ATMEGA649-16AI - 8-Bit AVR MCU 16MHz 64KB Flash | Microchip
MPN: ATMEGA649-16AI ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $0 | $0.00 |
| 10 | $0 | $0.00 |
| 100 | $0 | $0.00 |
| 500 | $0 | $0.00 |
| 1,000 | $0 | $0.00 |
ATMEGA649-16AI Overview
An 8-bit AVR microcontroller is a Harvard-architecture RISC processor that executes most instructions in a single clock cycle, sitting at the low end of the embedded processing hierarchy below 32-bit MCUs but above dedicated logic. Microcontrollers of this class combine CPU, program memory, data memory, and peripherals in a single chip, serving as the central control element of an embedded system.
Key features include 130 powerful instructions with most executing in a single clock cycle, self-programming Flash with read-while-write capability for boot-loader applications, JTAG for on-chip debugging and boundary scan, and an on-chip LCD driver that offloads segment driving from software. The 54 general-purpose I/O lines available in the TQFP-64 package provide extensive connectivity to keypads, displays, and sensors.
Technically, the device belongs to the AVR ATmega family with 32 general-purpose working registers directly connected to the ALU, enabling single-cycle execution and code efficiency up to six times faster than conventional CISC MCUs. In-System Programming (ISP) allows firmware updates on the assembled board through SPI, while In-Circuit Serial Programming and debugging are supported via tools such as the MPLAB SNAP connected through an 8-pin SIL header.
Typical applications include consumer appliances with LCD user interfaces, metering products, industrial control panels, and battery-powered instruments, where the integrated LCD controller and low-power AVR core reduce board area and power consumption compared with a discrete LCD driver.
Design consideration: the LCD controller multiplexes a number of segment pins with general-purpose I/O, so pin budgeting must be completed early in the schematic capture process to avoid redesign.
This page synthesizes distributor pricing leads, drop-in family alternatives, and practical design notes not found in the manufacturer datasheet, as of 2026-09-18.
Drop-in alternatives for ATMEGA649-16AI — 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 ATMEGA649-16AI (same form factor and footprint) — differing in EEPROM, Operating Temperature, SRAM, Working Registers, Maximum Clock Frequency.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
ATMEGA645-16AI
✅ Drop-In✓ In Stock
$6.45 / Unit
View Datasheet →ATMEGA645V-8AI
✅ Drop-In✓ In Stock
Contact for price
View Datasheet →ATMEGA329-16AI
✅ Drop-In✓ In Stock
Contact for price
View Datasheet →ATMEGA325-16AI
✅ Drop-In ⚠️ 参数待验证📋 Reference alternative (not in catalog)
ATMEGA325V-8AI
✅ Drop-In ⚠️ 参数待验证✓ In Stock
$3.2 / Unit
View Datasheet →ATMEGA649-16AI 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, ISP, read-while-write |
| EEPROM Size | 2 KB |
| SRAM Size | 4 KB |
| Instruction Set | 130 powerful instructions, most single-cycle |
| General Purpose I/O | 54 I/O lines (TQFP-64 configuration) |
| Working Registers | 32 x 8-bit general purpose |
| JTAG | Yes (on-chip debug and boundary scan) |
| LCD Controller | On-chip segment LCD driver |
| Package | 64-TQFP (14x14 mm) |
| Mounting Type | Surface Mount |
| Operating Temperature | -40C to +85C (industrial grade, per Atmel part number suffix 'I') |
| RoHS Status | Compliant (per Microchip product listing) |
| Programming Interfaces | ISP (SPI), JTAG, ICSP via MPLAB SNAP |
ATMEGA649-16AI 64-tqfp (14x14 mm) Pin Configuration Guide
Pin configuration for ATMEGA649-16AI (64-tqfp (14x14 mm) package). This digital IC includes GPIO, communication interfaces (UART, SPI, I2C), and power pins. Refer to the manufacturer datasheet for alternate pin functions and configuration options. Essential for embedded system design and PCB layout.
No detailed pinout data available for ATMEGA649-16AI.
Refer to the datasheet for full pin configuration.
Typical Applications
ATMEGA649-16AI is suitable for 6 applications: Utility Metering with LCD Display, Consumer Appliance Control Panels, Industrial Control and HMI Nodes, Battery-Powered Portable Instruments, Building Automation and Access Control, Medical and Diagnostic Device UI Boards.
Utility Metering with LCD Display
Electricity, water, and gas meters require a low-power controller that can drive a numeric or bar-graph LCD for decades on battery or shunt-derived power. The ATMEGA649-16AI fits this role because its integrated segment LCD controller drives the display directly, eliminating a discrete LCD driver IC, while the AVR core at 16MHz handles measurement and communication tasks with mostly single-cycle instructions. Firmware can reside in the 64KB self-programming Flash with read-while-write support, enabling field firmware updates through a boot loader without interrupting the display. The 2KB EEPROM stores calibration and consumption totals across power loss. With 54 general-purpose I/O lines in the TQFP-64 package, tariff buttons, pulse outputs, and serial communication all fit on one chip.
Recommended
Consumer Appliance Control Panels
Ovens, washing machines, and climate-control appliances combine an LCD or segment display, a keypad matrix, and relay or triac actuation. The ATMEGA649-16AI addresses all three needs on one die: the on-chip LCD driver renders the user interface, the 16MHz AVR core with 130 single-cycle instructions executes the control state machine and safety interlocks deterministically, and the 54 I/O lines drive keypads and relays directly. The 4KB SRAM holds the UI state and task buffers, while the 2KB EEPROM retains user settings across power cycles. In-System Programming through SPI allows the same assembled PCB to be flashed with model-specific firmware at end-of-line, reducing the number of unique boards a manufacturer must stock and test.
Recommended
Industrial Control and HMI Nodes
Small industrial controllers and human-machine interface nodes need reliable firmware update paths, debugging infrastructure, and robust I/O. The ATMEGA649-16AI provides JTAG for on-chip debugging and boundary-scan testing of the assembled board, which shortens bring-up time and supports production test. The self-programming Flash with read-while-write capability allows a boot loader to receive new firmware over RS-485 or CAN while the application continues running, critical for equipment that cannot be powered down. The industrial temperature grade of -40C to +85C covers control-cabinet environments, and the 64KB Flash provides headroom for protocol stacks. The MPLAB SNAP tool connects via an 8-pin SIL header using two I/O pins plus reset for ICSP.
Recommended
Battery-Powered Portable Instruments
Handheld measurement and diagnostic instruments combine an LCD, buttons, and sensors, and must maximize runtime per charge. The ATMEGA649-16AI suits this class because the AVR core offers high code density and the LCD is driven by the low-power on-chip controller rather than software bit-banging, reducing average current. The device supports low-power sleep modes between measurements, and the 4KB SRAM buffers acquisition data without external memory. With the V-grade family members (ATMEGA325V-8AI, ATMEGA645V-8AI) sharing the same footprint, a design can be optimized for a lower supply voltage and 8MHz clock on the same PCB, trading processing speed for reduced active current in battery-critical variants.
Recommended
Building Automation and Access Control
Room controllers, thermostats, and access-control readers require a display, keypad, actuator driving, and persistent configuration storage. The ATMEGA649-16AI consolidates these requirements: the segment LCD controller drives the user display, the 54 GPIO lines handle keypad scanning and relay or lock actuation, and the 2KB EEPROM stores device addresses, credentials, and setpoints across power interruption. The 64KB self-programming Flash permits firmware and configuration updates in the field, an important serviceability feature for installed building equipment. The industrial -40C to +85C rating accommodates rooftop and unconditioned spaces. Firmware development is supported by the mature AVR toolchain and MegaCore open-source support for the ATmega649 device.
Recommended
Medical and Diagnostic Device UI Boards
Bench-top and portable medical devices such as blood-pressure monitors, glucose analyzers, and test instruments need a deterministic 8-bit control core driving a simple LCD interface, with auditable firmware. The ATMEGA649-16AI provides the on-chip LCD driver, 16MHz single-cycle-execution RISC core, and 4KB SRAM required for signal-chain coordination and display updates in a single TQFP-64 device, reducing component count on boards that must pass design reviews. JTAG enables boundary-scan production test and on-chip debugging during verification, supporting documentation-heavy development processes. The 2KB EEPROM retains calibration constants, and read-while-write Flash supports authenticated field updates. Longevity of the mature ATmega family simplifies long-term supply planning required in medical procurement.
Recommended
Recommended Products Summary
Engineering reference data for ATMEGA649-16AI — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | ATMEGA645-16AI | ATMEGA645V-8AI | ATMEGA329-16AI | ATMEGA325-16AI |
|---|---|---|---|---|---|
| Package | 64-TQFP (14x14 mm) | 64-TQFP (14x14 mm) - same | 64-TQFP (14x14 mm) - same | 64-TQFP (14x14 mm) - same | 64-TQFP (14x14 mm) - same |
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Core / Max Clock | AVR 8-bit / 16 MHz | AVR 8-bit / 16 MHz | AVR 8-bit / 8 MHz | AVR 8-bit / 16 MHz | AVR 8-bit / 16 MHz |
| Flash | 64 KB (32K x 16) | 64 KB | 64 KB | 32 KB | 32 KB |
| SRAM | 4 KB | 4 KB | 4 KB | 2 KB | 2 KB |
| EEPROM | 2 KB | 2 KB | 2 KB | 1 KB | 1 KB |
| LCD Controller | Yes (on-chip segment driver) | Yes | Yes | Yes | Yes |
| Temperature Grade | -40C to +85C (industrial) | -40C to +85C (industrial) | -40C to +85C (industrial) | -40C to +85C (industrial) | -40C to +85C (industrial) |
Key Differentiators
- Integrated segment LCD controller (vs ATMEGA64-16AU)
- Double the memory of the 32KB pin-compatible siblings (vs ATMEGA329-16AI)
- 16MHz full-speed grade over V-class variants (vs ATMEGA645V-8AI)
Design Notes
Reserve the SPI pins and RESET on a standard 8-pin SIL programming header as documented by Microchip for the MPLAB SNAP: the connector uses two device I/O pins plus the reset line to implement in-circuit debugging and ICSP. Adding series resistors on the SPI lines lets peripherals share these pins during normal operation without interfering with programming. Place the header at the board edge for fixture access in end-of-line flashing, since the self-programming Flash allows model-specific firmware to be loaded after assembly.
The LCD segment and common pins are multiplexed with general-purpose I/O among the 54 I/O lines in the TQFP-64 package. Before schematic freeze, build a pin-budget table assigning every LCD segment, keypad row/column, and communication pin, because enabling the LCD controller removes those pins from GPIO service. Also confirm which family member you are compiling for: ATmega325/329 devices have half the Flash, SRAM, and EEPROM of the ATmega649, and firmware that fits on a 649 with margin may overflow a pin-compatible 329 during a shortage substitution.
The -16 suffix denotes a 16MHz maximum clock and the standard voltage class; the V-class family members (e.g., ATMEGA645V-8AI) run at lower supply voltages but only 8MHz. If your design targets battery operation at reduced voltage, evaluate the same-footprint V-grade parts early, since the swap is pin-compatible and reduces active current. Decouple VCC and AVCC separately with 100nF ceramics at each supply pin pair and keep the LCD drive voltage rail clean, as LCD contrast depends on a stable bias.
Compliance Information
RoHS compliance and lead-free status per Microchip product listing and distributor data. REACH, halogen-free, and conflict-minerals status not stated in the provided data.
