ATMEGA64A-MUR - AVR 8-bit MCU 64KB Flash 16MHz QFN-64 | Microchip
MPN: ATMEGA64A-MUR ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $6.92 | $6.92 |
| 10 | $6.23 | $62.30 |
| 100 | $5.54 | $554.00 |
| 500 | $4.98 | $2,490.00 |
| 1,000 | $4.42 | $4,420.00 |
ATMEGA64A-MUR Overview
An 8-bit microcontroller (MCU) is a self-contained computing chip integrating a processor core, program memory, data memory, and peripherals on a single die, sitting at the device level of the embedded systems hierarchy (embedded system -> MCU -> AVR core -> RISC CPU). The AVR ATmega family from Microchip uses an advanced RISC architecture with Harvard memory mapping, allowing most instructions to execute in a single clock cycle.
Key features include the AVR advanced RISC core with 130 powerful instructions, 32 general-purpose working registers executing most instructions in one cycle, in-system self-programmable Flash with read-while-write capability, a real-time counter, and four flexible timer/counters supporting PWM generation and input capture. The wide supply range of 2.7V to 5.5V supports both 3.3V and 5V designs, and the internal oscillator option reduces external component count.
Architecturally, the ATmega64A executes pipelined single-cycle instructions from Flash while a separate small EEPROM retains non-volatile parameters, and the SRAM data space is extended via external memory interfacing. JTAG/ISP programming support enables in-field firmware updates. The A-suffix die is Microchip's refreshed ATmega64 process node with improved reliability over the original ATmega64.
Typical applications include industrial automation controllers, sensor hubs and data loggers, LED and motor control, HVAC and building control systems, and legacy ATmega103 board redesigns, since the ATmega64A is 100% pin compatible with the ATmega103 and can replace it on existing printed circuit boards.
Design consideration: operate within the industrial temperature grade and verify 16MHz timing at the low end of the 2.7V-5.5V supply range, as maximum safe frequency depends on VCC; decouple all supply pins with 100nF ceramics close to the exposed pad.
This page synthesizes distributor pricing, drop-in alternatives, pinout guidance, and practical design notes not found in the manufacturer datasheet.
Drop-in alternatives for ATMEGA64A-MUR — 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 ATMEGA64A-MUR (same form factor and footprint) — differing in Package, Debug Interface, Core Architecture, SRAM Size, Supply Voltage Range.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
ATMEGA649P-MUR
✅ Drop-In ⚠️ 参数待验证✓ In Stock
$5.1 / Unit
View Datasheet →ATMEGA649A-MU
✅ Drop-In ⚠️ 参数待验证✓ In Stock
$4.42 / Unit
View Datasheet →ATMEGA64-16MI
✅ Drop-In ⚠️ 参数待验证✓ In Stock
$4.48 / Unit
View Datasheet →AT90USB646-MUR
✅ Drop-In📋 Reference alternative (not in catalog)
ATMEGA64A-MU
✅ Drop-In📋 Reference alternative (not in catalog)
ATMEGA64A-MUR Maximum Ratings & Electrical Characteristics
| Core Architecture | AVR 8-bit RISC |
| Program Memory Size | 64KB (32K x 16) Flash |
| Program Memory Type | ISP Flash, read-while-write |
| EEPROM Size | 2KB |
| SRAM Size | 4KB (4K x 8) |
| Maximum Clock Speed | 16 MHz |
| Supply Voltage Range | 2.7 V to 5.5 V |
| Number of I/O | 53 |
| General Purpose Working Registers | 32 |
| Instruction Set | 130 powerful instructions, most single-cycle |
| Timers/Counters | 4 flexible timer/counters plus real-time counter |
| Oscillator Type | Internal |
| Package / Case | 64-VFQFN Exposed Pad (9x9 mm) |
| Mounting Type | Surface Mount |
| Temperature Grade | Industrial (-40C to +85C) |
| Packaging | Tape & Reel |
| Programming Interface | ISP (In-System Programmable), JTAG |
ATMEGA64A-MUR 64-vfqfn exposed pad (9x9 mm) Pin Configuration Guide
Pin configuration for ATMEGA64A-MUR (64-vfqfn exposed pad (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 ATMEGA64A-MUR.
Refer to the datasheet for full pin configuration.
Typical Applications
ATMEGA64A-MUR is suitable for 6 applications: Industrial Automation Controllers, Sensor Hubs and Data Loggers, Motor Control and LED Drivers, Legacy ATmega103 Board Redesign, HVAC and Building Control, Consumer and Instrumentation Products.
Industrial Automation Controllers
The ATMEGA64A-MUR fits industrial automation nodes because its industrial -40C to +85C grade, 5.5V-tolerant 2.7V-5.5V supply, and 53 I/O lines drive relays, sensors, and operator interfaces directly without level shifting. Its four flexible timer/counters generate multiple hardware PWM channels for motor and heater control, while two USARTs and SPI/TWI interfaces link PLC backplanes and HMI panels. The 64KB ISP Flash accommodates substantial ladder-logic or protocol firmware, and 2KB EEPROM stores configuration through power cycles. Placed on a 5V rail with 100nF decoupling per supply pin and the exposed pad soldered to ground pour, the MCU sustains noisy factory-floor environments; the read-while-write Flash enables field firmware updates over a bootloader without halting time-critical ISR processing.
Recommended
Sensor Hubs and Data Loggers
For sensor aggregation and data logging, the ATMEGA64A-MUR combines a 10-bit-class analog front end environment with SPI, TWI, and UART links to external ADCs, EEPROM, and real-time clocks. The 4KB SRAM buffers sampling windows for post-processing, and the 2KB EEPROM retains calibration coefficients across power loss. With its internal RC oscillator the hub can run crystal-free in cost-sensitive nodes, switching to an external crystal when precise sample-rate timestamps are required. The 64-QFN 9x9 mm exposed-pad package offers compact board area with good thermal grounding for sealed enclosures. Sleep modes of the AVR core keep average current low in battery-backed loggers, while the 16MHz RISC core provides ample headroom for burst signal processing between low-power duty-cycled acquisition periods.
Recommended
Motor Control and LED Drivers
The ATMEGA64A-MUR generates multi-channel hardware PWM from its four timer/counters, making it a strong MCU for motor drives, dimmable LED luminaires, and actuator controllers. At 16MHz, PWM resolution and interrupt latency support closed-loop current or speed control at practical loop rates, and the hardware input-capture pins measure encoder or hall-sensor feedback without software jitter. The 53 I/O lines interface MOSFET gate drivers, current-sense amplifiers, and fault-feedback lines in one package. Operating from 5V eases direct interfacing with gate-driver logic thresholds common in industrial drives. Design the power stage on a separate PCB area with the MCU's exposed pad tied to a clean analog ground, and route timer PWM outputs away from sense lines to protect ADC accuracy from switching transients.
Recommended
Legacy ATmega103 Board Redesign
Microchip explicitly documents that the ATmega64A is 100% pin compatible with the ATmega103 and can replace it on current printed circuit boards, making ATMEGA64A-MUR the standard rescue part for obsolete ATmega103 sockets in the same 64-QFN/TQFP footprints. Products in long service life markets - industrial controls, agricultural equipment, medical consumables - can refresh their silicon without a PCB respin. The application note 'Replacing ATmega103 by ATmega64A' details fuse, register, and peripheral behavioral differences to address in firmware. Since the ATmega103 is long discontinued, migrating to the active ATMEGA64A-MUR restores a fully supported, RoHS-compliant supply chain with 64KB ISP Flash, 2KB EEPROM, and 16MHz performance, while retaining the original board layout, connectors, and tooling investments.
Recommended
HVAC and Building Control
Building automation equipment - thermostat controllers, damper actuators, fan coil units - benefits from the ATMEGA64A-MUR's wide 2.7V-5.5V operation, industrial temperature rating, and abundant I/O for keypads, displays, and triac/relay outputs. TWI (I2C) connects temperature and humidity sensors, UART links to RS-485 transceivers for Modbus networks, and timer PWM drives proportional valve actuators. The 2KB EEPROM stores setpoint tables and service counters that must survive power interruptions, and the internal oscillator supports crystal-free board builds where cost dominates. In HVAC enclosures with wide ambient swings, the industrial -40C to +85C grade plus the QFN exposed-pad thermal path keep junction temperatures safe without heatsinking, while the AVR's brown-out detector and watchdog timer guard against supply dips in shared building power systems.
Recommended
Consumer and Instrumentation Products
Mid-range consumer appliances and test instruments use the ATMEGA64A-MUR where 8-bit simplicity, 64KB of code space, and rich peripherals outperform 32-bit parts on cost and time-to-market. The two USARTs serve barcode modules and printers, SPI drives graphical LCD or OLED panels, and timer PWM produces buzzer tones and backlight dimming. The internal oscillator with calibration bytes simplifies single-chip designs, while an external crystal is added for timekeeping instruments. The 64-QFN 9x9 mm package suits compact handheld enclosures, and 5V operation directly drives LED segments and legacy logic. Development on Microchip Studio with AVR ISP or JTAG tooling keeps firmware iteration fast, and the read-while-write Flash enables feature updates via bootloader in shipped units - reducing warranty-return rework for feature refresh cycles.
Recommended
Recommended Products Summary
Engineering reference data for ATMEGA64A-MUR — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | ATMEGA649P-MUR | AT90USB646-MUR | ATMEGA64-16MI |
|---|---|---|---|---|
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology (Atmel legacy) |
| Package | 64-QFN (9x9 mm) VFQFN exposed pad | 64-QFN (9x9 mm) - same | 64-QFN - same | 64-QFN - same |
| Flash Memory | 64KB (32K x 16) ISP | 64KB | 64KB | 64KB |
| SRAM | 4KB | 4KB | 4KB | 4KB |
| Max Clock Speed | 16 MHz | 16 MHz | 16 MHz | 16 MHz |
| Supply Voltage | 2.7 V to 5.5 V | 1.8 V to 5.5 V (P-version low-voltage support) | 2.7 V to 5.5 V | 4.5 V to 5.5 V |
| USB Controller | No | No | Yes, full-speed USB 2.0 device | No |
| LCD Controller | No | Yes, segment LCD driver | No | No |
| Lifecycle Status | Active | Active | Active | Legacy / not recommended for new designs |
Key Differentiators
- Lowest-risk legacy drop-in: documented ATmega103 replacement (vs AT90USB646-MUR)
- Cost-efficient non-USB 8-bit solution (vs AT90USB646-MUR)
- Active, refreshed A-version silicon (vs ATMEGA64-16MI)
- Core-only simplicity vs LCD-integrated siblings (vs ATMEGA649P-MUR)
Design Notes
Decouple every VCC/AVCC pin pair with a 100nF ceramic capacitor placed within 2-3 mm of the pin, plus one bulk 10uF capacitor near the 64-QFN. Solder the exposed pad to a solid ground pour with an array of vias - it is the primary ground and thermal path in the VFQFN package. When running at 16MHz near the low end of the 2.7V-5.5V range, check the AVR voltage-frequency derating curve in the Microchip ATmega64A datasheet; if marginal, enable the internal RC oscillator at a lower frequency or raise the rail. Estimated: at 5V/16MHz and 15mA active current, power dissipation is only 75mW, so no heatsinking is needed.
Fuse settings are the number-one field failure cause on ATmega parts: an incorrect clock-source fuse (e.g., selecting external clock when only the internal RC is fitted) can appear to brick the device, requiring a high-voltage parallel programmer for recovery. Verify SPIEN, JTAGEN, and clock fuses against the Microchip ATmega64A datasheet fuse tables before production programming. Also note that JTAG shares pins PC2-PC5 with port C - if you need all 53 I/O, disable JTAG via fuse or software and free four pins for GPIO.
Route the XTAL1/XTAL2 crystal traces short (under 10 mm) and guard them with ground; keep the ISP/JTAG header traces away from high-dV/dt switching nodes to prevent corruption during in-system programming. For designs migrating from ATmega103, confirm that the PC2-PC5 JTAG function and any ATmega103-compatibility (M103C) fuse state match your original board behavior - the compatibility fuse changes port behavior at reset and is a classic migration bug documented in Microchip's 'Replacing ATmega103 by ATmega64A' application note.
When using both USARTs and SPI simultaneously at high baud rates, prioritize interrupt latency by keeping ISRs short and using the UART double-speed mode to relax timing. The AVR's single-cycle 32-register architecture handles typical 16MHz bit-banging well, but for external memory (XMEM) expansions keep bus trace lengths under about 100mm and add 22-33 ohm series resistors on address/data lines to control ringing on 5V CMOS edges.
Compliance Information
RoHS/lead-free status per standard Microchip leaded-free suffix convention for -MUR tape-and-reel parts; REACH and halogen-free status not stated in provided data - verify on Microchip product page.
