ATMEGA128L-8MJ - 8-bit AVR MCU, 128KB Flash, 8MHz | Microchip
Référence : ATMEGA128L-8MJ ✓ Actif| Qté | Prix unitaire | Total |
|---|---|---|
| 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 Présentation
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.
Alternatives de remplacement direct pour ATMEGA128L-8MJ — même boîtier, compatible broche à broche. Les références à boîtier différent nécessitant une retouche du PCB sont exclues.
Variantes de cette série
Modèles de la même série directement compatibles avec ATMEGA128L-8MJ (même facteur de forme et même empreinte) — différant par Package, SRAM, RoHS Status, Throughput, Timers/Counters.
Outil de comparaison rapide — sélectionnez des références alternatives pour une comparaison côte à côte :
ATMEGA128L-8MU
✅ Remplacement direct✓ En stock
$12.39 / unité
Voir la fiche technique →ATMEGA128-16MJ
✅ Remplacement direct ⚠️ Spécifications non vérifiées✓ En stock
$4.48 / unité
Voir la fiche technique →ATMEGA128-16MUR
✅ Remplacement direct ⚠️ Spécifications non vérifiées✓ En stock
$8.4 / unité
Voir la fiche technique →ATMEGA1281V-8MU
✅ Remplacement direct ⚠️ Spécifications non vérifiées✓ En stock
$5.92 / unité
Voir la fiche technique →ATMEGA128L-8MJ Valeurs maximales et caractéristiques électriques
| Core Architecture | 8-bit AVR RISC |
| Flash Program Memory | 128 KB (In-System Programmable, Read-While-Write) |
| SRAM | 4 KB |
| EEPROM | 4 KB |
| Fréquence d'horloge maximale | 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) |
| Boîtier | 64-VFQFN with Exposed Pad (MLF) |
| Type de montage | Surface Mount |
| Throughput | Approx. 8 MIPS at 8 MHz (most instructions single-cycle) |
Guide de configuration des broches du ATMEGA128L-8MJ 64-vfqfn with exposed pad (mlf)
Configuration des broches du ATMEGA128L-8MJ (boîtier 64-vfqfn with exposed pad (mlf)). Ce circuit intégré numérique comprend des GPIO, des interfaces de communication (UART, SPI, I2C) et des broches d'alimentation. Consultez la fiche technique du fabricant pour les fonctions alternatives des broches et les options de configuration. Indispensable pour la conception de systèmes embarqués et la conception de circuits imprimés.
Aucune donnée de brochage détaillée disponible pour ATMEGA128L-8MJ.
Consultez la fiche technique pour la configuration complète des broches.
Applications typiques
ATMEGA128L-8MJ convient pour 6 applications: 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.
Recommandé
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.
Recommandé
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.
Recommandé
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.
Recommandé
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.
Recommandé
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.
Recommandé
Récapitulatif des produits recommandés
Données de référence d'ingénierie pour ATMEGA128L-8MJ — comparaison, recommandations de conception et informations de conformité.
Guide de sélection
Comparaison avec les alternatives
| Paramètre | Ce produit | 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 |
Principaux différenciateurs
- Full low-voltage range with no clock penalty (vs ATMEGA128-16MJ)
- Direct ATmega103 PCB replacement (vs ATMEGA1281V-8MU)
- Doubled SRAM headroom for new designs (vs ATMEGA128L-8MU)
Notes de conception
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.
Informations de conformité
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.
