ATMEGA644PA-MU - 8-bit AVR MCU 64KB 20MHz VQFN-44 | Microchip
Référence : ATMEGA644PA-MU ✓ Actif| Qté | Prix unitaire | Total |
|---|---|---|
| 1 | $5.9 | $5,90 |
| 10 | $5.31 | $53,10 |
| 100 | $4.6 | $460,00 |
| 500 | $4.13 | $2 065,00 |
| 1 000 | $3.78 | $3 780,00 |
ATMEGA644PA-MU Présentation
An 8-bit AVR microcontroller is a single-chip processor built around an advanced RISC core in which most instructions execute in a single clock cycle, yielding approximately 1 MIPS per MHz. Within the power management and embedded control hierarchy, the ATmega family sits as a general-purpose flash microcontroller that integrates program memory, data memory, timers, serial interfaces, and an ADC on one die, replacing multi-chip MCU solutions in cost- and power-sensitive systems.
Key features of the ATMEGA644PA-MU include Microchip's picoPower technology for industry-leading low-power consumption, read-while-write Flash for self-programming, two programmable serial USARTs, a byte-oriented Two-Wire serial interface (I2C-compatible), an SPI serial interface, and three flexible timer/counters with compare modes and PWM. An 8-channel 10-bit ADC and a real-time counter (RTC) with a separate oscillator round out the peripheral set.
The advanced RISC architecture provides 131 powerful instructions, fully static operation, 32 x 8 general purpose working registers, and an on-chip 2-cycle hardware multiplier. In-system programmable (ISP) Flash with high endurance non-volatile memory segments supports field firmware updates, while the enhanced power-save modes make the part well suited to battery-powered designs.
Typical applications include industrial control and automation, sensor and data-logging nodes, consumer appliances, and battery-operated metering or monitoring products where 64 KB of program memory, rich peripherals, and low active/sleep current are required.
A key design consideration: the picoPower ATMEGA644PA achieves its lowest sleep currents only when unused peripherals and clock sources are disabled, and the 44-VQFN exposed pad should be soldered to a ground plane for thermal and signal-integrity performance.
This page synthesizes distributor availability, drop-in alternatives within the ATmega164A/324A/644A/1284 family, and practical design notes not found in the manufacturer datasheet. Pricing shown is estimated; verify current distributor pricing as of 2026-09-18 before ordering.
Alternatives de remplacement direct pour ATMEGA644PA-MU — même boîtier, compatible broche à broche. Les références à boîtier différent nécessitant une retouche du PCB sont exclues.
Variantes de cette série
Modèles de la même série directement compatibles avec ATMEGA644PA-MU (même facteur de forme et même empreinte) — différant par Package, EEPROM, SRAM, Flash Memory, RoHS Status.
Outil de comparaison rapide — sélectionnez des références alternatives pour une comparaison côte à côte :
ATMEGA644P-20MQ
✅ Remplacement direct✓ En stock
$2.48 / unité
Voir la fiche technique →ATMEGA644-20MU
✅ Remplacement direct📋 Alternative de référence (hors catalogue)
ATMEGA1284P-MU
✅ Remplacement direct ⚠️ Spécifications non vérifiées✓ En stock
$4.1 / unité
Voir la fiche technique →ATMEGA1284-MUR
✅ Remplacement direct ⚠️ Spécifications non vérifiées✓ En stock
$1.72 / unité
Voir la fiche technique →ATMEGA324A-MU
✅ Remplacement direct✓ En stock
$3.9 / unité
Voir la fiche technique →ATMEGA324PA-MU
✅ Remplacement direct ⚠️ Spécifications non vérifiées✓ En stock
$2.05 / unité
Voir la fiche technique →ATMEGA644PA-MU Valeurs maximales et caractéristiques électriques
| Core Architecture | 8-bit AVR RISC |
| Core Frequency | 20 MHz |
| Flash Memory | 64 KB (32K x 16) ISP Flash, read-while-write |
| EEPROM | 2 KB |
| SRAM | 4 KB |
| GPIO Count | 32 |
| MIPS Throughput | Up to 20 MIPS at 20 MHz |
| Instructions | 131 instructions, most single-cycle |
| Timer/Counters | Three flexible timer/counters with compare modes and PWM |
| USART | Two programmable serial USARTs |
| Serial Interfaces | Two-Wire Interface (I2C-compatible), SPI |
| ADC | 8-channel 10-bit ADC |
| RTC | Real Time Counter with separate oscillator |
| Low Power Technology | picoPower |
| Supply Voltage Range | 2.5 V / 3.3 V / 5 V class (per distributor listing: 2.5V/3.3V/5V) |
| Boîtier | 44-VQFN (7x7 mm), exposed pad |
| Type de montage | Surface Mount |
| Statut RoHS | RoHS compliant (per Microchip product listing) |
| Data Sheet Document Number | DS40002070A (per Microchip ATMEGA644PA-MU data sheet) |
Guide de configuration des broches du ATMEGA644PA-MU 44-vqfn (7x7 mm), exposed pad
Configuration des broches du ATMEGA644PA-MU (boîtier 44-vqfn (7x7 mm), exposed pad). Ce circuit intégré numérique comprend des GPIO, des interfaces de communication (UART, SPI, I2C) et des broches d'alimentation. Consultez la fiche technique du fabricant pour les fonctions alternatives des broches et les options de configuration. Indispensable pour la conception de systèmes embarqués et la conception de circuits imprimés.
Aucune donnée de brochage détaillée disponible pour ATMEGA644PA-MU.
Consultez la fiche technique pour la configuration complète des broches.
Applications typiques
ATMEGA644PA-MU convient pour 6 applications: Industrial Control and Automation, Battery-Powered Sensor and Data-Logging Nodes, Embedded Serial Communication Devices, Consumer Appliance Control Boards, Analog Sensing and Measurement Instruments, Motor Control and PWM Actuation Systems.
Industrial Control and Automation
The ATMEGA644PA-MU fits industrial control nodes because its 64 KB ISP Flash accommodates protocol stacks, state machines, and field-updatable firmware, while 4 KB SRAM supports buffering and multi-task control loops. Three timer/counters with compare modes and PWM drive actuators and motor control outputs directly, and the two USARTs connect to PLC backbones, HMI panels, or RS-485 transceivers. The 8-channel 10-bit ADC reads potentiometers, current shunts, and process sensors without external conversion silicon. Running at 20 MIPS, most control instructions execute in a single clock cycle for deterministic timing, and the fully static core tolerates wide clock ranges common on factory floors. Using the 44-VQFN footprint also allows migration to the 128 KB ATmega1284P-MU without PCB rework if application code grows.
Recommandé
Battery-Powered Sensor and Data-Logging Nodes
For battery-operated monitoring products, the ATMEGA644PA-MU's picoPower technology minimizes average current: the real-time counter with its separate oscillator can wake the MCU from power-save mode on a timed schedule, sample the 8-channel 10-bit ADC, timestamp to EEPROM, and return to a low-power sleep state. The 64 KB Flash stores logging firmware, tables, and compression routines, and the 4 KB SRAM buffers records between radio or UART transmissions. Two USARTs allow simultaneous connection to a sensor bus and a wireless or cellular module. Because the PA suffix denotes the lowest-power ATmega644 revision, designs consuming microamps in sleep benefit directly; verify the exact sleep-current figures in the Microchip electrical characteristics for your supply voltage before finalizing the power budget.
Recommandé
Embedded Serial Communication Devices
The ATMEGA644PA-MU is a strong fit for protocol converters, gateways, and communication adapters because it integrates two hardware USARTs plus a byte-oriented Two-Wire interface and SPI in one 44-pin device. A typical design bridges Modbus RTU on one USART to a proprietary two-wire bus on the other, while SPI drives an external EEPROM or display controller. The 64 KB ISP Flash with read-while-write lets the MCU reflash itself during field firmware updates without halting communication. Three timers generate baud-clock-independent PWM and timing references, and 32 GPIO lines handle flow control, addressing, and status signaling. The advanced RISC core delivers roughly 1 MIPS per MHz, so 20 MHz operation sustains wire-rate UART throughput at 115.2 kbaud with processing headroom.
Recommandé
Consumer Appliance Control Boards
In appliance control boards - washers, HVAC controllers, cooktops, and small kitchen equipment - the ATMEGA644PA-MU provides the right memory-to-pin-count balance: 64 KB Flash holds UI logic, fault tables, and multilingual strings, while 32 GPIO lines drive buttons, LEDs, relays, and stepper or BLDC motor PWM channels via the three timer/counters. The 10-bit ADC reads temperature sensors (NTC), pressure inputs, and user potentiometers across 8 channels. PicoPower modes keep standby current low for always-plugged products meeting standby-power expectations. The 44-VQFN (7x7 mm) exposed-pad package suits compact two-layer or four-layer control PCBs, and family pin compatibility with ATmega324A/1284P lets one PCB layout serve multiple product tiers with different memory grades.
Recommandé
Analog Sensing and Measurement Instruments
Handheld meters, environmental monitors, and portable test instruments benefit from the ATMEGA644PA-MU's combination of an 8-channel 10-bit ADC, 4 KB SRAM for waveform or sample buffering, and 64 KB Flash for calibration tables, linearization curves, and UI firmware. The real-time counter with separate oscillator maintains accurate time-stamping even when the main clock is stopped for power saving, and the on-chip 2-cycle hardware multiplier accelerates digital filtering and scaling math on the 8-bit core. Two USARTs output results to a PC, printer, or radio, while PWM channels drive piezo alerts and backlight control. Using the VQFN package keeps probe-sized instrument PCBs compact; the 44-pin footprint also supports the 128 KB ATmega1284P-MU for models requiring data-logging headroom.
Recommandé
Motor Control and PWM Actuation Systems
The ATMEGA644PA-MU suits DC and stepper motor controllers because three flexible timer/counters with compare modes generate independent PWM channels with dead-time-adjustable compare outputs, while the 2-cycle hardware multiplier speeds PID loop math on the 8-bit core. The 10-bit ADC samples current shunts and position potentiometers across 8 channels for closed-loop control, and 32 GPIO lines handle limit switches, direction pins, and fault inputs. At 20 MIPS the core sustains multi-kHz control-loop rates with interrupt headroom. The 64 KB Flash stores commutation tables and multiple motion profiles, and the Two-Wire interface connects to an EEPROM or host controller. Designers should verify ADC sampling jitter and PWM resolution requirements against the datasheet timer section for the target motor topology.
Recommandé
Récapitulatif des produits recommandés
Données de référence d'ingénierie pour ATMEGA644PA-MU — comparaison, recommandations de conception et informations de conformité.
Guide de sélection
Comparaison avec les alternatives
| Paramètre | Ce produit | ATMEGA644P-20MQ | ATMEGA644-20MU | ATMEGA324A-MU | ATMEGA1284P-MU |
|---|---|---|---|---|---|
| Package | 44-VQFN (7x7 mm) | 44-VQFN (7x7 mm) - same | 44-VQFN (7x7 mm) - same | 44-VQFN (7x7 mm) - same | 44-VQFN (7x7 mm) - same |
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Flash Memory | 64 KB | 64 KB | 64 KB | 32 KB | 128 KB |
| SRAM | 4 KB | 4 KB | 4 KB | 2 KB | 16 KB |
| EEPROM | 2 KB | 2 KB | 2 KB | 1 KB | 4 KB |
| Max CPU Frequency | 20 MHz | 20 MHz | 20 MHz | 20 MHz | 20 MHz |
| GPIO Count | 32 | 32 | 32 | 32 | 32 |
| Low Power Technology | picoPower (PA) | picoPower (P) | None (original die) | None (A die) | picoPower (P) |
Principaux différenciateurs
- picoPower die with lowest sleep currents in the 64 KB ATmega class (vs ATMEGA644-20MU)
- Twice the Flash and SRAM of the 324A in the identical 44-VQFN footprint (vs ATMEGA324A-MU)
- Cost-optimized mid-range position versus the 1284P (vs ATMEGA1284P-MU)
Notes de conception
The 44-VQFN (7x7 mm) MU package has an exposed pad that must be soldered to a ground pour. Use an array of thermal vias under the pad to tie it to internal ground planes - this serves as the primary ground return and improves heat dissipation. For hand assembly or rework, the 0.5 mm pitch QFN lands require a stencil with approximately 70-80% aperture reduction on the pads and sufficient paste on the center pad. Follow IPC-7351 land-pattern calculations or Microchip's QFN layout guidelines in the packaging section of the data sheet.
Decouple VCC and AVCC separately: place a 100 nF ceramic capacitor within 5 mm of each VCC/AVCC pin pair, plus a bulk 4.7-10 uF capacitor near the device. AVCC should be connected to VCC through a low-pass LC filter (for example a 10 uH inductor and 100 nF capacitor) when ADC accuracy matters, keeping the digital return currents out of the analog reference. Connect AREF to a decoupled reference (internal reference with 100 nF on AREF, or an external precision reference). Estimated: at 5 V and full 20 MHz active current, an LDO-fed supply should be sized with margin for inrush during ISP programming.
Sleep-mode current on the ATmega644PA is only achieved when unused peripherals and clock sources are explicitly disabled before entering sleep - leave an ADC or the watchdog running and the picoPower advantage disappears. Also note that RESET can be reconfigured as a weak I/O pin via the fuse bits; accidentally disabling the external reset fuse makes in-system programming impossible without high-voltage parallel programming. When migrating from the ATmega324A or the non-PA ATmega644, re-verify the sleep-mode and Brown-out detector current figures against the PA electrical characteristics rather than reusing older design calculations.
Keep the XTAL1/XTAL2 crystal traces as short as possible (under 10 mm) and surround them with a ground guard ring; load capacitors should match the crystal specification, typically 12-22 pF depending on the crystal's CL. Route the SPI and USART signals away from the crystal and ADC input traces. For the Two-Wire interface, use external pull-ups sized per bus capacitance (approximately 4.7 kiloohm at 5 V for short buses) since the TWI pins do not provide strong internal pull-ups. These practices prevent clock jitter on the ADC and UART framing errors at 20 MHz operation.
Informations de conformité
RoHS compliance and lead-free assembly are consistent with Microchip's standard product offering per the DigiKey/Microchip listings retrieved; REACH, halogen-free, and conflict-minerals statuses were not stated in the retrieved data and should be confirmed via Microchip's environmental page.