel 10-bit ADC. The 16 MHz speed grade (-16 suffix) supports industrial automation, metering, and motor-control workloads that smaller ATmega parts cannot handle.
Technically, the ATmega128 implements JTAG (IEEE 1149.1 compliant) for on-chip debugging and boundary scan, six sleep modes including power-down and power-save for battery designs, and an internal RC oscillator option alongside an external crystal input. Byte-writable EEPROM retains calibration data through power cycles, and the bootloader section permits field firmware updates over UART or SPI.
Typical applications include industrial control panels, HVAC and building automation, battery-powered data loggers, and legacy embedded products upgraded from smaller ATmega devices. The 64-QFN exposed-pad package suits space-constrained boards needing 53 general-purpose I/O lines.
A key design consideration: the MLF/QFN pad requires a solid ground pour with thermal vias; the -MI temperature range and QFN footprint must be confirmed against the TQFP (AU/AI) variants during layout migration.
This page synthesizes distributor pricing, drop-in alternatives, and practical design notes not found in the manufacturer datasheet.
直接替換替代品，適用於 ATMEGA128-16MI — 相同封裝，腳位對腳位相容。需重新設計 PCB 的不同封裝零件不列入。
此系列的變體
與下列產品可直接替換的同系列型號： ATMEGA128-16MI （相同外形與佔位） — 差異在於 ADC Channels, Package, Program Memory Size.
ATMEGA128A-16MI
✅ 直接替換 ⚠️ 規格未經驗證📋 參考替代品（不在目錄中）
ATMEGA1281-16MUR
✅ 直接替換 ⚠️ 規格未經驗證聯絡詢價
查看資料表 →ATMEGA128-16MI 最大額定值與電氣特性
| Core Processor | AVR 8-bit RISC |
| Core Size | 8-bit |
| Speed | 16 MHz |
| Program Memory Size | 128 KB (128K x 8) Flash |
| EEPROM Size | 4 KB |
| RAM Size | 4 KB SRAM |
| Number of I/O | 53 |
| Peripherals | SPI, UART, TWI (I2C), JTAG, PWM, WDT, Brown-out Detect/Reset |
| ADC Resolution | 10-bit |
| ADC Channels | 8 |
| Operating Voltage | 4.5 V to 5.5 V |
| Oscillator Type | Internal |
| 封裝 | 64-VFQFN Exposed Pad |
| 安裝類型 | Surface Mount |
| Data Converters | A/D 8x10-bit |
| Connectivity | SPI, UART/USART, TWI |
ATMEGA128-16MI 64-vfqfn exposed pad 腳位配置指南
ATMEGA128-16MI（64-vfqfn exposed pad 封裝）的腳位配置。 此數位 IC 包含 GPIO、通訊介面（UART、SPI、I2C）與電源腳位。替代腳位功能與配置選項請參閱製造商資料表。對嵌入式系統設計與 PCB 佈局至關重要。
無詳細腳位定義資料： ATMEGA128-16MI.
請參閱 資料表 以查看完整腳位配置。
典型應用
ATMEGA128-16MI 適用於 6 應用s: Industrial Control Panels, Building Automation and HVAC, Battery-Powered Data Loggers, Motor Control and PWM Actuation, Legacy Product Maintenance and AVR Upgrades, Metering and Sensor Hubs.
Industrial Control Panels
The ATMEGA128-16MI fits industrial panel controllers because its 53 GPIO lines, dual UARTs, SPI, and TWI (I2C) can simultaneously drive relays, an HMI, and field sensors. The 16 MHz AVR core delivers 16 MIPS single-cycle throughput, sufficient for deterministic scanning of digital inputs and PID loops, while the 128 KB self-programmable Flash leaves room for protocol stacks and OTA-style bootloader updates over UART. The 8-channel 10-bit ADC reads 0-10 V-scaled analog transducers, and the brown-out detector plus watchdog timer ensure safe restart after mains disturbances. The exposed-pad VFQFN provides a solid ground reference for noise immunity in electrically harsh cabinets.
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Building Automation and HVAC
In HVAC controllers, the ATMEGA128-16MI handles multi-zone sensing and actuation using its 8-channel 10-bit ADC for temperature and humidity inputs and TWI (I2C) for digital sensor buses. The 4 KB EEPROM stores zone setpoints and calibration tables across power cycles, while 4 KB SRAM buffers communication frames for Modbus-style UART links (two UARTs available). Six sleep modes, including power-save with an asynchronous timer, keep standby consumption low in thermostat-class products. The 128 KB Flash accommodates a full control algorithm, bootloader, and diagnostic logging without external memory, reducing BOM cost and board area in the 64-QFN footprint.
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Battery-Powered Data Loggers
The ATMEGA128-16MI serves data-logger designs that need substantial Flash for logged records and multiple communication channels. Its 128 KB Flash can hold both firmware and a reserve log partition written via self-programming, while the 4 KB EEPROM stores configuration wear-levelling structures. Power-save and power-down sleep modes reduce average current between sampling intervals, and the watchdog guarantees recovery from brownouts in the field. One UART streams data over RS-485 while the second services a local service port; SPI connects fast ADCs or SD-card media. Designers should prefer the 8 MHz voltage range variant when the rail is below 4.5 V, since the 16 MHz grade is 5 V-only.
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Motor Control and PWM Actuation
With four timers (two 8-bit, two 16-bit) providing multiple PWM channels, the ATMEGA128-16MI can drive brushed-DC and stepper motor stages with software or hardware PWM at 16 MHz resolution. The 10-bit ADC supports back-EMF and current sampling for closed-loop control, and the comparator input enables cycle-by-cycle protection schemes. The 53 GPIO lines allow direct interfacing with limit switches, encoders, and HMI buttons in one MCU, replacing multi-chip solutions. Designers typically pair the MCU with Infineon gate drivers or smart switches; the exposed-pad package grounds switching noise effectively, though layout care is needed to keep ADC references clean from PWM return currents.
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Legacy Product Maintenance and AVR Upgrades
Many installed-base products were designed around the ATmega128; the ATMEGA128-16MI keeps those boards in production. Because the ATmega128A variant is pin-to-pin and firmware-compatible, service organizations can qualify replacements quickly. The JTAG interface (IEEE 1149.1) supports boundary-scan test and on-chip debugging on existing fixtures, and the SPI-based ISP path allows field reflashing without desoldering. The 64-VFQFN package matches legacy MLF footprints directly. For designs migrating from the 40-pin ATmega8515 or ATmega103, the ATmega128 offers a documented register-level migration path with expanded Flash, EEPROM, and peripheral set in the MegaCore open-source Arduino support package.
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Metering and Sensor Hubs
Electricity, water, and gas meter front-ends benefit from the ATMEGA128-16MI's combination of a 10-bit ADC, hardware TWI and SPI buses, and large self-programmable Flash for tariff tables and event logs. The dual UARTs link a metrology front-end on one channel and an AMR/AMI communication modem on the other. EEPROM retains billing-relevant calibration constants through battery swaps, and the brown-out detector plus power-on reset guarantee state integrity during outages. The 16 MHz core executes CRC and AES-class software routines at acceptable speed, while the 64-QFN exposed-pad package supports compact, conformally coated meter PCBs with solid grounding for front-end accuracy.
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推薦產品摘要
工程參考資料，適用於 ATMEGA128-16MI — 比較、設計指引及合規資訊。
選型指南
與替代品比較
| 參數 | 本產品 | ATMEGA128A-16MI | ATMEGA1281-16MUR |
|---|---|---|---|
| Package | 64-VFQFN Exposed Pad | 64-VFQFN Exposed Pad - same | 64-VQFN (different die pinout) |
| Brand | Microchip Technology | Microchip Technology | Microchip Technology |
| Core / Speed | AVR 8-bit, 16 MHz | AVR 8-bit, 16 MHz | AVR 8-bit, 16 MHz |
| Flash | 128 KB | 128 KB | 128 KB |
| EEPROM | 4 KB | 4 KB | 4 KB |
| SRAM | 4 KB | 4 KB | 8 KB |
| I/O Count | 53 | 53 | 54 |
| Special Features | JTAG OCD + boundary scan | JTAG OCD + boundary scan | RTC, real-time counter; debugWIRE-style OCD (no JTAG) |
| Firmware Compatibility | Reference (ATmega128) | 100% compatible | Register map differs - porting required |
主要差異化特點
- JTAG on-chip debug and boundary scan (對比ATMEGA1281-16MUR)
- True drop-in second source within family (對比ATMEGA128A-16MI)
- Trade-off: 5 V-only operation (對比ATMEGA1281-16MUR)
設計說明
The 64-VFQFN exposed pad is the primary ground connection. Create a solder-paste window array under the exposed pad and connect it to the ground plane with an array of thermal vias (typically 4x4, 0.3 mm drills). Insufficient pad soldering is the most common cause of intermittent resets and ADC noise on MLF-packaged AVRs. Follow the land-pattern guidance in the Microchip ATmega128 datasheet and consider X2 inspection since the pad is hidden after reflow.
The -16 speed grade is specified only from 4.5 V to 5.5 V. Running the part at 3.3 V risks out-of-spec timing margins. Decouple VCC with 100 nF ceramics at each supply pair plus a 10 uF bulk capacitor, placed within a few millimeters of the pins. If your rail can droop below 4.5 V, enable the internal brown-out detector at an appropriate threshold (e.g., 4.0 V) so the MCU does not execute corrupted code during supply sags.
On the ATmega128, the JTAG-enable fuse is programmed by default; JTAG pins PC7-PC2 are not usable as GPIO unless the fuse is cleared. Also note the USART1 and ADC multiplexing conflicts on Port F, and that the ATmega103 compatibility mode fuse must be disabled to access the full register map and I/O set. These three fuse settings (JTAGEN, M103C, and clock sources) account for most bring-up failures when migrating designs from smaller ATmega devices.
合規資訊
Compliance status was not stated in the provided web data. Verify RoHS/REACH status on the official Microchip product page for ATMEGA128-16MI before procurement.
