ATMEGA64A-MU - 8-Bit AVR MCU, 16MHz, 64KB Flash | Microchip
MPN： ATMEGA64A-MU ✓ 啟用中ATMEGA64A-MU 概覽
An 8-bit AVR microcontroller is a Harvard-architecture RISC processor that executes most instructions in a single clock cycle, sitting at the low-power end of the power-management and embedded-control hierarchy. The ATmega family is widely used in industrial control, consumer appliances, and embedded systems where flash self-programmability and rich peripherals matter more than raw compute throughput.
Key features include 53 general-purpose I/O lines, 32 general-purpose working registers, four flexible timer/counters with compare modes, two USARTs, an 8-channel 10-bit ADC, a byte-oriented Two-Wire Interface (I2C-compatible), SPI, and a JTAG interface for on-chip debug and boundary scan. Read-while-write ISP Flash enables firmware updates in the field without halting code execution.
The AVR core combines a 131-instruction set with single-cycle execution, delivering up to 16 MIPS at 16 MHz. A real-time counter with separate oscillator supports RTC applications, while the enhanced power-save, ADC noise reduction, and standby idle modes let designers trade performance against microamp-level sleep currents. The ATmega64A is 100% pin compatible with the ATmega103 and can replace the ATmega103 on current printed circuit boards.
Typical applications include industrial automation controllers, HVAC and building-control nodes, battery-powered instrumentation, motor-control front ends, and embedded consumer devices requiring multiple communication interfaces.
Design consideration: at 16 MHz, keep decoupling capacitors close to the multiple VCC/GND pin pairs, and use the JTAG port for in-circuit debugging before disabling it as a general-purpose I/O.
This page synthesizes distributor pricing, drop-in alternatives, and practical design notes not found in the manufacturer datasheet.
直接替換替代品，適用於 ATMEGA64A-MU — 相同封裝，腳位對腳位相容。需重新設計 PCB 的不同封裝零件不列入。
此系列的變體
與下列產品可直接替換的同系列型號： ATMEGA64A-MU （相同外形與佔位） — 差異在於 Package, Debug Interface, Flash Memory, Timer/Counters, EEPROM.
ATMEGA64-16MI
✅ 直接替換 ⚠️ 規格未經驗證聯絡詢價
查看資料表 →ATMEGA128A-MUR
✅ 直接替換 ⚠️ 規格未經驗證聯絡詢價
查看資料表 →AT90CAN64-16MU
✅ 直接替換📋 參考替代品（不在目錄中）
ATMEGA649A-MU
✅ 直接替換聯絡詢價
查看資料表 →ATMEGA103-16MI
✅ 直接替換📋 參考替代品（不在目錄中）
ATMEGA64A-MU 最大額定值與電氣特性
| Core Architecture | 8-bit AVR RISC |
| Max Clock Frequency | 16 MHz |
| Flash Memory | 64 KB (32K x 16) ISP, read-while-write |
| EEPROM | 2 KB |
| SRAM | 4 KB |
| General Purpose I/O | 53 lines |
| Working Registers | 32 |
| Timer/Counters | 4 (two 8-bit, two 16-bit) plus RTC |
| USART Interfaces | 2 |
| ADC | 8-channel 10-bit |
| TWI (I2C) | Yes, byte-oriented |
| SPI | Yes |
| JTAG Interface | Yes (on-chip debug and boundary scan) |
| 封裝 | 64-QFN (9x9 mm), exposed pad, surface mount |
| 安裝類型 | Surface Mount |
| Pin Compatibility | 100% pin compatible with ATmega103 |
ATMEGA64A-MU 腳位配置
| 腳位 1 | PE0 — Port E bit 0 / RXD0 / PDI |
| 腳位 2 | PE1 — Port E bit 1 / TXD0 / PDO |
| 腳位 3 | PE2 — Port E bit 2 / XCK0 / AIN0 |
| 腳位 4 | PE3 — Port E bit 3 / AIN1 / OC3A |
| 腳位 5 | PE4 — Port E bit 4 / OC3B / INT4 |
| 腳位 6 | PE5 — Port E bit 5 / OC3C / INT5 |
| 腳位 7 | PE6 — Port E bit 6 / T3 / INT6 |
| 腳位 8 | PE7 — Port E bit 7 / ICP3 / INT7 / CLKO |
| 腳位 9 | GND — Ground |
| 腳位 10 | AVCC — Analog supply for ADC |
| 腳位 11 | PG0 — Port G bit 0 / WR (external memory write strobe) |
| 腳位 12 | PG1 — Port G bit 1 / RD (external memory read strobe) |
| 腳位 13 | PC0 — Port C bit 0 / A8 (external memory address) |
| 腳位 14 | PC1 — Port C bit 1 / A9 |
| 腳位 15 | PC2 — Port C bit 2 / A10 |
| 腳位 16 | PC3 — Port C bit 3 / A11 |
| 腳位 17 | PC4 — Port C bit 4 / A12 |
| 腳位 18 | PC5 — Port C bit 5 / A13 |
| 腳位 19 | PC6 — Port C bit 6 / A14 |
| 腳位 20 | PC7 — Port C bit 7 / A15 |
| 腳位 21 | GND — Ground |
| 腳位 22 | AREF — Analog reference for ADC |
| 腳位 23 | PF0 — Port F bit 0 / ADC0 |
| 腳位 24 | PF1 — Port F bit 1 / ADC1 |
| 腳位 25 | PF2 — Port F bit 2 / ADC2 |
| 腳位 26 | PF3 — Port F bit 3 / ADC3 |
| 腳位 27 | PF4 — Port F bit 4 / ADC4 / TCK (JTAG) |
| 腳位 28 | PF5 — Port F bit 5 / ADC5 / TMS (JTAG) |
| 腳位 29 | PF6 — Port F bit 6 / ADC6 / TDO (JTAG) |
| 腳位 30 | PF7 — Port F bit 7 / ADC7 / TDI (JTAG) |
| 腳位 31 | PA0 — Port A bit 0 / AD0 (external memory bus) / GPIO |
| 腳位 32 | PA1 — Port A bit 1 / AD1 |
| 腳位 33 | PA2 — Port A bit 2 / AD2 |
| 腳位 34 | PA3 — Port A bit 3 / AD3 |
| 腳位 35 | PA4 — Port A bit 4 / AD4 |
| 腳位 36 | PA5 — Port A bit 5 / AD5 |
| 腳位 37 | PA6 — Port A bit 6 / AD6 |
| 腳位 38 | PA7 — Port A bit 7 / AD7 |
| 腳位 39 | PB0 — Port B bit 0 / SS (SPI slave select) / OC0 |
| 腳位 40 | PB1 — Port B bit 1 / SCK (SPI clock) |
| 腳位 41 | PB2 — Port B bit 2 / MOSI (SPI master out) |
| 腳位 42 | PB3 — Port B bit 3 / MISO (SPI master in) |
| 腳位 43 | PB4 — Port B bit 4 / OC2 (Timer2 output compare) |
| 腳位 44 | PB5 — Port B bit 5 / OC1A (Timer1 output compare A) |
| 腳位 45 | PB6 — Port B bit 6 / OC1B (Timer1 output compare B) |
| 腳位 46 | PB7 — Port B bit 7 / OC0A / OC1C |
| 腳位 47 | VCC — Digital supply voltage |
| 腳位 48 | GND — Ground |
| 腳位 49 | PD0 — Port D bit 0 / SCL (TWI clock) / INT0 |
| 腳位 50 | PD1 — Port D bit 1 / SDA (TWI data) / INT1 |
| 腳位 51 | PD2 — Port D bit 2 / TXD1 (USART1) / INT2 |
| 腳位 52 | PD3 — Port D bit 3 / RXD1 (USART1) / INT3 |
| 腳位 53 | PD4 — Port D bit 4 / ICP1 (Timer1 input capture) |
| 腳位 54 | PD5 — Port D bit 5 / XCK1 (USART1 clock) |
| 腳位 55 | PD6 — Port D bit 6 / T1 (Timer1 external clock) |
| 腳位 56 | PD7 — Port D bit 7 / T2 (Timer2 external clock) |
| 腳位 57 | PG2 — Port G bit 2 / ALE (external memory address latch enable) |
| 腳位 58 | PG3 — Port G bit 3 / TOSC2 (RTC oscillator output) |
| 腳位 59 | PG4 — Port G bit 4 / TOSC1 (RTC oscillator input) |
| 腳位 60 | RESET — Reset input (active low) |
| 腳位 61 | VCC — Digital supply voltage |
| 腳位 62 | GND — Ground |
| 腳位 63 | XTAL2 — Main crystal oscillator output |
| 腳位 64 | XTAL1 — Main crystal oscillator input / external clock |
典型應用
ATMEGA64A-MU 適用於 6 應用s: Industrial Automation Controllers, HVAC and Building Control Nodes, Battery-Powered Instrumentation, Motor Control Front Ends, Embedded Consumer Devices, Legacy ATmega103 Board Redesign Avoidance.
Industrial Automation Controllers
The ATMEGA64A-MU fits industrial controller boards because its 64KB ISP Flash accommodates protocol stacks and state machines, its two USARTs drive RS-485 and a debug console simultaneously, and 53 GPIO lines interface relays, optocouplers, and limit switches directly. The 16 MHz single-cycle AVR core delivers deterministic interrupt latency for control loops up to the kilohertz range. Placed as the main MCU with a 5V rail and 100nF decoupling at each VCC pin, it reads encoders via timer capture and communicates over TWI or SPI to remote I/O expanders. Its JTAG port enables in-field debugging of deployed machinery controllers.
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HVAC and Building Control Nodes
Building automation nodes benefit from the ATmega64A's real-time counter with the separate 32.768 kHz TOSC oscillator, enabling battery-backed timekeeping across power loss, while the 8-channel 10-bit ADC samples temperature, humidity, and pressure sensor chains. The 4KB SRAM holds multiple networked sensor buffers, and the two USARTs allow simultaneous RS-485 bus and service-port connectivity. Operating in power-save mode between acquisition cycles keeps standby current at microamp levels per the datasheet power tables, extending battery life in wireless-free, wall-thermostat-style deployments. The exposed-pad QFN improves heat dissipation in sealed enclosures.
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Battery-Powered Instrumentation
Portable instruments leverage the ATMEGA64A-MU's power-down and power-save modes to stretch battery life while retaining the real-time counter for timestamping. The 10-bit ADC with internal reference digitizes bridge and thermistor inputs, and ADC noise reduction mode suppresses core clock noise during conversions, improving effective resolution at low sample rates. The 64KB Flash stores calibration tables and logging firmware, while 4KB SRAM buffers measurement records between UART or SPI uploads. With a 3V coin-cell or Li-ion rail through an LDO, the QFN's small 9x9 mm footprint suits handheld and panel-meter form factors.
推薦
Motor Control Front Ends
The ATmega64A's four timer/counters include two 16-bit units with input capture and three PWM compare channels per port B and E grouping, generating complementary or phase-correct PWM for DC and stepper motor drives. Input capture pins (ICP1, ICP3) timestamp quadrature or Hall sensor edges with 62.5 ns resolution at 16 MHz, enabling closed-loop speed control without external logic. The 10-bit ADC reads current-sense shunt amplifiers, and the fast AVR interrupt system handles overcurrent faults. External memory bus pins (ports A and C with ALE, WR, RD) allow expansion for larger trajectory tables via SRAM in servo applications.
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Embedded Consumer Devices
Consumer appliances such as coffee machines, thermostats, and small printers use the ATMEGA64A-MU for its balance of Flash capacity and peripheral richness at a mainstream price. The byte-oriented TWI (I2C) manages touch controllers and EEPROM accessories, SPI drives display drivers and flash storage, and the dual USART supports factory test ports. Read-while-write ISP Flash allows field firmware updates through a bootloader without pausing output-critical timers. The 64-QFN with exposed pad solders reliably on standard reflow lines, and its 16 MHz core delivers responsive UI scan rates for keypads and rotary encoders in 5V or 3.3V designs.
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Legacy ATmega103 Board Redesign Avoidance
Because Microchip documents the ATmega64A as 100% pin compatible with the ATmega103, the ATMEGA64A-MU is the standard migration path for boards designed around the obsolete ATmega103 in the 64-MLF/QFN footprint. The datasheet application note 'Replacing ATmega103 by ATmega64A' details register and peripheral differences. Designers gain doubled Flash (64KB), a second USART, more timers, and modern JTAG debugging without a PCB respin. This application is common in long-lifecycle industrial and medical equipment where recertification of a new board would be costly, making the drop-in swap the lowest-risk modernization route.
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推薦產品摘要
工程參考資料，適用於 ATMEGA64A-MU — 比較、設計指引及合規資訊。
選型指南
與替代品比較
| 參數 | 本產品 | ATMEGA64-16MI | ATMEGA128A-MU | AT90CAN64-16MU | ATMEGA649A-MU |
|---|---|---|---|---|---|
| Package | 64-QFN (9x9 mm) | 64-QFN (9x9 mm) - same | 64-QFN (9x9 mm) - same | 64-QFN EP - same | 64-QFN - same |
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Flash Memory | 64 KB | 64 KB | 128 KB | 64 KB | 64 KB |
| Hardware CAN Controller | No | No | No | Yes (CAN 2.0A/B) | No |
| Segment LCD Controller | No | No | No | No | Yes |
| Core Compatibility | 100% pin compatible with ATmega103 | Same die family (pre-A revision) | Pin-compatible family lineage | AT90 CAN AVR family | ATmega649 family (LCD pin remap) |
主要差異化特點
- Doubling of program memory in the same footprint (對比ATMEGA128A-MU)
- Integrated hardware CAN controller (對比AT90CAN64-16MU)
- Direct ATmega103 legacy replacement (對比ATMEGA103-16MI)
設計說明
The 64-QFN package exposes a large thermal pad on the underside that is internally connected to ground. Solder it to a ground copper pour with an array of thermal vias (typically 4x4 grid) to improve both heat dissipation and signal-ground integrity. Place 100nF ceramic decoupling capacitors within 2 mm of each VCC pin pair, plus one 4.7uF-10uF bulk capacitor near the supply entry. Connect AVCC to VCC through an LC filter (10uH ferrite bead plus 100nF) when ADC accuracy matters, and route AREF with its own decoupling capacitor.
JTAG is enabled by default from the factory on PORTF pins 4-7, disabling those ADC channels and GPIO. If your design uses ADC4-ADC7 or those port pins, disable JTAG via the JTD bit in MCUCSR (written twice within four cycles) or clear the JTAGEN fuse. Also note that RESET shares functions with PC6 in some AVR members - on ATmega64A RESET is a dedicated pin, but verify fuse settings (RSTDISBL must remain unprogrammed) before production programming, since programming it can permanently disable ISP entry.
For external memory bus operation (ALE, WR, RD with ports A and C), keep bus traces short and matched where possible, and latch AD0-AD7 with a 74x573 triggered by ALE. When running a 16 MHz crystal, place it within 5 mm of XTAL1/XTAL2 with grounded guard traces and use a crystal load capacitance per the crystal manufacturer's specification. The RTC TOSC 32.768 kHz circuit on PG3/PG4 is noise sensitive - isolate it from switching regulators and high-current PWM traces to avoid missed real-time ticks.
合規資訊
Current-production Microchip part supplied in standard RoHS-compliant, lead-free packaging per distributor listings. REACH and halogen-free declarations should be confirmed on the Microchip product compliance page for the exact ordering code.
