ATMEGA64-16AJ - 8-Bit AVR MCU 16MHz 64KB Flash | Microchip
MPN: ATMEGA64-16AJ ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $9.2 | $9.20 |
| 10 | $8.35 | $83.50 |
| 100 | $7.6 | $760.00 |
| 500 | $6.95 | $3,475.00 |
| 1,000 | $6.4 | $6,400.00 |
ATMEGA64-16AJ Overview
An AVR ATmega microcontroller is a member of the AVR enhanced-RISC 8-bit MCU family, sitting within the broader hierarchy of microcontrollers under the microprocessor and embedded processor category. By executing most of its powerful instructions in a single clock cycle, AVR cores achieve throughput approaching one MIPS per MHz, letting system designers optimize power consumption versus processing speed.
Key features include the advanced RISC architecture with 130 instructions (most single-cycle executed) and 32 x 8 general purpose working registers, 64KB of self-programming In-System Programmable Flash organized as 32K x 16, and a rich peripheral set: two 8-bit and one 16-bit timer/counters, two USARTs, SPI interface, two-wire serial (I2C-compatible) interface, and an analog comparator. The JTAG boundary-scan capability supports IEEE 1149.1-style test access and on-chip debugging, easing board-level manufacturing test.
The self-programming Flash allows the bootloader to update firmware in the field, while 2KB EEPROM preserves calibration and configuration data through power cycles. The 8-channel 10-bit ADC with internal reference supports sensor front-ends directly on-chip, reducing bill-of-materials complexity.
Typical applications include industrial automation controllers, embedded control systems requiring external memory interfaces (via the parallel port A-D on-chip bus), instrumentation and data loggers, and legacy board redesigns where the ATmega64 pinout is already qualified.
Design consideration: the 16 MHz speed grade requires a 4.5V to 5.5V supply; below that, the clock must be derated according to the datasheet frequency-versus-voltage curve.
This page synthesizes distributor pricing, pin-compatible drop-in alternatives (including the ATmega128 on the same footprint), and practical design notes not found in the manufacturer datasheet.
Drop-in alternatives for ATMEGA64-16AJ — 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 ATMEGA64-16AJ (same form factor and footprint) — differing in Package, ADC, RoHS Status, EEPROM, Maximum CPU Speed.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
ATMEGA64-16AU
✅ Drop-In✓ In Stock
$7.23 / Unit
View Datasheet →ATMEGA64A-AU
✅ Drop-In ⚠️ 参数待验证📋 Reference alternative (not in catalog)
ATMEGA64A-AUR
✅ Drop-In ⚠️ 参数待验证✓ In Stock
$4.1 / Unit
View Datasheet →ATMEGA64L-16AU
✅ Drop-In ⚠️ 参数待验证📋 Reference alternative (not in catalog)
ATMEGA128-16AU
✅ Drop-In ⚠️ 参数待验证✓ In Stock
$14.3 / Unit
View Datasheet →ATMEGA64-16AJ Maximum Ratings & Electrical Characteristics
| Core Processor | AVR |
| Core Size | 8-Bit |
| Speed | 16 MHz |
| Flash Program Memory | 64 KB (32K x 16) |
| SRAM | 4 KB |
| EEPROM | 2 KB |
| Operating Supply Voltage | 4.5 V to 5.5 V (5V) |
| ADC Channels | 8 channels, 10-bit |
| Peripherals | POR, PWM, WDT |
| Connectivity | I2C, SPI, UART/USART, JTAG |
| Number of I/O | 53 |
| MIPS Throughput | 16 MIPS at 16 MHz |
| RISC Instruction Set | 130 instructions, most single-cycle |
| Package | 64-TQFP (14x14 mm) |
| Mounting Type | Surface Mount |
| Oscillator Type | Internal + External (crystal/resonator) |
ATMEGA64-16AJ Pin Configuration
| Pin 1 | PEN — Programming enable (serial programming data entry) |
| Pin 2 | PE0/RXD0 — USART0 receive / digital I/O port E bit 0 |
| Pin 3 | PE1/TXD0 — USART0 transmit / digital I/O port E bit 1 |
| Pin 4 | PE2/XCK0/AIN0 — USART0 external clock / analog comparator input 0 |
| Pin 5 | PE3/OC3A/AIN1 — Timer3 output compare A / analog comparator input 1 |
| Pin 6 | PE4/OC3B/INT4 — Timer3 output compare B / external interrupt 4 |
| Pin 7 | PE5/OC3C/INT5 — Timer3 output compare C / external interrupt 5 |
| Pin 8 | PE6/T3/INT6 — Timer3 clock input / external interrupt 6 |
| Pin 9 | PE7/ICP3/INT7 — Timer3 input capture / external interrupt 7 |
| Pin 10 | PB0/SS — SPI slave select / digital I/O port B bit 0 |
| Pin 11 | PB1/SCK — SPI clock / digital I/O port B bit 1 |
| Pin 12 | PB2/MOSI — SPI master out / digital I/O port B bit 2 |
| Pin 13 | PB3/MISO — SPI master in / digital I/O port B bit 3 |
| Pin 14 | PB4/OC0 — Timer0 output compare / digital I/O port B bit 4 |
| Pin 15 | PB5/OC1A — Timer1 output compare A / digital I/O port B bit 5 |
| Pin 16 | PB6/OC1B — Timer1 output compare B / digital I/O port B bit 6 |
| Pin 17 | PB7/OC2/OC1C — Timer2 or Timer1 output compare C / port B bit 7 |
| Pin 18 | VCC — Digital supply voltage |
| Pin 19 | GND — Ground |
| Pin 20 | PG0/WR — External memory write strobe / port G bit 0 |
| Pin 21 | PG1/RD — External memory read strobe / port G bit 1 |
| Pin 22 | PC0/A8 — External memory address bit 8 / port C bit 0 |
| Pin 23 | PC1/A9 — External memory address bit 9 / port C bit 1 |
| Pin 24 | PC2/A10 — External memory address bit 10 / port C bit 2 |
| Pin 25 | PC3/A11 — External memory address bit 11 / port C bit 3 |
| Pin 26 | PC4/A12 — External memory address bit 12 / port C bit 4 |
| Pin 27 | PC5/A13 — External memory address bit 13 / port C bit 5 |
| Pin 28 | PC6/A14 — External memory address bit 14 / port C bit 6 |
| Pin 29 | PC7/A15 — External memory address bit 15 / port C bit 7 |
| Pin 30 | GND — Ground |
| Pin 31 | AREF — ADC analog reference voltage |
| Pin 32 | PA7/ADC7 — ADC channel 7 / external memory data bit 7 |
| Pin 33 | PA6/ADC6 — ADC channel 6 / external memory data bit 6 |
| Pin 34 | PA5/ADC5 — ADC channel 5 / external memory data bit 5 |
| Pin 35 | PA4/ADC4 — ADC channel 4 / external memory data bit 4 |
| Pin 36 | PA3/ADC3 — ADC channel 3 / external memory data bit 3 |
| Pin 37 | PA2/ADC2 — ADC channel 2 / external memory data bit 2 |
| Pin 38 | PA1/ADC1 — ADC channel 1 / external memory data bit 1 |
| Pin 39 | PA0/ADC0 — ADC channel 0 / external memory data bit 0 |
| Pin 40 | VCC — Digital supply voltage |
| Pin 41 | PF0/ADC0 — ADC channel 0 / digital I/O port F bit 0 |
| Pin 42 | PF1/ADC1 — ADC channel 1 / digital I/O port F bit 1 |
| Pin 43 | PF2/ADC2 — ADC channel 2 / digital I/O port F bit 2 |
| Pin 44 | PF3/ADC3 — ADC channel 3 / digital I/O port F bit 3 |
| Pin 45 | PF4/ADC4/TCK — ADC channel 4 / JTAG test clock |
| Pin 46 | PF5/ADC5/TMS — ADC channel 5 / JTAG test mode select |
| Pin 47 | PF6/ADC6/TDO — ADC channel 6 / JTAG test data out |
| Pin 48 | PF7/ADC7/TDI — ADC channel 7 / JTAG test data in |
| Pin 49 | GND — Ground |
| Pin 50 | VCC — Digital supply voltage |
| Pin 51 | PD0/SCL/INT0 — I2C clock / external interrupt 0 / port D bit 0 |
| Pin 52 | PD1/SDA/INT1 — I2C data / external interrupt 1 / port D bit 1 |
| Pin 53 | PD2/RXD1/INT2 — USART1 receive / external interrupt 2 / port D bit 2 |
| Pin 54 | PD3/TXD1/INT3 — USART1 transmit / external interrupt 3 / port D bit 3 |
| Pin 55 | PD4/ICP1 — Timer1 input capture / port D bit 4 |
| Pin 56 | PD5/XCK1 — USART1 external clock / port D bit 5 |
| Pin 57 | PD6/T1 — Timer1 external clock input / port D bit 6 |
| Pin 58 | PD7/T0 — Timer0 external clock input / port D bit 7 |
| Pin 59 | VCC — Digital supply voltage |
| Pin 60 | GND — Ground |
| Pin 61 | PG2/ALE — External memory address latch enable / port G bit 2 |
| Pin 62 | PG3/TOSC2 — Timer oscillator output / port G bit 3 |
| Pin 63 | PG4/TOSC1 — Timer oscillator input / port G bit 4 |
| Pin 64 | RESET — Reset input (active low) |
Typical Applications
ATMEGA64-16AJ is suitable for 6 applications: Industrial Automation Controllers, Embedded Data Loggers, Instrumentation and Test Equipment, Motor Control Systems, Communication and Protocol Converters, Legacy Board Redesigns and BOM Continuity.
Industrial Automation Controllers
The ATMEGA64-16AJ fits industrial automation controllers because its 5V supply provides robust noise margins, the industrial temperature grade suits factory-floor conditions, and the external memory interface (ports A-C with ALE, WR, RD) allows memory-mapped I/O expansion for relays, counters, and displays. The 8-channel 10-bit ADC directly samples analog sensor inputs at up to 10-bit resolution without an external converter, and the watchdog timer with brown-out detection supports fault recovery in continuous-duty equipment. With 16 MIPS of throughput at 16 MHz, the AVR core handles state machines, MODBUS-style UART polling across two USARTs, and PID loops concurrently. Designers typically clock the part from a 16 MHz crystal and use the SPI port for configuration peripherals, keeping the 64KB Flash ample for protocol stacks and HMI firmware.
Recommended
Embedded Data Loggers
Data-logging systems benefit from the ATMEGA64-16AJ's combination of 64KB self-programming Flash and 2KB EEPROM: the EEPROM stores calibration constants and power-fail-safe state, while the Flash supports field firmware updates via a bootloader over either USART. The 8-channel 10-bit ADC digitizes up to eight sensor channels, and the 4KB SRAM buffers timestamped samples between transfers over SPI to external storage or over a USART to a modem. The 16 MHz clock gives headroom for real-time stamping and CRC computation in firmware. Because the part runs from a single 5V rail with low-power sleep modes, battery-backed loggers can duty-cycle the MCU between acquisition windows. JTAG debugging simplifies bring-up of the acquisition firmware before deployment in remote installations.
Recommended
Instrumentation and Test Equipment
Bench and portable instruments leverage the ATMEGA64-16AJ's JTAG on-chip debugging and boundary-scan capability, which accelerates firmware development and enables in-circuit test of populated assemblies. The 16 MHz throughput at 16 MIPS handles menu-driven HMI refresh, ADC sampling, and communication simultaneously, while the hardware PWM channels (OC0, OC1A/B/C, OC2) generate stimulus signals or backlight dimming. The internal bandgap-backed ADC reference provides a consistent 10-bit measurement baseline across the 4.5V to 5.5V supply range, and the analog comparator offers a fast threshold function. The two USARTs allow one port for a front-panel module and a second for PC connectivity, and the external memory bus can attach a large RAM bank for waveform capture buffers.
Recommended
Motor Control Systems
The ATMEGA64-16AJ supports motor control applications through its timer/PWM resources: one 8-bit timer (Timer0), one 16-bit timer (Timer1) with three compare channels, and an asynchronous-capable Timer2, providing up to four hardware PWM outputs suitable for H-bridge drive or servo signaling. The fast 16 MHz core executes closed-loop control at kilohertz rates using encoder inputs on the external interrupt pins and current feedback via the 8-channel 10-bit ADC. The 5V I/O drive is compatible with common gate-driver and logic-level MOSFET stages, and the JTAG interface allows real-time tuning of control parameters. Designers should pair the MCU with appropriate gate drivers and observe ADC sampling synchronization with PWM cycles to minimize switching-noise coupling into measurements.
Recommended
Communication and Protocol Converters
With two independent USARTs plus SPI and I2C on-chip, the ATMEGA64-16AJ is a natural protocol converter between legacy serial equipment and modern buses. One USART can run RS-232/RS-485 field protocols while the second links to a cellular or Ethernet module, and the 64KB Flash accommodates both protocol stacks plus buffering logic. The 16 MIPS throughput keeps interrupt latency low enough for deterministic serial timing, and hardware framing support in the AVR USART reduces CPU load. The external parallel bus can host dual-port RAM for zero-copy data exchange. Power from a single 5V rail simplifies integration into legacy cabinets, and the JTAG port permits field diagnosis of firmware during commissioning of installed converter networks.
Recommended
Legacy Board Redesigns and BOM Continuity
Many existing products were designed around the ATmega64 TQFP-64 footprint; the ATMEGA64-16AJ and its pin-compatible variants let engineers keep that qualified layout while refreshing sourcing. Because the ATMEGA64-16AU, ATMEGA64A-AU, and ATmega128-16AU all share the identical 64-TQFP pinout, a single PCB can accept any of these parts, providing a supply-chain hedge without respin. The self-programming Flash preserves field-update infrastructure from the original design, and the 5V logic levels match the legacy analog and display circuitry typically found on such boards. When redesigning, verify the A-die errata versus the original ATmega64 datasheet and re-run boundary-scan test vectors, since JTAG ID codes differ between die revisions.
Recommended
Recommended Products Summary
Engineering reference data for ATMEGA64-16AJ — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | ATMEGA64-16AU | ATMEGA64A-AU | ATMEGA64L-16AU | ATMEGA128-16AU |
|---|---|---|---|---|---|
| Package | 64-TQFP (14x14) | 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 Speed | 16 MHz | 16 MHz | 16 MHz | 16 MHz (at 5V) | 16 MHz |
| Flash Program Memory | 64 KB | 64 KB | 64 KB | 64 KB | 128 KB (+100%) |
| SRAM | 4 KB | 4 KB | 4 KB | 4 KB | 4 KB |
| EEPROM | 2 KB | 2 KB | 2 KB | 2 KB | 4 KB |
| Supply Voltage | 4.5 V to 5.5 V | 4.5 V to 5.5 V | 4.5 V to 5.5 V | 2.7 V to 5.5 V (clock derated below 5V) | 4.5 V to 5.5 V |
| JTAG Debug | Yes | Yes | Yes | Yes | Yes |
Key Differentiators
- Industrial temperature ordering code (vs ATMEGA64-16AU)
- Pin-compatible Flash upgrade path (vs ATMEGA128-16AU)
- External memory interface (vs ATMEGA328P-PU)
- Dual USART plus JTAG debug (vs ATMEGA32A-AU)
Design Notes
The -16 speed grade requires a 4.5V to 5.5V supply; below 4.5V the 16 MHz clock is out of specification and must be derated per the datasheet frequency-versus-voltage curve. Decouple each VCC pin (18, 40, 50, 59) with 100 nF ceramic capacitors placed within 2 mm of the pin, plus one 4.7 uF to 10 uF bulk capacitor per supply domain. Estimated: at 16 MHz with typical active current around 20 mA class (verify exact value in the manufacturer datasheet), a clean 5V rail with adequate decoupling keeps ADC reference noise low.
Keep the AREF node (pin 31) isolated: connect a 100 nF capacitor from AREF to GND close to the pin and route it away from switching nets. Use a solid ground plane under the TQFP-64 and stitch all four GND pins (19, 30, 49, 60) directly to it. The JTAG pins (PF4-PF7) double as ADC inputs; if ADC channels 4-7 are used, add series resistors or headers so a JTAG pod can be disconnected in production to avoid loading the analog inputs.
Enable the JTAGEN fuse consideration: with JTAG enabled, PC2-PC7 external-memory address lines are unaffected, but PF4-PF7 default to JTAG function after reset, which surprises designers who expect ADC4-ADC7. Also verify the M103C fuse compatibility fuse when migrating firmware from ATmega103. For self-programming bootloaders, ensure the BOOTSZ/BOOTRST fuses map the bootloader section before production programming, and confirm the RESET pin (64) is not left floating - use a 10 kΩ pull-up.
When the external memory bus (ALE on pin 61, WR/RD on 20/21, address port C) runs at 16 MHz, keep address trace lengths matched within a few centimeters and add 22-33 ohm series termination on ALE and data lines to limit ringing. Estimated: a 16 MHz square wave has significant harmonic energy near 96 MHz (5th harmonic), so a 4-layer board with a tight ground-return plane is strongly preferred over 2-layer for bus-driven designs.
Compliance Information
Compliance details not stated in the provided web data. Modern Microchip ATmega parts are generally RoHS/lead-free compliant, but per policy this must be confirmed from the official product page before claiming compliance.
