ATMEGA64L-8AQ - 8-Bit AVR MCU, 64KB Flash, 8MHz TQFP-64 | Microchip
MPN: ATMEGA64L-8AQ ✗ End of Life| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $10.68 | $10.68 |
| 10 | $9.9 | $99.00 |
| 100 | $8.95 | $895.00 |
| 500 | $8.2 | $4,100.00 |
| 1,000 | $7.5 | $7,500.00 |
ATMEGA64L-8AQ Overview
A microcontroller (MCU) integrates a processor core, program memory, data memory, and peripherals on a single chip, forming the lowest level of the embedded-system hierarchy: microcontroller -> embedded processor -> integrated circuit -> semiconductor. AVR is a RISC (reduced instruction set computer) architecture in which most of the 130 powerful instructions execute in a single clock cycle, and 32 x 8-bit general-purpose working registers are directly connected to the ALU, so the ATMEGA64L-8AQ achieves close to 1 MIPS per MHz - roughly 8 MIPS throughput at its maximum 8 MHz clock when powered at 3V (the L suffix, per Microchip data).
Key features include the 64KB self-programming Flash with a boot-loader section for in-system reprogramming, an 8-channel 10-bit ADC for direct analog sensor interface, a JTAG interface for on-chip debugging and boundary scan, two hardware USARTs, SPI, TWI (I2C), three timers with PWM outputs, and an external memory interface allowing expansion of up to 64KB of external SRAM.
Technically, the fully static core lets the clock be stopped without losing register contents, while multiple sleep modes (idle, ADC noise reduction, power-save, standby, extended standby) cut power draw dramatically in battery-operated designs. The self-programming capability enables field firmware updates without an external programmer.
Typical applications include industrial control panels, metering instruments, building automation nodes, and legacy embedded systems that require the proven ATmega64 peripheral set with low-voltage 3V operation.
Design consideration: the L variant is specified for 0-8 MHz at 2.7-5.5V; for new designs Microchip recommends the newer ATmega64A family, as the ATmega64L is a mature, not-recommended-for-new-designs product.
This page synthesizes verified distributor pricing, drop-in alternative cross-references, and practical design notes not found in the manufacturer datasheet.
Drop-in alternatives for ATMEGA64L-8AQ — 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-8AQ (same form factor and footprint) — differing in Package, Timers/Counters, ADC, EEPROM, Program Memory Size.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
ATMEGA64A-AUR
✅ Drop-In✓ In Stock
$4.1 / Unit
View Datasheet →ATMEGA64L-8AI
✅ Drop-In✓ In Stock
$6.7 / Unit
View Datasheet →ATMEGA64-16AU
✅ Drop-In✓ In Stock
$7.23 / Unit
View Datasheet →ATMEGA64A-MUR
✅ Drop-In✓ In Stock
$4.42 / Unit
View Datasheet →ATMEGA640V-8AU
✅ Drop-In✓ In Stock
$3.95 / Unit
View Datasheet →ATMEGA640-16AUR
✅ Drop-In✓ In Stock
$5.9 / Unit
View Datasheet →ATMEGA64L-8AQ Maximum Ratings & Electrical Characteristics
| Core Size | 8-Bit |
| Series | AVR ATmega64 |
| Maximum Clock Frequency | 8 MHz |
| Program Memory Size | 64 KB (32K x 16) Flash |
| EEPROM Size | 2 KB |
| SRAM Size | 4 KB |
| ADC Resolution | 10-bit |
| Number of ADC Channels | 8 |
| Core Architecture | AVR RISC, 130 instructions |
| General Purpose Registers | 32 x 8 |
| Debug Interface | JTAG (on-chip debug, boundary scan) |
| Communication Interfaces | 2x USART, SPI, TWI (I2C) |
| Operating Voltage | 2.7 V to 5.5 V (L grade) |
| Operating Temperature | -40C to +85C |
| Package | 64-TQFP (14x14 mm) |
| Mounting Type | Surface Mount |
| Life Cycle | Mature; not recommended for new designs (replaced by ATmega64A) |
ATMEGA64L-8AQ Pin Configuration
| Pin 1 | PEN — Programming enable (serial programming) |
| Pin 2 | PE0 — USART0 receive (RXD0) |
| Pin 3 | PE1 — USART0 transmit (TXD0) |
| Pin 4 | PE2 — USART0 clock (XCK0) / analog comparator input AIN0 |
| Pin 5 | PE3 — Timer3 output compare A (OC3A) / AIN1 |
| Pin 6 | PE4 — Timer3 output compare B (OC3B) / external interrupt INT4 |
| Pin 7 | PE5 — Timer3 output compare C (OC3C) / external interrupt INT5 |
| Pin 8 | PE6 — Timer3 clock input (T3) / external interrupt INT6 |
| Pin 9 | PE7 — Timer3 input capture (ICP3) / clock output (CLKO) / INT7 |
| Pin 10 | VCC — Digital supply voltage |
| Pin 11 | GND — Digital ground |
| Pin 12 | PG0 — External memory write strobe (WR) |
| Pin 13 | PG1 — External memory read strobe (RD) |
| Pin 14 | PC0 — External memory address line A8 / GPIO |
| Pin 15 | PC1 — External memory address line A9 / GPIO |
| Pin 16 | PC2 — External memory address line A10 / GPIO |
| Pin 17 | PC3 — External memory address line A11 / GPIO |
| Pin 18 | PC4 — External memory address line A12 / GPIO |
| Pin 19 | PC5 — External memory address line A13 / GPIO |
| Pin 20 | PC6 — External memory address line A14 / GPIO |
| Pin 21 | PC7 — External memory address line A15 (TOSC2) / GPIO |
| Pin 22 | AREF — ADC reference voltage |
| Pin 23 | AGND — Analog ground |
| Pin 24 | PF0 — ADC input channel 0 (ADC0) / GPIO |
| Pin 25 | PF1 — ADC input channel 1 (ADC1) / GPIO |
| Pin 26 | PF2 — ADC input channel 2 (ADC2) / GPIO |
| Pin 27 | PF3 — ADC input channel 3 (ADC3) / GPIO |
| Pin 28 | PF4 — ADC input channel 4 (ADC4) / JTAG test clock (TCK) |
| Pin 29 | PF5 — ADC input channel 5 (ADC5) / JTAG test mode select (TMS) |
| Pin 30 | PF6 — ADC input channel 6 (ADC6) / JTAG test data out (TDO) |
| Pin 31 | PF7 — ADC input channel 7 (ADC7) / JTAG test data in (TDI) |
| Pin 32 | GND — Ground |
| Pin 33 | VCC — Supply voltage |
| Pin 34 | PA0 — ADC0 / external memory address/data line AD0 / GPIO |
| Pin 35 | PA1 — ADC1 / external memory address/data line AD1 / GPIO |
| Pin 36 | PA2 — ADC2 / external memory address/data line AD2 / GPIO |
| Pin 37 | PA3 — ADC3 / external memory address/data line AD3 / GPIO |
| Pin 38 | PA4 — ADC4 / external memory address/data line AD4 / GPIO |
| Pin 39 | PA5 — ADC5 / external memory address/data line AD5 / GPIO |
| Pin 40 | PA6 — ADC6 / external memory address/data line AD6 / GPIO |
| Pin 41 | PA7 — ADC7 / external memory address/data line AD7 / GPIO |
| Pin 42 | PB0 — SPI slave select (SS) / GPIO |
| Pin 43 | PB1 — SPI clock (SCK) / GPIO |
| Pin 44 | PB2 — SPI master out slave in (MOSI) / GPIO |
| Pin 45 | PB3 — SPI master in slave out (MISO) / GPIO |
| Pin 46 | PB4 — Timer0 output compare (OC0) / PWM / GPIO |
| Pin 47 | PB5 — Timer1 output compare A (OC1A) / PWM / GPIO |
| Pin 48 | PB6 — Timer1 output compare B (OC1B) / PWM / GPIO |
| Pin 49 | PB7 — Timer2 output compare (OC2) / Timer1 output compare C (OC1C) / GPIO |
| Pin 50 | PD0 — USART1 receive (RXD1) / external interrupt INT0 / GPIO |
| Pin 51 | PD1 — USART1 transmit (TXD1) / external interrupt INT1 / GPIO |
| Pin 52 | PD2 — External interrupt INT2 (serial data in SDA) / GPIO |
| Pin 53 | PD3 — External interrupt INT3 (serial clock SCL) / GPIO |
| Pin 54 | PD4 — USART1 external clock (XCK1) / Timer1 input capture (ICP1) / GPIO |
| Pin 55 | PD5 — Timer1 external clock (T1) / GPIO |
| Pin 56 | PD6 — Timer1 input capture (ICP1) / GPIO |
| Pin 57 | PD7 — Timer2 output compare (OC2) / GPIO |
| Pin 58 | RESET — Reset input (active low) |
| Pin 59 | VCC — Supply voltage |
| Pin 60 | GND — Ground |
| Pin 61 | XTAL2 — Inverting oscillator output |
| Pin 62 | XTAL1 — Inverting oscillator input / external clock input |
| Pin 63 | PG2 — External memory address latch enable (ALE0) / GPIO |
| Pin 64 | PG3 — External memory address latch enable (ALE1) / GPIO |
Typical Applications
ATMEGA64L-8AQ is suitable for 6 applications: Industrial Control and Automation, Metering and Measurement Instruments, Building Automation Nodes, Legacy Embedded System Maintenance, Motor Control and PWM Drive, Human-Machine Interface Panels.
Industrial Control and Automation
The ATMEGA64L-8AQ fits industrial control panels and machine controllers because it combines an external memory interface, two hardware USARTs for Modbus-style RS-485 links, and a JTAG port for field diagnostics in one 64-TQFP device. Its 8-channel 10-bit ADC reads analog setpoint potentiometers and sensor loops directly, while Timer PWM outputs drive actuators and heater control. The -40C to +85C industrial temperature range covers unconditioned cabinets, and the fully static core tolerates clock gating for low standby power between production cycles. Placed on a 5V industrial rail with 0.1uF local decoupling, it runs reliably at its 8 MHz maximum with approximately 8 MIPS throughput, sufficient for sequential control logic, PID loops at low sample rates, and HMI button/LED scanning.
Recommended
Metering and Measurement Instruments
Energy meters, bench instruments, and data loggers benefit from the ATMEGA64L-8AQ's 8-channel 10-bit ADC with an internal reference option and 15 kSPS-class sampling, which directly digitizes voltage/current sense networks without an external converter. The 2KB EEPROM retains calibration constants and accumulated register values through power cycles, and the self-programming 64KB Flash allows remote firmware/calibration-table updates via bootloader. The L-grade 2.7V minimum supply supports battery-backup operation of the metering front end. Typical circuit: sense dividers into ADC0-ADC3, a USART line to the billing head, and SPI to an external EEPROM or display driver. JTAG-based boundary scan eases production test of the dense analog/digital mixed board.
Recommended
Building Automation Nodes
Room controllers, damper actuators, and access-control nodes use the ATMEGA64L-8AQ's TWI (I2C) interface to aggregate temperature and humidity sensors while its second USART handles RS-485 trunk communication. The 4KB SRAM comfortably buffers protocol stacks such as lightweight BACnet or Modbus RTU implementations, and 64KB Flash hosts the application plus bootloader for network firmware updates. Multiple sleep modes, including power-save with a 32.768 kHz TOSC crystal on the TOSC pins, let the node idle at microamp-level current between scheduled actions - important for battery-hybrid powered nodes. The 64-TQFP provides enough GPIO (53 I/O) to drive relays, LEDs, and keypads without port expanders, reducing BOM cost per node.
Recommended
Legacy Embedded System Maintenance
The primary ongoing role of the ATMEGA64L-8AQ is sustaining existing product lines whose firmware and PCBs were validated around the ATmega64L die. Because the part is marked mature/not-recommended-for-new-designs by Microchip, maintenance engineers should qualify the ATMEGA64A-AUR drop-in successor and stock bridging quantities of the original. The identical 64-TQFP footprint means no PCB respin, and AVR object compatibility means firmware compiles with the same AVR-GCC/AVR Studio toolchain. For critical spares procurement, verify date codes and buy from authorized distributors to avoid recycled or remarked parts, which are a known counterfeit risk on mature Atmel-family MCUs.
Recommended
Motor Control and PWM Drive
Small motor drives - DC fan controllers, stepper drivers, and BLDC commutation prototypes - leverage the ATmega64L's three timers producing multiple hardware PWM channels (OC0, OC1A/1B/1C, OC2, OC3A/3B/3C) with complementary control granularity. The 8-channel ADC supports speed-setting inputs and back-EMF or current-shunt feedback with the ADC noise-reduction sleep mode reducing conversion jitter. The 8 MHz L-grade clock is adequate for sensorless BLDC at low-to-medium mechanical speeds, and the JTAG interface permits cycle-accurate debugging of commutation interrupt routines, which is invaluable when tuning phase timing. Gate-driver inputs connect directly to PWM output pins through level-shifting if the power stage runs above 5V logic.
Recommended
Human-Machine Interface Panels
Operator panels with keypads and character or graphic displays exploit the ATMEGA64L-8AQ's large GPIO count (53 programmable I/O lines) in the compact 64-TQFP (14x14 mm) footprint. A matrix keypad scans on port pins, SPI drives LCD controllers or LED column drivers, and TWI reads capacitive-touch or real-time-clock peripherals. The 64KB Flash accommodates multi-language string tables and font bitmaps, which is often the flash bottleneck on smaller ATmega parts. Because the L-grade part runs from 2.7V, it can share a 3.3V rail with common LCD and RTC peripherals without level shifting - simplifying the board. Power-save sleep with keypad-interrupt wake keeps panel standby current low for always-on installations.
Recommended
Recommended Products Summary
Engineering reference data for ATMEGA64L-8AQ — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | ATMEGA64A-AUR | ATMEGA64L-8AI | ATMEGA64-16AU | ATMEGA640V-8AU |
|---|---|---|---|---|---|
| Package | 64-TQFP (14x14 mm) | 64-TQFP (14x14) - same | 64-TQFP (14x14) - same | 64-TQFP (14x14) - same | 64-TQFP (14x14) - same |
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Max Clock Frequency | 8 MHz | 16 MHz | 8 MHz | 16 MHz | 8 MHz |
| Flash Memory | 64 KB | 64 KB | 64 KB | 64 KB | 64 KB |
| SRAM | 4 KB | 4 KB | 4 KB | 4 KB | 8 KB |
| USART Count | 2 | 2 | 2 | 2 | 4 |
| Lifecycle Status | Mature / NRND (replaced by ATmega64A) | Active production | Mature / NRND | Mature / NRND | Active production |
| Operating Temperature | -40C to +85C | -40C to +85C | -40C to +85C | -40C to +85C | -40C to +85C |
Key Differentiators
- Low-voltage 8 MHz operation down to 2.7V (vs ATMEGA64-16AU)
- Active-production successor available pin-to-pin (vs ATMEGA64A-AUR)
- Simplest peripheral set of the 64-pin family (vs ATMEGA640V-8AU)
Design Notes
The ATMEGA64L-8AQ is an L-grade device specified from 2.7V to 5.5V at up to 8 MHz across the full industrial range. Unlike the 16 MHz ATmega64 variants, which need 4.5V minimum at top speed, this part meets 8 MHz at any voltage in range - useful for 3.3V designs sharing rails with LCDs and sensors. Decouple every VCC pin (pins 10, 33, 59) and AVCC with 0.1uF ceramics placed within 5 mm of each pin, and connect AGND (pin 23) to a quiet analog ground island for best ADC accuracy.
The 64-TQFP (14x14 mm) has 0.5 mm pitch leads; specify a footprint with slightly elongated pads for solder-joint inspection and route a solid ground plane under the device. If using the external memory interface (PA0-7 as AD bus, PC0-7 as A8-A15, PG0/PG1 as WR/RD with ALE on PG2/PG3), keep bus traces short and matched in length where possible, and add series termination of 22-33 ohm on high-speed ALE lines to suppress ringing. JTAG (PF4-PF7) should have a header on the board for production debugging even if unused in the final application.
This part is officially mature/not-recommended-for-new-designs and replaced by ATmega64A - starting a new design on ATMEGA64L-8AQ creates lifecycle risk. Second, the PEN pin (pin 1) must not be left floating if low-voltage serial programming is used; pull it per datasheet guidance. Third, the L suffix limits the clock to 8 MHz - firmware written for a 16 MHz ATmega64 will run at half speed if the fuse settings and F_CPU constant are not adjusted. Finally, verify EEPROM write endurance budgeting (100k cycles) in logging applications.
Compliance Information
RoHS-compliant per Microchip product data for the AQ suffix (RoHS-compliant packaging code). Additional REACH/halogen status not stated in provided data.
