ATMEGA649P-MU - 8-bit AVR MCU 64KB Flash LCD 16MHz | Microchip
MPN: ATMEGA649P-MU ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $6.2 | $6.20 |
| 10 | $5.58 | $55.80 |
| 100 | $4.96 | $496.00 |
| 500 | $4.4 | $2,200.00 |
| 1,000 | $3.91 | $3,910.00 |
ATMEGA649P-MU Overview
A microcontroller unit (MCU) is a single-chip computer that integrates a processor core, memory, and peripherals such as timers, USART, SPI, and analog comparators. The 8-bit AVR ATmega family sits within the broader microcontroller hierarchy (embedded processor -> microcontroller -> 8-bit MCU -> AVR ATmega), and the ATmega649P variant adds a segment LCD driver that many general-purpose MCUs lack, making it a complete human-interface solution on a single chip.
Key features include 64KB of in-system programmable Flash with read-while-write capability, 54/69 general purpose I/O lines, 32 general purpose working registers, and a JTAG interface for on-chip debugging and boundary-scan. The picoPower technology delivers industry-leading low power consumption across all sleep modes, supporting battery-powered designs. The integrated LCD controller can drive segmented displays directly, eliminating an external LCD driver IC.
Architecturally, the AVR core executes most instructions in a single clock cycle through its Harvard-architecture pipelining, achieving up to 16 MIPS at 16MHz. The device operates from a 1.8V to 5.5V supply, covering both battery and 5V industrial rails, and is rated for industrial temperature ranges.
Typical applications include utility metering with LCD displays, handheld measurement instruments, battery-operated industrial panels, and consumer appliances requiring segmented displays and long battery life.
When designing with this device, budget the Flash for both code and read-while-write data logging, and place a 0.1uF decoupling capacitor on each supply pin pair with a solid ground paddle connection under the QFN exposed pad.
This page synthesizes verified distributor pricing, drop-in family alternatives, and practical design guidance not found on the manufacturer datasheet alone.
Drop-in alternatives for ATMEGA649P-MU — 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 ATMEGA649P-MU (same form factor and footprint) — differing in Package, LCD Controller, Debug Interface, EEPROM, Operating Temperature.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
ATMEGA649A-MU
✅ Drop-In✓ In Stock
$4.42 / Unit
View Datasheet →ATMEGA329PA-MUR
✅ Drop-In ⚠️ 参数待验证✓ In Stock
$3.85 / Unit
View Datasheet →ATMEGA329PV-10MUR
✅ Drop-In ⚠️ 参数待验证✓ In Stock
$3.99 / Unit
View Datasheet →ATMEGA649PV-10MUR
✅ Drop-In ⚠️ 参数待验证📋 Reference alternative (not in catalog)
ATMEGA329PA-AUR
✅ Drop-In✓ In Stock
$5.94 / Unit
View Datasheet →ATMEGA649P-MU Maximum Ratings & Electrical Characteristics
| Core Processor | AVR |
| Core Size | 8-Bit |
| Speed | 16 MHz |
| Flash Memory | 64 KB (32K x 16) |
| EEPROM | 2 KB |
| SRAM | 4 KB |
| Connectivity | SPI, UART/USART |
| General Purpose I/O | 54 / 69 |
| LCD Controller | Yes (segment LCD driver) |
| Operating Voltage | 1.8 V to 5.5 V |
| Working Registers | 32 general purpose |
| Debug Interface | JTAG (on-chip debug, boundary scan) |
| Low Power Technology | picoPower |
| Package | 64-QFN (9x9 mm), MLF/VQFN |
| Mounting Type | Surface Mount |
| Temperature Range | Industrial (Ind Temp) |
| RoHS Status | Green (RoHS compliant) |
| Programming | ISP (In-System Programmable), read-while-write |
ATMEGA649P-MU 64-qfn (9x9 mm), mlf/vqfn Pin Configuration Guide
Pin configuration for ATMEGA649P-MU (64-qfn (9x9 mm), mlf/vqfn 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 ATMEGA649P-MU.
Refer to the datasheet for full pin configuration.
Typical Applications
ATMEGA649P-MU is suitable for 6 applications: Utility Metering (Energy / Water / Heat), Handheld Measurement Instruments, Industrial Control Panels with LCD, Battery-Powered Consumer Appliances, Data Loggers, Security and Access Control Terminals.
Utility Metering (Energy / Water / Heat)
The ATMEGA649P-MU fits utility metering because the integrated segment LCD controller drives tariff and consumption displays directly, while picoPower sleep modes extend battery service life to the meter's 10+ year target. The 64KB Flash with read-while-write capability supports metering firmware, load-profile logging, and field-upgradable bootloaders without an external memory chip. Placed between the battery and load with periodic wake-up from the asynchronous timer, the MCU samples sensors, updates LCD segments, and returns to deep sleep, keeping average current in the microamp range. The 1.8V floor allows operation through full battery discharge, and EEPROM stores calibration constants and billing data through power loss.
Recommended
Handheld Measurement Instruments
Handheld multimeters, panel meters, and environmental testers benefit from the ATMEGA649P-MU's combination of an on-chip LCD driver, 54/69 GPIO for keypad scanning, and a 1.8V to 5.5V supply range that tracks battery voltage directly without a boost converter. The AVR core executes most instructions in a single cycle, providing responsive user interfaces at up to 16MHz, while JTAG enables on-chip debugging during development. The 4KB SRAM accommodates measurement averaging buffers and logging, and the 2KB EEPROM preserves calibration data across battery replacement. With the LCD segments driven from the same supply, display contrast tracks the battery, and picoPower sleep modes preserve standby charge between measurements.
Recommended
Industrial Control Panels with LCD
In industrial HMI panels and controller front-ends, the ATMEGA649P-MU replaces the common MCU-plus-LCD-driver two-chip solution with a single 64-QFN device, cutting BOM cost and board area. The industrial temperature rating and 5V-tolerant operation at 5.5V match legacy industrial logic levels, while SPI and USART interfaces link to sensor front-ends, RS-485 transceivers, and host PLCs. The 64KB Flash hosts protocol stacks and localized text for the segmented or character LCD, and read-while-write Flash supports event logging. JTAG boundary scan aids production test of the densely populated panel PCB, and the 9x9 mm QFN keeps the layout compact behind the display glass.
Recommended
Battery-Powered Consumer Appliances
Thermostats, remote controls with displays, and kitchen appliances use the ATMEGA649P-MU for its picoPower sleep currents and integrated LCD drive, which are the two features that dominate battery life in such products. The MCU wakes from power-down via interrupt, scans a keypad matrix on its GPIO, updates LCD segments, and sleeps again; average system current can remain below a few microamps depending on duty cycle. The wide 1.8V to 5.5V input accepts two alkaline cells through end-of-life, and the 16MHz core handles motor or valve control loops when active. Firmware fits comfortably in 64KB Flash, leaving room for OTA-style bootloader updates over UART.
Recommended
Data Loggers
The ATMEGA649P-MU serves compact data-logger nodes by combining 64KB read-while-write Flash for in-Flash logging, 4KB SRAM for buffering, and picoPower modes for years of battery operation. Sensor channels connect through its ADC pins and GPIO, timestamps come from the asynchronous timer with a 32.768kHz crystal, and logged data streams out over the USART to a GSM/RS-485 link. Writing log records directly into Flash while executing code eliminates external EEPROM in many designs, and the 2KB EEPROM retains configuration through firmware updates. The 9x9 mm QFN suits dense PCB logging modules, and JTAG allows production calibration and boundary-scan test.
Recommended
Security and Access Control Terminals
Keypad-and-display access control terminals use the ATMEGA649P-MU's 54/69 GPIO to scan key matrices, drive relays or Wiegand interfaces, and render status on the integrated LCD without an external driver. The 64KB Flash stores code plus lookup tables and encrypted credential data, while EEPROM holds configuration and access lists through power cycles. The 16MHz single-cycle AVR core delivers fast keypad response and Wiegand pulse timing, and the USART interfaces to host panels over RS-485. PicoPower standby keeps mains-failure battery backup viable, and the industrial temperature rating supports outdoor reader enclosures mounted on gates and doors.
Recommended
Recommended Products Summary
Engineering reference data for ATMEGA649P-MU — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | ATMEGA649A-MU | ATMEGA329PA-MUR | ATMEGA329PV-10MUR | ATMEGA329PA-AUR |
|---|---|---|---|---|---|
| Package | 64-QFN (9x9 mm) | 64-QFN (9x9 mm) - same | 64-QFN (MLF) - same footprint | 64-QFN (MLF) - same footprint | TQFP-64 - pin-compatible die, different body |
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Flash Memory | 64 KB | 64 KB | 32 KB | 32 KB | 32 KB |
| SRAM | 4 KB | 4 KB | 2 KB | 2 KB | 2 KB |
| Max Speed | 16 MHz | 16 MHz | 20 MHz (PA grade) | 10 MHz | 20 MHz (PA grade) |
| LCD Controller | Yes | Yes | Yes | Yes | Yes |
| Operating Voltage | 1.8 V to 5.5 V | 1.8 V to 5.5 V | 1.8 V to 5.5 V | 1.8 V to 5.5 V (V low-voltage grade) | 1.8 V to 5.5 V |
| Product Status | Active | Active | Active | Active | Active |
Key Differentiators
- Full 64KB Flash and 4KB SRAM in the LCD-AVR family (vs ATMEGA329PA-MUR)
- Later silicon revision availability (vs ATMEGA649A-MU)
- 16MHz top speed versus low-voltage V-grades (vs ATMEGA329PV-10MUR)
Design Notes
The 64-QFN (9x9) exposed pad must be soldered to a ground paddle with an array of thermal vias; this pad is the primary ground and thermal path for the die. Place 0.1uF ceramic decoupling capacitors within 2 mm of each VCC/AVCC pin pair and one bulk 4.7uF to 10uF near the supply entry. Route the LCD segment traces away from the crystal and analog front-end to minimize capacitive coupling that distorts display contrast.
When running from batteries, exploit the picoPower modes: use power-down sleep with the asynchronous Timer/OSC32 clocked by a 32.768kHz crystal for wake-up timing, and disable the BOD or set it only during Flash writes. Estimated: a duty cycle of 10 ms active per second at roughly 10 mA active current gives an average near 100 uA before LCD drive current - a 2000 mAh cell would then last well over a year. Verify exact currents against the datasheet electrical-characteristics tables for your voltage and clock combination.
AVR maximum clock frequency derates with supply voltage: above 8MHz the part requires a higher supply (see the speed-versus-voltage curve in the manufacturer datasheet). Do not clock 16MHz from a 2-cell battery at 2.7V. Also confirm JTAG is disabled or fused appropriately if the four JTAG pins are needed as GPIO in production, and plan MSL/floor-life handling for the moisture-sensitive QFN package before reflow.
Compliance Information
Distributor listings (FindIC, DigiKey) describe the part as Green, indicating Microchip's lead-free, halogen-free RoHS-compliant packaging. REACH and conflict-minerals declarations should be requested from Microchip directly.
