ATMEGA128L-8MJ - 8-bit AVR MCU, 128KB Flash, 8MHz | Microchip
料号： ATMEGA128L-8MJ ✓ 量产中| 数量 | 单价 | 小计 |
|---|---|---|
| 1 | $15.01 | $15.01 |
| 10 | $14.12 | $141.20 |
| 100 | $12.95 | $1,295.00 |
| 500 | $11.8 | $5,900.00 |
| 1,000 | $10.95 | $10,950.00 |
ATMEGA128L-8MJ 概述
An 8-bit AVR microcontroller is a Harvard-architecture RISC processor that executes most instructions in a single clock cycle. Within the power-management hierarchy, the ATmega128 family sits in the general-purpose mid-range segment: microcontroller -> embedded processor -> system-on-chip building block. The AVR core uses 32 general-purpose working registers directly connected to the ALU, allowing one-cycle execution that delivers approximately 8 MIPS at the 8 MHz maximum clock of this L-grade (low-voltage) variant.
Key features include 133 powerful instructions, 53 general-purpose I/O lines, four flexible Timer/Counters with compare modes and PWM, a Real Time Counter, and in-system programmable Flash with Read-While-Write capability for field firmware updates.
Communication and analog capability are comprehensive for its class: two USARTs, a byte-oriented Two-wire Serial Interface (TWI/I2C-compatible), an SPI serial port, an 8-channel 10-bit ADC, and a JTAG interface for on-chip debugging and boundary-scan. This peripheral set lets a single ATMEGA128L-8MJ replace a MCU plus separate UART, ADC, and EEPROM devices in cost-sensitive boards.
Typical applications include industrial control panels, building automation nodes, battery-powered instrumentation benefiting from the low-voltage L variant, and legacy designs originally built around the pin-compatible ATmega103, which the ATmega128 can directly replace.
Design consideration: keep the ADC reference clean and decouple AVCC, and note that at 8 MHz the device is specified across the full 2.7V-5.5V range, while 16 MHz operation would require the 16 MHz grade and 4.5V-5.5V supply.
This page synthesizes distributor pricing, drop-in alternatives, and practical design notes not found in the manufacturer datasheet.
直接替换替代料： ATMEGA128L-8MJ ——相同封装，引脚兼容。需要 PCB 改动的不同封装料号已排除。
本系列中的变体
可与以下型号直接替换的同系列型号： ATMEGA128L-8MJ （相同外形与封装尺寸） ——差异在于 Package, SRAM, RoHS Status, Throughput, Timers/Counters.
快速对比工具——选择替代料号进行并排对比：
ATMEGA128L-8MU
✅ 直接替换✓ 有现货
$12.39 / 个
查看数据手册 →ATMEGA128-16MJ
✅ 直接替换 ⚠️ 规格未核验✓ 有现货
$4.48 / 个
查看数据手册 →ATMEGA128-16MUR
✅ 直接替换 ⚠️ 规格未核验✓ 有现货
$8.4 / 个
查看数据手册 →ATMEGA1281V-8MU
✅ 直接替换 ⚠️ 规格未核验✓ 有现货
$5.92 / 个
查看数据手册 →ATMEGA128L-8MJ 最大额定值与电气特性
| Core Architecture | 8-bit AVR RISC |
| Flash Program Memory | 128 KB (In-System Programmable, Read-While-Write) |
| SRAM | 4 KB |
| EEPROM | 4 KB |
| 最大时钟频率 | 8 MHz |
| Operating Voltage Range | 2.7 V to 5.5 V |
| General Purpose I/O Lines | 53 |
| Working Registers | 32 x 8-bit |
| Timers/Counters | 4 (with compare modes and PWM) |
| Real Time Counter | Yes (RTC) |
| USART | 2 |
| Two-wire Serial Interface (TWI) | Yes (byte-oriented) |
| ADC | 8-channel, 10-bit |
| JTAG | Yes (on-chip debug and boundary scan) |
| 封装 | 64-VFQFN with Exposed Pad (MLF) |
| 安装类型 | Surface Mount |
| Throughput | Approx. 8 MIPS at 8 MHz (most instructions single-cycle) |
ATMEGA128L-8MJ 64-vfqfn with exposed pad (mlf) 引脚配置指南
ATMEGA128L-8MJ（64-vfqfn with exposed pad (mlf) 封装）的引脚配置。 该数字 IC 包含 GPIO、通信接口（UART、SPI、I2C）和电源引脚。请参阅制造商数据手册以了解复用引脚功能和配置选项。对嵌入式系统设计和 PCB 布局至关重要。
暂无详细引脚数据： ATMEGA128L-8MJ.
请参阅 数据手册 以查看完整引脚配置。
典型应用
ATMEGA128L-8MJ 适用于 6 应用s: Industrial Control Panels, Battery-Powered Instrumentation, Legacy ATmega103 Design Migration, Building Automation Nodes, Embedded Data Loggers, Motor Control and PWM Actuation.
Industrial Control Panels
The ATMEGA128L-8MJ fits industrial control panels because 128KB of ISP Flash accommodates large state-machine and HMI firmware, 53 GPIO lines drive relays, indicators, and keypads without expansion ICs, and two USARTs link to Modbus RTU field buses plus a local service port. The 2.7V-5.5V supply tolerance rides out noisy 5V rails, while the 10-bit ADC with eight channels reads potentiometers, sensors, and current-shunt circuits directly. The four timers with PWM outputs handle heater dimming and motor speed control, and the RTC supports time-stamped event logging to the 4KB EEPROM. Its industrial operating grade and JTAG debug support make commissioning and field diagnostics straightforward in panel environments.
推荐
Battery-Powered Instrumentation
The 'L' low-voltage grade makes the ATMEGA128L-8MJ a strong fit for battery-powered instruments: it is specified from 2.7V to 5.5V, so a two-cell lithium or single-cell with boost converter supplies the part with margin through the discharge curve, and the full 8 MHz clock remains available at 3.3V. The AVR sleep modes combined with the asynchronous RTC allow microamp-class standby between measurement cycles, while the 4KB EEPROM retains calibration constants without battery backup. The integrated 8-channel 10-bit ADC samples sensor bridges directly, avoiding a separate converter. 53 GPIO and TWI allow display and external FRAM expansion, letting one MCU span measurement, logging, and user-interface functions.
推荐
Legacy ATmega103 Design Migration
According to the Microchip datasheet, the ATmega128 is 100% pin compatible with ATmega103 and can replace it on existing printed circuit boards, with application note 'Replacing ATmega103 by ATmega128' detailing migration considerations. The ATMEGA128L-8MJ therefore serves maintenance engineers keeping ATmega103-era boards alive: the 64-QFN footprint drops onto the existing land pattern, the 128KB Flash doubles the code space of ATmega103, and the enhanced TWI and JTAG debug arrive for free. MIG2-compatible fuse settings and the M103 fuse mode ease transition of legacy firmware. For obsolete-controller obsolescence events, this is the lowest-risk, zero-PCB-rework migration path documented by the manufacturer.
推荐
Building Automation Nodes
In building automation, the ATMEGA128L-8MJ integrates sensing, actuation, and network communication in one device. Its byte-oriented TWI connects environmental sensors and RTC modules on a two-wire bus, two USARTs backhaul to RS-485 network converters, and SPI interfaces flash logging memory. The 10-bit ADC with eight channels samples temperature, humidity, and occupancy inputs, while four PWM timers drive damper motors and dimmable LED lighting channels. The 2.7V-5.5V operating range allows a shared 3.3V rail with modern sensors. With 128KB Flash, full BACnet-lite or proprietary protocol stacks fit comfortably, and the JTAG interface supports production boundary-scan testing of assembled nodes.
推荐
Embedded Data Loggers
The ATMEGA128L-8MJ suits embedded data-logger designs that must run unattended for months. The RTC provides accurate timestamping, the 4KB EEPROM survives power loss for rolling configuration and index storage, and SPI-connected SD or serial-flash media receives logged records through the hardware SPI port at low CPU overhead. Two USARTs allow one channel for GPS or modem modules and a second for local diagnostics. Sleep-mode current plus the low-voltage 2.7V-5.5V grade support primary-cell power budgets, and the ADC's internal reference options simplify sensor front ends. 128KB Flash holds protocol, compression, and file-system firmware with ample headroom for field firmware updates via Read-While-Write bootloading.
推荐
Motor Control and PWM Actuation
With four Timer/Counters offering compare modes and PWM, the ATMEGA128L-8MJ generates multiple independent PWM channels for DC motor, stepper, and actuator control. The 8 MHz core executes PID control loops in microseconds per iteration, leaving CPU margin for command parsing over USART. Ten-bit ADC inputs read back current shunts and position potentiometers, enabling closed-loop control without external converters. Operating to 5.5V simplifies gate-drive level compatibility with 5V logic MOSFET drivers, while the 64-QFN exposed pad provides a low-inductance ground for switching-noise immunity. Designers should keep analog traces away from PWM outputs and use the ADC noise-reduction sleep mode for sensitive sampling.
推荐
推荐产品汇总
工程参考数据： ATMEGA128L-8MJ ——对比、设计指导和合规信息。
选型指南
与替代料对比
| 参数 | 本产品 | ATMEGA128L-8MU | ATMEGA128-16MJ | ATMEGA128-16MU | ATMEGA1281V-8MU |
|---|---|---|---|---|---|
| Package | 64-VFQFN (Exposed Pad) | 64-VFQFN (Exposed Pad) - same | 64-VFQFN (Exposed Pad) - same | 64-VFQFN (Exposed Pad) - same | 64-MLF/QFN - same footprint |
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Flash | 128 KB | 128 KB | 128 KB | 128 KB | 128 KB |
| SRAM | 4 KB | 4 KB | 4 KB | 4 KB | 8 KB |
| Max Clock | 8 MHz | 8 MHz | 16 MHz | 16 MHz | 8 MHz |
| Supply Voltage | 2.7 V - 5.5 V | 2.7 V - 5.5 V | 4.5 V - 5.5 V | 4.5 V - 5.5 V | 2.7 V - 5.5 V |
| EEPROM | 4 KB | 4 KB | 4 KB | 4 KB | 4 KB |
关键差异点
- Full low-voltage range with no clock penalty （对比 ATMEGA128-16MJ)
- Direct ATmega103 PCB replacement （对比 ATMEGA1281V-8MU)
- Doubled SRAM headroom for new designs （对比 ATMEGA128L-8MU)
设计说明
Decouple every VCC/AVCC pin pair of the 64-QFN with 100 nF ceramic capacitors placed within 2 mm of the pins, plus one 10 uF bulk capacitor near the package. Connect the exposed pad to a solid ground plane with an array of vias - it is the primary thermal and ground return path. At 8 MHz and 5V, active current is in the tens of milliamps per the ATmega128 datasheet, so trace sizing is easy, but brown-out detection should be enabled via fuse for battery and industrial supplies.
Route the JTAG (TCK/TMS/TDO/TDI) header on all new boards even if unused - it provides production boundary-scan test and on-chip debug with MPLAB SNAP-class tools, and disabling JTAG later is a fuse setting. Keep the ADC front end (AREF, AVCC, sensing traces) physically separated from PWM and USART switching traces; use the ADC noise canceller sleep mode during sampling for best effective-bit performance.
Two frequent migration errors: first, the ATmega128 needs the M103 compatibility fuse explicitly disabled to access its full feature set (TWI, enhanced USART, extra SRAM mapping) when replacing an ATmega103 - leaving it set masks peripherals. Second, the L (8 MHz) and 16 MHz grades differ in supply range: an 8MJ run at 16 MHz or below 2.7V violates the datasheet operating envelope. Verify fuse bits and speed/voltage pairing before release.
合规信息
Compliance status for the ATMEGA128L-8MJ ordering code is not stated in the retrieved distributor data; request certificate of conformance from Microchip or your supplier.
