ATMEGA128L-8MUR - 8-bit AVR MCU 128KB 8MHz 64-QFN | Microchip
MPN: ATMEGA128L-8MUR ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $15.72 | $15.72 |
| 10 | $14.6 | $146.00 |
| 25 | $13.85 | $346.25 |
| 100 | $12.9 | $1,290.00 |
| 1,000 | $11.75 | $11,750.00 |
ATMEGA128L-8MUR Overview
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 of embedded systems, the MCU sits at the application layer, coordinating sensors, actuators, and communication interfaces while managing its own sleep and power modes. The AVR family pioneered single-cycle RISC execution in 8-bit MCUs, and the ATmega128 remains one of its most widely adopted flagship devices.
Key features include 133 powerful instructions (most single-cycle), 53 general-purpose I/O lines, an 8-channel 10-bit ADC, two 8-bit and two 16-bit timers with PWM, two USARTs, SPI, TWI (I2C), an analog comparator, and a JTAG interface for on-chip debugging and boundary scan. The wide 2.7V to 5.5V supply range of the L (low-voltage) grade allows direct operation from 3.3V or 5V rails.
Technically, the ATmega128 achieves up to 8 MIPS throughput at 8MHz, with six sleep modes (idle, ADC noise reduction, power-save, power-down, standby, extended standby) down to sub-uA power-down current levels. Self-programmable flash enables boot-loader based field updates, while the JTAG port supports IEEE-style on-chip debug via AVR JTAGICE tools.
Typical applications include industrial automation and process control nodes, building automation and metering, and low-power battery-operated instruments requiring both ample flash for protocol stacks and rich peripheral integration.
Design consideration: the MLF/QFN center pad must be soldered to a grounded PCB pad for reliable ground return; also note the MUR reel coding requires reflow assembly, not hand soldering.
This page synthesizes verified distributor pricing, drop-in alternatives, pin-compatibility guidance, and practical design notes not found in the manufacturer datasheet alone.
Drop-in alternatives for ATMEGA128L-8MUR — 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 ATMEGA128L-8MUR (same form factor and footprint) — differing in Package, SRAM, Supply Voltage Range, ADC Channels, Communication Interfaces.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
ATMEGA128L-8MU
✅ Drop-In✓ In Stock
$12.39 / Unit
View Datasheet →ATMEGA128-16MUR
✅ Drop-In✓ In Stock
$8.4 / Unit
View Datasheet →ATMEGA1281V-8MUR
✅ Drop-In✓ In Stock
$4.02 / Unit
View Datasheet →ATMEGA1281-16MUR
✅ Drop-In ⚠️ 参数待验证✓ In Stock
$8.78 / Unit
View Datasheet →ATMEGA128L-8MUR Maximum Ratings & Electrical Characteristics
| Core Processor | AVR 8-bit RISC |
| Core Size | 8-Bit |
| Speed (Max Clock) | 8 MHz |
| Flash Memory | 128KB (64K x 16) In-System Programmable |
| SRAM | 4KB |
| EEPROM | 4KB |
| Supply Voltage Range | 2.7 V to 5.5 V |
| Number of I/O | 53 |
| ADC Resolution | 10-bit, 8 channels |
| Timers | Two 8-bit, Two 16-bit |
| Communication Interfaces | 2x USART, SPI, TWI (I2C) |
| Debug Interface | JTAG (on-chip debug, boundary scan) |
| Package | 64-VFQFN Exposed Pad (MLF), 9x9 mm |
| Mounting Type | Surface Mount |
| Programmability | In-System Programmable (ISP), boot loader self-programming |
| Lifecycle Stage | ACTIVE |
ATMEGA128L-8MUR 64-vfqfn exposed pad (mlf), 9x9 mm Pin Configuration Guide
Pin configuration for ATMEGA128L-8MUR (64-vfqfn exposed pad (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 ATMEGA128L-8MUR.
Refer to the datasheet for full pin configuration.
Typical Applications
ATMEGA128L-8MUR is suitable for 6 applications: Industrial Automation & Process Control, Building Automation & Smart Metering, Battery-Powered Portable Instruments, Embedded Networking & Gateways, Motor Control & Embedded Actuation, Legacy Design Maintenance & ATmega103 Replacement.
Industrial Automation & Process Control
The ATMEGA128L-8MUR fits industrial control nodes because it combines 128KB of flash - enough for MODBUS or CAN-style protocol stacks plus application logic - with two USARTs that allow simultaneous RS-485 field-bus and HMI UART channels. Its 53 I/O lines drive relays, opto-isolated inputs, and stepper interfaces directly, while the 8-channel 10-bit ADC samples 0-10V-conditioned sensor inputs at up to 15 kSPS for closed-loop control. Operating from a 5V industrial rail (or 3.3V logic domains via the 2.7V floor), the device withstands noisy environments using its watchdog timer and brown-out detection. The JTAG port enables boundary-scan testing of assembled boards, reducing ICT fixture cost in production. Typical topology: ATmega128 polling sensors and a RS-485 transceiver, with SPI-connected data flash for logging.
Recommended
Building Automation & Smart Metering
Smart meters and building controllers benefit from the ATMEGA128L-8MUR's balance of non-volatile memory and low-power operation. The 4KB EEPROM stores tariff tables, calibration constants, and cumulative counters that must survive power loss for decades (rated 100,000 write cycles), while 128KB flash holds multi-protocol communication firmware. The device's sleep modes allow continuous battery-backed real-time operation: running a 32.768kHz watch crystal in asynchronous timer mode, the MCU wakes periodically to pulse-count energy inputs and returns to power-save mode. The TWI (I2C) bus interfaces RTC and display drivers; one USART drives an optical IR probe per IEC metering practice, the other a M-Bus or RS-485 uplink. Wide 2.7-5.5V operation tolerates battery sag without a regulator change.
Recommended
Battery-Powered Portable Instruments
Portable measurement instruments use the ATMEGA128L-8MUR because the L-grade core runs from a 3V lithium coin cell (2.7V floor leaves margin near end-of-life) and its power-down mode slashes average current to microamp levels between measurements. The 8-channel 10-bit ADC reads bridge sensors, thermistors, and potentiometer user interfaces; a 16-bit timer generates precise gate windows for frequency/flow counting. With 53 I/O, a single MCU drives a segment LCD via a character driver, keypad matrix, and buzzer without expansion ICs. 128KB flash accommodates calibration curves, multi-language UI strings, and an ISP boot loader for field firmware updates over the instrument's service connector - no disassembly needed. Designers typically clock at 1-4MHz from internal RC to minimize active current during measurement bursts.
Recommended
Embedded Networking & Gateways
The ATMEGA128L-8MUR serves as a protocol-conversion gateway because its dual USARTs, hardware SPI, and TWI permit three simultaneous communication domains under one MCU: for example, a sensor-side SPI radio module, a device-side TWI bus of peripherals, and an RS-232/485 service uplink. 128KB flash hosts concurrent protocol stacks (e.g., MODBUS RTU plus a proprietary sensor frame) with headroom for OTA boot loaders, and 4KB SRAM buffers packet frames without external RAM in typical message sizes. The 8MHz AVR core delivers roughly 8 MIPS, sufficient for CRC-checked framing at 115.2 kbaud on both UARTs. JTAG on-chip debugging lets firmware teams trace interrupt-level timing issues that plague UART-heavy designs. Wide-voltage operation bridges 3.3V radio modules and 5V field wiring with level-tolerant I/O.
Recommended
Motor Control & Embedded Actuation
The ATMEGA128L-8MUR drives small motor and actuator systems using its two 8-bit and two 16-bit timers, which generate up to six PWM channels for DC motor H-bridges, servo positioning, or BLDC trapezoidal schemes with Hall input capture. The 16-bit timer input-capture unit timestamps encoder edges with sub-microsecond resolution at 8MHz, while the analog comparator provides hardware over-current or stall trip. 53 I/O lines handle limit switches, brake relays, and status LEDs directly. With 128KB flash, motion profile generators (trapezoidal, S-curve) plus a command interpreter fit entirely on-chip. Two USARTs support daisy-chained multi-axis networks. Designers should pair the MCU with gate drivers on its PWM outputs and use the power-down watchdog for failsafe stops - the brown-out detector prevents corrupted PWM states during supply dips.
Recommended
Legacy Design Maintenance & ATmega103 Replacement
A primary ongoing use of the ATMEGA128L-8MUR is sustaining legacy products originally built around the ATmega103 or earlier ATmega128 variants. Per the Microchip ATmega128 datasheet (2467S), the ATmega128 is 100% pin compatible with ATmega103 and can replace it on existing printed circuit boards, with an application note ('Replacing ATmega103 by ATmega128') detailing fuse, register, and memory-map differences. For boards designed with the older 8MHz L-grade or 16MHz standard grade, the MUR reel part refreshes production lines with an active-lifecycle, in-system-programmable device while preserving the JTAG connector and ISP header already present. Reusing the same 64-QFN MLF footprint avoids PCB respin, qualification churn, and re-certification, making this part the standard last-buy bridge for aging AVR platforms.
Recommended
Recommended Products Summary
Engineering reference data for ATMEGA128L-8MUR — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | ATMEGA128L-8MU | ATMEGA128-16MUR | ATMEGA1281V-8MUR | ATMEGA128L-8AJ |
|---|---|---|---|---|---|
| Package | 64-QFN (MLF) 9x9 mm with exposed pad | 64-QFN (MLF) 9x9 mm - same | 64-QFN (MLF) 9x9 mm - same | 64-QFN (MLF) 9x9 mm - same | TQFP-64 (different footprint) |
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Max Clock Speed | 8 MHz | 8 MHz | 16 MHz | 8 MHz | 8 MHz |
| Flash Memory | 128KB | 128KB | 128KB | 128KB | 128KB |
| Supply Voltage Range | 2.7 V to 5.5 V | 2.7 V to 5.5 V | 4.5 V to 5.5 V | 1.8 V to 5.5 V (V-grade) | 2.7 V to 5.5 V |
| General-Purpose I/O | 53 | 53 | 53 | Reduced I/O count vs ATmega128 | 53 |
| Packaging Format | Tape & Reel (R suffix) | Tray | Tape & Reel | Tape & Reel | Tray |
| Drop-in Compatibility | Reference part (64-QFN MLF) | 100% pin-to-pin, identical die | 100% pin-to-pin, 5V only | Same footprint, reduced I/O - verify pin map | Same die, different package - board redesign needed |
Key Differentiators
- Widest voltage range in the 64-QFN ATmega128 group (vs ATMEGA128-16MUR)
- Reel packaging for automated assembly (vs ATMEGA128L-8MU)
- Full 53-I/O ATmega128 pin map retained (vs ATMEGA1281V-8MUR)
Design Notes
The 64-QFN (MLF) package requires the central exposed pad to be soldered to a PCB ground plane. Design the land pattern with a center pad of approximately 5.5x5.5 mm patterned into 3x3 or 4x4 segments with thermal vias (0.3mm, filled or plugged) to the ground layers. This pad is the primary ground return; an unsoldered center pad causes intermittent operation, elevated ground bounce, and ADC noise. Follow the IPC-recommended MLF land pattern in Microchip's package drawing for the MLF-64 9x9 mm outline.
Decouple each VCC/GND pair with 100nF ceramic capacitors placed within 2-3mm of the pins, plus a 4.7-10uF bulk capacitor near the supply entry. The L-grade part tolerates 2.7V minimum, so enable the internal brown-out detector (BOD) at 2.7V via fuse bits to prevent flash/EEPROM corruption during slow supply decay. If your rail can dip below 2.7V during transients, use the 4.0V BOD level or add supply hold-up capacitance. Estimated: a 10uF hold-up cap with 10mA load gives roughly 1ms of ride-down time per 100mV of headroom.
When replacing an ATmega103 on legacy boards, note the differences documented in Microchip application note 'Replacing ATmega103 by ATmega128': fuse-bit defaults, register address differences, and the need to program the M103C (ATmega103 compatibility) fuse for transparent migration. Also verify that your programmer supports the 64-QFN device - ISP programming shares SPI pins, so ensure SPIEN fuse is enabled and reset is held low during programming. Do not clock the L-grade above 8MHz; this violates the speed-vs-voltage specification.
Keep the crystal (or ceramic resonator) within 10mm of XTAL1/XTAL2 with short ground-guard traces, and place 100nF on AVCC with an LC filter (10uH + 100nF) between AVCC and VCC when ADC accuracy matters. Route JTAG traces away from switching nodes; JTAG is also usable as four extra GPIOs after disabling via the JTAGEN fuse, but leave the header populated during development for on-chip debug.
Compliance Information
Compliance status not stated in provided web data; Microchip standard ATmega128 product family is generally RoHS-compliant, but verify on the official Microchip product page before release.
