ATMEGA64L-8MUR - 8MHz AVR MCU 64KB Flash | Microchip
MPN: ATMEGA64L-8MUR ✗ End of Life| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $8.52 | $8.52 |
| 10 | $7.67 | $76.70 |
| 100 | $6.44 | $644.00 |
| 500 | $5.78 | $2,890.00 |
| 1,000 | $5.16 | $5,160.00 |
ATMEGA64L-8MUR Overview
An 8-bit microcontroller (MCU) is a self-contained computing chip that integrates a processor core, non-volatile program memory, static RAM, and peripherals such as timers, ADCs, and serial interfaces on a single die. Within the power-management and embedded-systems hierarchy, the MCU sits at the control layer above discrete logic and below application processors, executing one instruction per clock cycle in the AVR enhanced RISC architecture for near-1 MIPS per MHz performance.
Key features include the AVR RISC core with 130 powerful instructions (most single-cycle), 32 x 8 general-purpose working registers, fully static operation, and dual programmable serial USARTs. The 64 KB self-programmable Flash supports bootloader firmware updates, while the JTAG interface (IEEE compliant, on-chip debug and boundary scan) enables in-circuit debugging. Two 8-bit and two 16-bit timers with PWM, an 8-channel 10-bit ADC, byte-oriented Two-Wire Interface (I2C), SPI, and an analog comparator round out the peripheral set.
The ATmega64L 'L' variant is characterized for operation down to 2.7 V and up to 8 MHz, allowing single-supply 3.3 V or 5 V designs. Advanced RISC Harvard architecture with separate instruction and data buses achieves C-code density close to assembly. Power management includes six sleep modes and an on-chip Brown-out detector for supply-glitch resilience.
Typical applications include industrial control panels, metering systems, building automation nodes, and battery-powered instrumentation where the 53 I/O lines and dual USARTs eliminate external glue logic. Per Microchip, this is a mature product not recommended for new designs; the ATmega64A is the designated replacement.
Design consideration: keep ADC channels free of high-current PWM switching by careful PCB routing, and always enable the Brown-out detector below 4.5 V supplies.
This page synthesizes distributor pricing tiers, drop-in alternatives, pinout data, and practical design notes not found in the manufacturer datasheet.
Drop-in alternatives for ATMEGA64L-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 ATMEGA64L-8MUR (same form factor and footprint) — differing in Package, Supply Voltage Range, SRAM Size, EEPROM Size, Program Memory Size.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
ATMEGA64A-MUR
✅ Drop-In✓ In Stock
$4.42 / Unit
View Datasheet →ATMEGA64L-8MJ
✅ Drop-In ⚠️ 参数待验证✓ In Stock
$5.31 / Unit
View Datasheet →ATMEGA649A-MU
✅ Drop-In ⚠️ 参数待验证✓ In Stock
$4.42 / Unit
View Datasheet →ATMEGA649P-MUR
✅ Drop-In ⚠️ 参数待验证✓ In Stock
$5.1 / Unit
View Datasheet →ATMEGA645-16MUR
✅ Drop-In ⚠️ 参数待验证✓ In Stock
$3.35 / Unit
View Datasheet →ATMEGA128L-8MN
✅ Drop-In✓ In Stock
$7.68 / Unit
View Datasheet →ATMEGA64L-8MUR Maximum Ratings & Electrical Characteristics
| Core Processor | AVR |
| Core Size | 8-Bit |
| Speed | 8 MHz |
| Program Memory Size | 64 KB (32K x 16) FLASH |
| RAM Size | 4 KB SRAM |
| EEPROM Size | 2 KB |
| Number of I/O | 53 |
| Supply Voltage Range | 2.7 V to 5.5 V (L version) |
| Operating Temperature | -40C to +85C |
| Package | 64-QFN (9x9 mm) MLF |
| Mounting Type | Surface Mount |
| Peripherals | Brown-out Detect/Reset, POR, PWM, WDT |
| Connectivity | I2C (TWI), SPI, UART/USART x2 |
| Data Converters | 8-channel 10-bit ADC |
| Oscillator Type | External (XTAL) |
| Program Memory Type | In-System Programmable FLASH |
| Timers | Two 8-bit, Two 16-bit |
| JTAG | Yes (on-chip debug and boundary scan) |
| Architecture | Advanced RISC, 130 instructions, 32 x 8 registers |
ATMEGA64L-8MUR Pin Configuration
| Pin 1 | PE0 (RXD0/PDI) — Port E bit 0 / USART0 Receive |
| Pin 2 | PE1 (TXD0/PDO) — Port E bit 1 / USART0 Transmit |
| Pin 3 | PE2 (XCK0/AIN0) — Port E bit 2 / USART0 clock / Analog comparator negative input |
| Pin 4 | PE3 (AIN1/OC0) — Port E bit 3 / Analog comparator positive input / Timer0 output compare |
| Pin 5 | PE4 (OC3B/INT4) — Port E bit 4 / Timer3 output compare B / External interrupt 4 |
| Pin 6 | PE5 (OC3C/INT5) — Port E bit 5 / Timer3 output compare C / External interrupt 5 |
| Pin 7 | PE6 (T3/INT6) — Port E bit 6 / Timer3 clock input / External interrupt 6 |
| Pin 8 | PE7 (ICP3/INT7/CLKO) — Port E bit 7 / Timer3 input capture / External interrupt 7 / Clock output |
| Pin 9 | VCC — Digital supply voltage |
| Pin 10 | GND — Ground |
| Pin 11 | PA0 (AD0) — Port A bit 0 / External memory address/data line 0 |
| Pin 12 | PA1 (AD1) — Port A bit 1 / External memory address/data line 1 |
| Pin 13 | PA2 (AD2) — Port A bit 2 / External memory address/data line 2 |
| Pin 14 | PA3 (AD3) — Port A bit 3 / External memory address/data line 3 |
| Pin 15 | PA4 (AD4) — Port A bit 4 / External memory address/data line 4 |
| Pin 16 | PA5 (AD5) — Port A bit 5 / External memory address/data line 5 |
| Pin 17 | PA6 (AD6) — Port A bit 6 / External memory address/data line 6 |
| Pin 18 | PA7 (AD7) — Port A bit 7 / External memory address/data line 7 |
| Pin 19 | GND — Ground |
| Pin 20 | VCC — Digital supply voltage |
| Pin 21 | PB0 (SS) — Port B bit 0 / SPI Slave Select |
| Pin 22 | PB1 (SCK) — Port B bit 1 / SPI Serial Clock |
| Pin 23 | PB2 (MOSI) — Port B bit 2 / SPI Master Out Slave In |
| Pin 24 | PB3 (MISO) — Port B bit 3 / SPI Master In Slave Out |
| Pin 25 | PB4 (OC0) — Port B bit 4 / Timer0 output compare PWM |
| Pin 26 | PB5 (OC1A) — Port B bit 5 / Timer1 output compare A PWM |
| Pin 27 | PB6 (OC1B) — Port B bit 6 / Timer1 output compare B PWM |
| Pin 28 | PB7 (OC2/OC1C) — Port B bit 7 / Timer2 or Timer1 output compare C PWM |
| Pin 29 | PF0 (ADC0) — Port F bit 0 / ADC channel 0 |
| Pin 30 | PF1 (ADC1) — Port F bit 1 / ADC channel 1 |
| Pin 31 | PF2 (ADC2) — Port F bit 2 / ADC channel 2 |
| Pin 32 | PF3 (ADC3) — Port F bit 3 / ADC channel 3 |
| Pin 33 | PF4 (ADC4/TCK) — Port F bit 4 / ADC channel 4 / JTAG Test Clock |
| Pin 34 | PF5 (ADC5/TMS) — Port F bit 5 / ADC channel 5 / JTAG Test Mode Select |
| Pin 35 | PF6 (ADC6/TDO) — Port F bit 6 / ADC channel 6 / JTAG Test Data Out |
| Pin 36 | PF7 (ADC7/TDI) — Port F bit 7 / ADC channel 7 / JTAG Test Data In |
| Pin 37 | GND — Ground |
| Pin 38 | VCC — Digital supply voltage |
| Pin 39 | PG0 (WR) — Port G bit 0 / External memory write strobe |
| Pin 40 | PG1 (RD) — Port G bit 1 / External memory read strobe |
| Pin 41 | PC0 (A8) — Port C bit 0 / External memory address line 8 |
| Pin 42 | PC1 (A9) — Port C bit 1 / External memory address line 9 |
| Pin 43 | PC2 (A10/TCK) — Port C bit 2 / Address line 10 / JTAG Test Clock |
| Pin 44 | PC3 (A11/TMS) — Port C bit 3 / Address line 11 / JTAG Test Mode Select |
| Pin 45 | PC4 (A12/TDO) — Port C bit 4 / Address line 12 / JTAG Test Data Out |
| Pin 46 | PC5 (A13/TDI) — Port C bit 5 / Address line 13 / JTAG Test Data In |
| Pin 47 | PC6 (A14/TOSC1) — Port C bit 6 / Address line 14 / Timer oscillator input |
| Pin 48 | PC7 (A15/TOSC2) — Port C bit 7 / Address line 15 / Timer oscillator output |
| Pin 49 | PG2 (ALE) — Port G bit 2 / External memory address latch enable |
| Pin 50 | TOSC2 (RTC) — Timer oscillator output (asynchronous Timer2) |
| Pin 51 | TOSC1 (RTC) — Timer oscillator input (asynchronous Timer2) |
| Pin 52 | VCC — Digital supply voltage |
| Pin 53 | GND — Ground |
| Pin 54 | PD0 (SCL/INT0) — Port D bit 0 / TWI clock / External interrupt 0 |
| Pin 55 | PD1 (SDA/INT1) — Port D bit 1 / TWI data / External interrupt 1 |
| Pin 56 | PD2 (TXD1/INT2) — Port D bit 2 / USART1 transmit / External interrupt 2 |
| Pin 57 | PD3 (RXD1/INT3) — Port D bit 3 / USART1 receive / External interrupt 3 |
| Pin 58 | PD4 (ICP1) — Port D bit 4 / Timer1 input capture |
| Pin 59 | PD5 (XCK1) — Port D bit 5 / USART1 clock |
| Pin 60 | PD6 (T1) — Port D bit 6 / Timer1 external clock input |
| Pin 61 | PD7 (T2) — Port D bit 7 / Timer2 external clock input |
| Pin 62 | RESET — Reset input (active low); source of reset |
| Pin 63 | XTAL2 — Inverted oscillator output |
| Pin 64 | XTAL1 — Inverted oscillator input / external clock input |
Typical Applications
ATMEGA64L-8MUR is suitable for 6 applications: Industrial Control and Automation, Battery-Powered Metering and Instrumentation, Building Automation and HVAC Controllers, Embedded Networking and Protocol Gateways, Motor Control and PWM Actuation, Legacy Product Sustaining and ATmega103 PCB Migration.
Industrial Control and Automation
The ATMEGA64L-8MUR suits industrial control panels and PLC-style I/O nodes because its 53 GPIO lines, dual USARTs, and 8-channel 10-bit ADC allow sensing, actuation, and Modbus-style RS-485 communication without external glue logic. Its 5 V-tolerant supply range (2.7 V to 5.5 V) matches legacy 24 V industrial rails stepped down to 5 V, while the Brown-out detector and watchdog timer provide fail-safe reset behavior required in factory environments. Placed on the control PCB running at 8 MHz, it delivers roughly 8 MIPS, sufficient for PID loops and protocol handling. The trade-off versus a 32-bit MCU is lower compute headroom, but code determinism and single-cycle bit manipulation simplify real-time interrupt handling.
Recommended
Battery-Powered Metering and Instrumentation
For utility meters, data loggers, and handheld instruments, the ATMEGA64L-8MUR's six sleep modes and microamp-level Power-down current extend battery life substantially. Its 8-channel 10-bit ADC samples voltage, current, and temperature channels, while 2 KB EEPROM stores calibration constants and billing counters that survive power loss. Running from a 3 V lithium cell at 8 MHz or lower, the AVR core executes sampling loops with predictable single-cycle timing. A typical design wakes via watchdog or external interrupt, samples, computes, writes EEPROM, and returns to Power-down, achieving multi-year battery life. Compared to the ATMEGA649P-MUR picoPower variant, sleep current is higher, so for extreme battery budgets the P-variant is the better fit on the same footprint.
Recommended
Building Automation and HVAC Controllers
In building automation nodes, thermostats, and HVAC zone controllers, the ATMEGA64L-8MUR integrates TWI (I2C) for sensor networks, SPI for external flash or displays, and two USARTs for backbone communication and service ports. The 64 KB Flash accommodates a protocol stack plus a bootloader for field firmware updates over the serial line, eliminating recalls. PWM outputs from its 8-bit and 16-bit timers drive damper motors, fan control, and heater SSRs directly through driver stages. Operating at 3.3 V or 5 V simplifies mixed-sensor designs. Its mature errata history and long Microchip documentation trail reduce qualification risk in commercial building products, though new designs should adopt the pin-compatible ATMEGA64A-MUR for lifecycle assurance.
Recommended
Embedded Networking and Protocol Gateways
The dual USART architecture of the ATMEGA64L-8MUR makes it effective as a serial protocol converter or gateway, translating between RS-232 field devices and RS-485 backbone segments. With 4 KB SRAM, packet buffers for framing, CRC, and retransmission logic fit comfortably, and 64 KB Flash holds multiple protocol stacks with room for a bootloader. Hardware support for multi-processor communication mode on the USART simplifies multi-drop addressing. At 8 MHz, sustained throughput of a few hundred kilobaud per port is realistic with interrupt-driven ring buffers. Designs needing higher bandwidth or CAN should step to AT90CAN-family parts, but for simple serial bridging, this AVR reduces BOM cost and firmware complexity versus a 32-bit solution.
Recommended
Motor Control and PWM Actuation
The ATMEGA64L-8MUR drives small DC motors, stepper drivers, and actuator systems using its two 8-bit timers and two 16-bit timers with multiple PWM channels and input-capture capability. The 16-bit timer input capture enables precise measurement of encoder or hall-sensor periods for closed-loop speed control, while output-compare channels generate phase-correct or fast PWM at carrier frequencies suitable for MOSFET half-bridge drivers. Five-volt GPIO directly interfaces with gate drivers and logic-level MOSFETs. The ADC reads current-shunt feedback for overcurrent protection in software. For robust designs, keep the PWM switching loops physically separated from the ADC reference on the PCB and use the comparator input for fast hardware-level fault latching.
Recommended
Legacy Product Sustaining and ATmega103 PCB Migration
A principal remaining use of the ATMEGA64L-8MUR is sustaining existing product lines and migrating legacy ATmega103-based PCBs: per the Atmel-2490 datasheet, the ATmega64 is 100 percent pin compatible with the ATmega103 and drops onto existing boards. Repair, refurbishment, and spares manufacturing for industrial equipment installed bases frequently need this exact MLF64 part. Firmware may require register-level adjustments documented in Microchip migration application notes, and the JTAG port enables in-system reprogramming of aging units in the field. Because the part is mature, procurement teams should buy the pin-compatible ATMEGA64A-MUR for future builds and reserve the L-suffix part for form-fit-function-restricted service contracts where requalification is not an option.
Recommended
Recommended Products Summary
Engineering reference data for ATMEGA64L-8MUR — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | ATMEGA64A-MUR | ATMEGA649A-MU | ATMEGA645-16MUR | ATMEGA128L-8MN |
|---|---|---|---|---|---|
| Package | 64-QFN (9x9 mm) | 64-QFN (9x9 mm) - same | 64-QFN (9x9 mm) - same | 64-QFN (9x9 mm) - same | 64-QFN (9x9 mm) - same |
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Max Speed | 8 MHz | 16 MHz (5V) / 8 MHz (2.7V) | 8 MHz (L grade) | 16 MHz (5V) | 8 MHz |
| Flash Memory | 64 KB | 64 KB | 64 KB | 64 KB | 128 KB |
| SRAM | 4 KB | 4 KB | 4 KB | 4 KB | 8 KB |
| EEPROM | 2 KB | 2 KB | 2 KB | 2 KB | 4 KB |
| General Purpose I/O | 53 | 53 | fewer (pins shared with LCD driver) | fewer (pins shared with LCD driver) | 53 |
| Special Features | JTAG, 2x USART, 10-bit ADC, External memory bus | identical + updated process (successor) | segment LCD controller added | LCD controller + 16 MHz | double memory, extended register map |
| Lifecycle Status | Mature / NRND (replaced by ATmega64A) | Active | Active | Active | Active family (ATmega128A) |
Key Differentiators
- Guaranteed 2.7 V low-voltage operation (vs ATMEGA645-16MUR)
- 53 free general-purpose I/O lines (vs ATMEGA649A-MU)
- Cheapest 64 KB entry point in the footprint (vs ATMEGA128L-8MN)
- Honest trade-off: NRND lifecycle status (vs ATMEGA64A-MUR)
Design Notes
The ATMEGA64L-8MUR supports 2.7 V to 5.5 V, but speed must be derated at low voltage: 8 MHz is the L-grade maximum across the full range, and pushing beyond the speed-versus-voltage curve in the Atmel-2490 datasheet voids guaranteed operation. Enable the Brown-out detector with a threshold appropriate to your rail (e.g., BOD at 2.7 V for 3.3 V systems) so EEPROM/Flash writes never occur during brown-out. Estimate: at 8 MHz, 3 V, active-mode current is on the order of a few mA per the datasheet; use sleep modes and the Power Reduction registers to cut average consumption dramatically in battery designs.
The 64-QFN (9x9 mm) MLF package has a large exposed die paddle on the underside that must be soldered to a grounded copper pour with an array of thermal vias - this is the primary ground return and heat path. The Atmel-2490 datasheet documents the recommended land pattern. Decouple each VCC pin (9, 20, 38, 52) with 100 nF ceramic capacitors placed within 2 mm of the pin, plus one bulk 4.7 uF to 10 uF capacitor per supply domain. Route the XTAL1/XTAL2 crystal traces short and guarded, and keep the TOSC 32.768 kHz traces away from PWM switching nodes.
Three common traps: (1) JTAG shares pins PF4-PF7 (ADC4-ADC7) - the factory-enabled JTAGEN fuse blocks those ADC channels; disable JTAG via fuse or the double-write JTD bit if you need all eight ADC inputs. (2) PC2-PC7 carry both external-memory address lines and JTAG/TOSC functions - confirm the fuse settings before release programming. (3) This device is Microchip NRND; design-in the ATMEGA64A-MUR for new builds. Also remember AVCC must be connected even if the ADC is unused, per datasheet minimum wiring requirements.
When using the external memory bus (PA0-PA7 multiplexed address/data with ALE on PG2), keep the bus stubs short and add series termination of 22-33 ohm on fast edges to limit ringing at 8 MHz system clocks with fast I/O slew. For the dual USARTs on RS-485 backbones, place the transceiver within 20 mm of the MCU pins, bias the fail-safe resistor network, and isolate grounds properly across cable runs. Per Microchip AVR hardware design application guidance, unused GPIO should be configured as inputs with pull-ups enabled or driven low as outputs to prevent floating-pin EMI.
Compliance Information
RoHS/lead-free status inferred from current Microchip commercial-grade ATmega64 packaging (lead-free MLF). REACH, halogen-free, and conflict-minerals declarations not present in the provided web data - verify on Microchip's product compliance portal.
