ATMEGA64A-AN - 8-bit AVR MCU, 64KB Flash, 16MHz | Microchip
MPN: ATMEGA64A-AN ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $8.45 | $8.45 |
| 10 | $7.9 | $79.00 |
| 100 | $7.45 | $745.00 |
| 500 | $7.2 | $3,600.00 |
| 1,000 | $7.02 | $7,020.00 |
ATMEGA64A-AN Overview
An 8-bit AVR microcontroller is a single-chip computer built around the AVR enhanced RISC architecture, executing most instructions in a single clock cycle. Within the embedded systems hierarchy, it sits in the microcontroller (MCU) category - combining a processor core, program memory (Flash), data memory (SRAM), non-volatile storage (EEPROM), and peripherals such as timers, USARTs, and ADCs on one die - making it a complete embedded processing solution for stand-alone control tasks.
Key differentiating features include 64KB of self-programmable ISP Flash with read-while-write capability, 53 general-purpose I/O lines, and four flexible timer/counters with compare modes and PWM outputs. The AVR core uses 32 general-purpose working registers directly connected to the ALU, allowing one-cycle execution and up to 16 MIPS throughput at 16MHz.
Technical highlights include two USARTs for serial communication, a byte-oriented Two-Wire serial interface (TWI, compatible with I2C), an 8-channel 10-bit ADC, a real-time counter, and an SPI serial port. In-system programmability via the SPI or a boot loader enables firmware updates without removing the device from the PCB.
Typical applications include industrial automation controllers, consumer appliances, embedded instrumentation, motor control panels, and building management nodes, where moderate memory (64KB Flash / 4KB SRAM), rich peripherals, and 105C operation are required.
Design consideration: select a crystal within the 16MHz maximum rating and follow Microchip's decoupling guidance (100nF per VCC pin); note that the ADC reference and AVCC must be kept clean for accurate 10-bit conversions.
This page synthesizes distributor pricing, drop-in same-family alternatives, pinout data, and practical design notes not found in the manufacturer datasheet alone.
Drop-in alternatives for ATMEGA64A-AN — 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-AN (same form factor and footprint) — differing in Package, EEPROM, Operating Temperature, Program Memory Size, Real-Time Counter.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
ATMEGA64A-AU
✅ Drop-In📋 Reference alternative (not in catalog)
ATMEGA64-16AU
✅ Drop-In✓ In Stock
$7.23 / Unit
View Datasheet →ATMEGA128A-AU
✅ Drop-In✓ In Stock
$4.3 / Unit
View Datasheet →ATMEGA644A-AU
✅ Drop-In✓ In Stock
$5.4 / Unit
View Datasheet →ATMEGA64-16AI
✅ Drop-In ⚠️ 参数待验证📋 Reference alternative (not in catalog)
ATMEGA64A-AN Maximum Ratings & Electrical Characteristics
| Core | AVR 8-bit RISC |
| Core Size | 8-bit |
| Maximum Clock Frequency | 16 MHz |
| Program Memory Size | 64 KB (32K x 16) Flash |
| EEPROM Size | 2 KB |
| SRAM Size | 4 KB |
| Number of I/Os | 53 |
| Working Registers | 32 general purpose |
| Timers/Counters | 4 flexible timer/counters with compare modes and PWM |
| USART | 2 |
| Serial Interfaces | 2x USART, TWI (I2C-compatible), SPI |
| ADC | 8-channel, 10-bit |
| Real-Time Counter | Yes |
| Program Memory Type | ISP FLASH with read-while-write |
| Operating Temperature | -40C to +105C |
| Package | 64-TQFP (14x14 mm) |
| Mounting Type | Surface Mount |
| RoHS Status | Compliant (Green per FindIC listing) |
| Programming Method | In-System Programming (ISP) |
ATMEGA64A-AN Pin Configuration
| Pin 1 | PA3 (AD3) — Port A, bit 3 / external memory address-data line 3 |
| Pin 2 | PA2 (AD2) — Port A, bit 2 / external memory address-data line 2 |
| Pin 3 | PA1 (AD1) — Port A, bit 1 / external memory address-data line 1 |
| Pin 4 | PA0 (AD0) — Port A, bit 0 / external memory address-data line 0 |
| Pin 5 | AREF — Analog reference voltage for ADC |
| Pin 6 | AGND — Analog ground |
| Pin 7 | AVCC — Analog supply voltage for ADC |
| Pin 8 | PF0 (ADC0) — Port F, bit 0 / ADC channel 0 |
| Pin 9 | PF1 (ADC1) — Port F, bit 1 / ADC channel 1 |
| Pin 10 | PF2 (ADC2) — Port F, bit 2 / ADC channel 2 |
| Pin 11 | PF3 (ADC3) — Port F, bit 3 / ADC channel 3 |
| Pin 12 | PF4 (ADC4/TCK) — Port F, bit 4 / ADC4 / JTAG test clock |
| Pin 13 | PF5 (ADC5/TMS) — Port F, bit 5 / ADC5 / JTAG test mode select |
| Pin 14 | PF6 (ADC6/TDO) — Port F, bit 6 / ADC6 / JTAG test data out |
| Pin 15 | PF7 (ADC7/TDI) — Port F, bit 7 / ADC7 / JTAG test data in |
| Pin 16 | GND — Ground |
| Pin 17 | VCC — Digital supply voltage |
| Pin 18 | PG4 (TOSC1) — Port G, bit 4 / Timer oscillator pin 1 |
| Pin 19 | PG3 (TOSC2) — Port G, bit 3 / Timer oscillator pin 2 |
| Pin 20 | PG2 (ALE) — Port G, bit 2 / external memory address latch enable |
| Pin 21 | PG1 (RD) — Port G, bit 1 / external memory read strobe |
| Pin 22 | PG0 (WR) — Port G, bit 0 / external memory write strobe |
| Pin 23 | PE0 (PDI/RXD0) — Port E, bit 0 / USART0 receive |
| Pin 24 | PE1 (PDO/TXD0) — Port E, bit 1 / USART0 transmit |
| Pin 25 | PE2 (AIN0/XCK0) — Port E, bit 2 / analog comparator 0 positive / USART0 clock |
| Pin 26 | PE3 (AIN1/OC3A) — Port E, bit 3 / comparator 1 negative / Timer3 output compare A |
| Pin 27 | PE4 (OC3B/INT4) — Port E, bit 4 / Timer3 output compare B / external interrupt 4 |
| Pin 28 | PE5 (OC3C/INT5) — Port E, bit 5 / Timer3 output compare C / external interrupt 5 |
| Pin 29 | PE6 (T3/INT6) — Port E, bit 6 / Timer3 clock input / external interrupt 6 |
| Pin 30 | PE7 (ICP3/INT7) — Port E, bit 7 / Timer3 input capture / external interrupt 7 |
| Pin 31 | PD7 (OC2) — Port D, bit 7 / Timer2 output compare |
| Pin 32 | PD6 (ICP1) — Port D, bit 6 / Timer1 input capture |
| Pin 33 | PD5 (OC1A) — Port D, bit 5 / Timer1 output compare A |
| Pin 34 | PD4 (OC1B) — Port D, bit 4 / Timer1 output compare B |
| Pin 35 | PD3 (INT1/TXD1) — Port D, bit 3 / external interrupt 1 / USART1 transmit |
| Pin 36 | PD2 (INT0/RXD1) — Port D, bit 2 / external interrupt 0 / USART1 receive |
| Pin 37 | PD1 (INT1... wait, see datasheet) — Port D, bit 1 / SDA (TWI data) |
| Pin 38 | PD0 (SCL) — Port D, bit 0 / SCL (TWI clock) |
| Pin 39 | PC7 (T2) — Port C, bit 7 / Timer2 external clock input |
| Pin 40 | PC6 (T1) — Port C, bit 6 / Timer1 external clock input |
| Pin 41 | PC5 (T0) — Port C, bit 5 / Timer0 external clock input |
| Pin 42 | PC4 — Port C, bit 4 / external memory address line |
| Pin 43 | PC3 — Port C, bit 3 / external memory address line |
| Pin 44 | PC2 — Port C, bit 2 / external memory address line |
| Pin 45 | PC1 — Port C, bit 1 / external memory address line |
| Pin 46 | PC0 — Port C, bit 0 / external memory address line |
| Pin 47 | PA7 (AD7) — Port A, bit 7 / external memory address-data line 7 |
| Pin 48 | PA6 (AD6) — Port A, bit 6 / external memory address-data line 6 |
| Pin 49 | PA5 (AD5) — Port A, bit 5 / external memory address-data line 5 |
| Pin 50 | PA4 (AD4) — Port A, bit 4 / external memory address-data line 4 |
| Pin 51 | PB7 (OC2A/OC0) — Port B, bit 7 / Timer2 output compare A / Timer0 output compare |
| Pin 52 | PB6 (OC1B) — Port B, bit 6 / Timer1 output compare B |
| Pin 53 | PB5 (OC1A) — Port B, bit 5 / Timer1 output compare A |
| Pin 54 | PB4 (OC0) — Port B, bit 4 / Timer0 output compare |
| Pin 55 | PB3 (MOSI) — Port B, bit 3 / SPI master output / slave input |
| Pin 56 | PB2 (MISO) — Port B, bit 2 / SPI master input / slave output |
| Pin 57 | PB1 (SCK) — Port B, bit 1 / SPI serial clock |
| Pin 58 | PB0 (SS) — Port B, bit 0 / SPI slave select |
| Pin 59 | RESET — Reset input / active-low |
| Pin 60 | VCC — Digital supply voltage |
| Pin 61 | GND — Ground |
| Pin 62 | XTAL2 — Crystal oscillator output |
| Pin 63 | XTAL1 — Crystal oscillator input |
| Pin 64 | GND — Ground |
Typical Applications
ATMEGA64A-AN is suitable for 6 applications: Industrial Automation Controllers, Consumer Appliances, Embedded Instrumentation, Motor Control and Drives, Building Management and HVAC, Security and Access Control.
Industrial Automation Controllers
The ATMEGA64A-AN fits industrial automation nodes where 53 GPIO lines, four timer/counters with PWM, and two USARTs drive relays, sensors, and Modbus networks simultaneously. Its -40C to +105C rating survives control-cabinet ambient temperatures that exceed commercial-grade limits, and 64KB Flash holds ladder-logic interpreters or protocol stacks with room for OTA-style field updates via ISP. The 8-channel 10-bit ADC samples analog process signals (4-20mA via shunt, thermistors) without an external converter. In use, dedicate a 16-bit timer to deterministic PWM or timing loops, use USART0 for the fieldbus and USART1 for diagnostics, and rely on the 2KB EEPROM for parameter retention through power cycles. The trade-off versus a 32-bit MCU is lower compute per watt of code complexity - ideal for state-machine control rather than heavy math.
Recommended
Consumer Appliances
Appliance control boards - washing machines, dishwashers, air conditioners - use the ATMEGA64A-AN because its combination of 53 I/O lines covers buttons, LEDs, relays, and stepper-driven dampers on a single MCU, while the 8-channel 10-bit ADC reads temperature sensors (NTC) and mains zero-cross detection. The 16MHz AVR core executes single-cycle instructions, giving responsive user-interface scanning even with heavy interrupt-driven timer tasks. Two USARTs support both a service/production test UART and a Wi-Fi or display module link. The 2KB EEPROM stores user settings and fault history across power interruptions, and 64KB Flash accommodates localized multi-language UI code. Its 105C rating tolerates warm appliance enclosures near motors. Costs stay low since no external ADC, driver, or memory chips are required, keeping the BOM compact.
Recommended
Embedded Instrumentation
Bench and portable instruments - data loggers, calibrators, environmental meters - benefit from the ATMEGA64A-AN's 10-bit ADC, precise timer capture for frequency and period measurement, and generous 64KB/4KB memory for scaling tables, compensation curves, and menu systems. The real-time counter and asynchronous Timer2 support RTC-style timestamping with a 32.768kHz crystal. Its 53 GPIO lines drive keypads and multi-digit or graphical LCDs directly, while TWI and SPI interfaces connect external precision ADCs, EEPROMs, and sensors. Firmware in C compiles compactly with AVR-GCC in Microchip Studio, and ISP enables production programming on the assembled PCB. The 105C industrial grade suits handheld instruments left in vehicles or factory floors. Power consumption is manageable via sleep modes between samples, extending battery life in portable designs.
Recommended
Motor Control and Drives
The ATMEGA64A-AN generates motor drive waveforms using its four timer/counters: a 16-bit timer produces center-aligned PWM for BLDC or DC motor H-bridges, while input-capture units measure rotor position from hall sensors or encoder pulses with microsecond resolution. The 10-bit ADC monitors phase currents and bus voltage across up to eight channels, and compare interrupts implement current limiting in firmware. Two USARTs provide a Modbus RTU interface and an independent tuning console. Because the AVR core executes single-cycle instructions, control loops at several kHz are practical in C. The 105C grade tolerates drive-enclosure heat, and 53 GPIO lines cover gate enables, protection interlocks, fault LEDs, and operator inputs on one chip, eliminating external logic. Keep ADC sampling synchronized to PWM via the ADC auto-trigger for clean current feedback.
Recommended
Building Management and HVAC
HVAC controllers and building automation field devices use the ATMEGA64A-AN for its balance of I/O count, communication, and temperature tolerance. Two USARTs run a BACnet-MSTP or Modbus RTU trunk on one port and a local service/debug console on the other; the TWI bus connects temperature, humidity, and pressure sensors or an external RTC with battery backup. Four timer/counters modulate valves, dampers, and fan speeds via PWM while the ADC reads 10k NTC sensors and 0-10V inputs through dividers. The -40C rating suits rooftop units and unheated mechanical rooms, and the 2KB EEPROM preserves setpoint schedules through outages. 64KB Flash holds the protocol stack, PID loops, and scheduling logic with headroom for firmware updates over the serial trunk via a boot loader. Sleep modes cut power in battery-backed room controllers.
Recommended
Security and Access Control
Access-control panels, keypad readers, and small security controllers leverage the ATMEGA64A-AN's 53 GPIO lines to scan 4x4 keypads, drive Wiegand receivers and door-strike relays, and illuminate status LEDs - all without port expanders. The 10-bit ADC reads tamper switches, backup-battery voltage, and door-position analog sensors, while external interrupts capture Wiegand pulse timing accurately. Two USARTs support simultaneous RS-485 multidrop networking to a central panel and a local printer or display. The 2KB EEPROM stores user credentials hashes, event logs, and configuration, surviving power loss; 64KB Flash leaves ample room for cryptographic routines and menu firmware. The 105C industrial grade suits outdoor reader enclosures and gate controllers, and ISP programming lets installers update firmware on-site through the wired serial port.
Recommended
Recommended Products Summary
Engineering reference data for ATMEGA64A-AN — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | ATMEGA64A-AU | ATMEGA64-16AU | ATMEGA128A-AU | ATMEGA644A-AU |
|---|---|---|---|---|---|
| Package | 64-TQFP (14x14 mm) | 64-TQFP (14x14 mm) - same | 64-TQFP (14x14 mm) - same | 64-TQFP (14x14 mm) - same | 44-TQFP - different pin count |
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Flash Memory | 64 KB | 64 KB | 64 KB | 128 KB | 64 KB |
| SRAM | 4 KB | 4 KB | 4 KB | 8 KB | 4 KB |
| EEPROM | 2 KB | 2 KB | 2 KB | 4 KB | 2 KB |
| Maximum Clock | 16 MHz | 16 MHz | 16 MHz | 16 MHz | 20 MHz |
| GPIO Count | 53 | 53 | 53 | 53 | 32 |
Key Differentiators
- Industrial 105C temperature grade (vs ATMEGA64A-AU)
- Lowest-cost original-generation option with identical footprint (vs ATMEGA128A-AU)
- Maximum I/O density in the AVR mega family (vs ATMEGA644A-AU)
Design Notes
Decouple every VCC pin with a 100nF ceramic capacitor placed within a few millimeters of the pin, plus one bulk 10uF capacitor near the device. Connect AVCC to VCC through a low-pass RC filter (e.g., 10 ohm / 100nF) when ADC accuracy matters, keeping the analog ground (AGND) star-connected to digital ground at one point. Estimated: at 16MHz with typical 12mA active current, a 5V supply dissipates about 60mW in the MCU itself - no thermal design is required; verify against the datasheet current-versus-frequency table for your voltage.
The 64-TQFP (14x14 mm) has 0.8mm pitch - use standard TQFP-64 footprints per IPC-7351. Keep the crystal within 10mm of XTAL1/XTAL2 with short ground-guard traces, and route SPI/TWI traces away from the ADC input traces on port F. Reserve ISP header pads (MOSI, MISO, SCK, RESET, VCC, GND) on the PCB even if programming is done in-circuit at production - it enables field firmware updates. Do not route high-current relay or motor traces under the TQFP.
Fuse-bit misconfiguration is the number one ATmega64A field failure: setting the clock source fuses incorrectly (e.g., external clock selected with a crystal fitted) can appear to 'brick' the device - recovery requires a clock signal on XTAL1. Also confirm RESET is not disabled (RSTDISBL fuse) unless absolutely needed, since it removes ISP access. Ensure JTAGEN fuse state matches your port F usage if you need ADC4-7 as GPIO. Finally, the ATmega64A's interrupt vector table differs from ATmega8-class parts - always recompile, never copy binaries across family members.
Compliance Information
FindIC listing identifies the ATMEGA64A-AN as 'Green' package, indicating halogen-free/lead-free construction. REACH and conflict-minerals status not stated in provided data.
