ATMEGA644P-A15MZ - 64KB AVR MCU, 16MHz, VQFN-44 | Microchip
MPN: ATMEGA644P-A15MZ β End of Life| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $2.81 | $2.81 |
| 10 | $2.6 | $26.00 |
| 100 | $2.4 | $240.00 |
| 500 | $2.2 | $1,100.00 |
| 1,000 | $2 | $2,000.00 |
ATMEGA644P-A15MZ Overview
An 8-bit AVR microcontroller is a complete computer-on-a-chip built around the AVR RISC core, combining program memory, data memory, timers, serial interfaces, and an ADC in a single IC. Within the power-management-free MCU hierarchy, it sits below 32-bit MCUs and above small 8-bit parts like the ATmega328, making it a mid-range embedded processor for control tasks.
Key features include dual USARTs for two independent serial links, an 8-channel 10-bit ADC for analog sensing, and a byte-oriented TWI (I2C) interface plus SPI for peripherals. 32 general-purpose I/O lines and three flexible timers with compare modes and PWM support motor control and LED driving. In-system programmability with read-while-write flash allows firmware updates on the final product.
The AVR architecture executes most instructions in a single clock cycle, delivering up to 16 MIPS throughput at 16 MHz. Harvard-architecture separate program and data buses, 32 general-purpose working registers, and a rich interrupt structure provide deterministic real-time behavior valued in automotive body electronics and industrial automation. JTAG and debugWIRE-style debug access simplifies software bring-up.
Typical applications include automotive body control modules, industrial sensor nodes, HVAC controllers, and motor-driven appliances. The dual USART and 10-bit ADC make it a fit for gateway nodes bridging analog sensors to serial networks.
When designing with this part, budget the 4KB SRAM carefully - stack, heap, and buffers share it - and use the brown-out detector plus watchdog timer for robust operation in electrically noisy vehicle environments.
This page synthesizes distributor pricing from LCSC and DigiKey, drop-in alternatives within the ATmega644P/644PA family, and practical design notes not found in the manufacturer datasheet.
Drop-in alternatives for ATMEGA644P-A15MZ β 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 ATMEGA644P-A15MZ (same form factor and footprint) β differing in EEPROM, Package, SRAM, Core Architecture, Packaging.
Quick Comparison Tool β Select alternative parts for side-by-side comparison:
ATMEGA644P-20MQ
β Drop-Inβ In Stock
$2.48 / Unit
View Datasheet βATMEGA644P-20MUR
β Drop-In β οΈ εζ°εΎ ιͺθ―π Reference alternative (not in catalog)
ATMEGA644PA-15MZ
β Drop-In β οΈ εζ°εΎ ιͺθ―π Reference alternative (not in catalog)
ATMEGA644PA-MUR
β Drop-In β οΈ εζ°εΎ ιͺθ―π Reference alternative (not in catalog)
ATMEGA644A-MUR
β Drop-In β οΈ εζ°εΎ ιͺθ―β In Stock
$4.31 / Unit
View Datasheet βATMEGA644P-A15MZ Maximum Ratings & Electrical Characteristics
| Core Processor | AVR |
| Core Size | 8-Bit |
| Max Clock Speed | 16 MHz |
| Flash Memory | 64 KB (32K x 16) |
| SRAM | 4 KB |
| EEPROM | 2 KB |
| Supply Voltage | 4.5 V to 5.5 V |
| Number of GPIO | 32 |
| USART | 2 |
| ADC Resolution | 10-bit |
| ADC Channels | 8 |
| Connectivity | I2C (TWI), SPI, UART/USART |
| Timers | 3 timers/counters with compare modes and PWM |
| Throughput | 16 MIPS at 16 MHz |
| Package | 44-VQFN (7x7 mm) |
| Mounting Type | Surface Mount |
| Qualification | AEC-Q100 (automotive) |
| Packaging | Tray |
ATMEGA644P-A15MZ 44-vqfn (7x7 mm) Pin Configuration Guide
Pin configuration for ATMEGA644P-A15MZ (44-vqfn (7x7 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 ATMEGA644P-A15MZ.
Refer to the datasheet for full pin configuration.
Typical Applications
ATMEGA644P-A15MZ is suitable for 6 applications: Automotive Body Control Modules, Industrial Sensor Nodes, HVAC and Building Automation Controllers, Motor Control and PWM Loads, Serial Gateways and Protocol Bridges, Appliance Control Panels.
Automotive Body Control Modules
The ATMEGA644P-A15MZ is explicitly AEC-Q100 qualified, making it suitable for automotive body electronics such as door modules, lighting controllers, and seat-position nodes. Its dual USARTs allow independent links to a vehicle LIN/UART bus and a diagnostic channel simultaneously, while the 8-channel 10-bit ADC digitizes switch inputs, potentiometer position, and analog fault monitoring. Operating from a 4.5V-5.5V regulated rail, the AVR core provides deterministic 16 MIPS execution for debounce logic and timing-critical PWM outputs. Because it is a mature part, use it to sustain existing automotive BOMs and rely on the ATmega644PA successor for new platforms requiring long-term supply.
Recommended
Industrial Sensor Nodes
In industrial sensing applications, the ATMEGA644P-A15MZ pairs its 8-channel 10-bit ADC with the TWI (I2C) interface to digitize and aggregate sensor arrays for temperature, pressure, and level monitoring. The 64KB flash holds communication stacks plus calibration tables, while the 2KB EEPROM stores non-volatile calibration coefficients and device IDs without external memory. Dual USARTs let one node bridge two serial networks, for example a Modbus RTU link and a local debug port. The 4.5V-5.5V supply matches legacy industrial 5V rails, and brown-out detection plus watchdog timers ensure autonomous recovery in electrically noisy factory environments.
Recommended
HVAC and Building Automation Controllers
The ATMEGA644P-A15MZ fits HVAC controllers that need multi-channel analog input and multiple serial links in one 5V device. Its three flexible timers generate PWM signals for fan and damper motor control, while the 10-bit ADC reads thermistors and humidity transmitters across eight channels. The TWI interface drives real-time clocks and EEPROM configuration chips, and a USART handles BACnet-lite or proprietary RS-485 links via external transceivers. With 32 GPIO lines, the same chip can directly drive relay columns and status LEDs, eliminating an I/O expander. The AEC-Q100 qualification additionally supports harsh outdoor rooftop unit environments.
Recommended
Motor Control and PWM Loads
The ATMEGA644P-A15MZ provides three timer/counters with compare modes and PWM outputs, enabling fan, pump, and small-motor control at 5V logic levels. Timer channels can drive half-bridge drivers through the PB4-PB7 and PD5-PD7 alternate-function pins, and the 16 MHz AVR core executes PI control loops deterministically at kHz rates. The 10-bit ADC samples motor current shunt voltages on up to eight channels for closed-loop current limiting, while external interrupts on INT0/INT1 capture quadrature encoder feedback. Its read-while-write flash supports in-field parameter updates, and the AEC-Q100 rating permits deployment in automotive blower and actuator modules.
Recommended
Serial Gateways and Protocol Bridges
With two independent USARTs, the ATMEGA644P-A15MZ is a natural serial gateway between systems such as an RS-232 service port and an RS-485 field bus, or between two Modbus segments. The 64KB flash accommodates buffering logic, protocol parsers for both directions, and logging structures in the 4KB SRAM, with 2KB EEPROM persisting routing tables and network addresses across power cycles. TWI and SPI interfaces extend the design with RTCs, displays, or external EEPROM for larger message stores. The 16 MHz throughput yields roughly 16 MIPS, comfortably handling 115200 baud bidirectional traffic with framing, CRC, and retry logic on both channels concurrently.
Recommended
Appliance Control Panels
Major appliances benefit from the ATMEGA644P-A15MZ combination of 32 GPIO, 10-bit ADC, and 5V operation. The GPIO directly scans membrane keypad matrices and drives segment LCD or LED displays via multiplexing, while the ADC reads thermistors for oven, washer, and refrigerator temperature regulation. Timer PWM channels control triac firing or heater duty cycles, and a USART provides a factory diagnostic port. The 64KB flash leaves generous headroom for localization strings and fault-log code. Its AEC-Q100 lineage reflects robust qualification against temperature and humidity stress, which translates well to the harsh thermal environment inside appliances.
Recommended
Recommended Products Summary
Engineering reference data for ATMEGA644P-A15MZ β comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | ATMEGA644P-20MQ | ATMEGA644PA-15MZ | ATMEGA644A-MUR |
|---|---|---|---|---|
| Brand | Microchip Technology (Atmel) | Microchip Technology | Microchip Technology | Microchip Technology |
| Package | 44-VQFN (7x7 mm) | 44-VQFN (7x7 mm) - same | 44-VQFN (7x7 mm) - same | 44-VQFN (7x7 mm) - same |
| Core / Bit Width | AVR, 8-bit | AVR, 8-bit | AVR, 8-bit | AVR, 8-bit |
| Max Clock Speed | 16 MHz | 20 MHz | 16 MHz | 20 MHz |
| Flash Memory | 64 KB | 64 KB | 64 KB | 64 KB |
| SRAM | 4 KB | 4 KB | 4 KB | 4 KB |
| USART Count | 2 | 2 | 2 | 1 |
| Lifecycle Status | Mature / NRND (replaced by ATmega644PA) | Mature / NRND | Active (recommended for new designs) | Active |
Key Differentiators
- Dual USARTs in the 644 family (vs ATMEGA644A-MUR)
- AEC-Q100 automotive qualification (vs ATMEGA328PB-AUR)
- Same footprint with lower-power successor available (vs ATMEGA644PA-15MZ)
Design Notes
The ATMEGA644P-A15MZ runs from a 4.5V-5.5V rail at its 16 MHz grade. Estimated: with typical active current in the low-tens of mA at 16 MHz and 5V, a clean linear or buck supply with at least 100 nF decoupling per VCC/AVCC pin plus 10 uF bulk is sufficient. Enable the internal brown-out detector around 4.3V so the MCU resets before flash corruption can occur during vehicle crank or industrial supply dips. Avoid running below 4.5V, as speed grade and ADC accuracy degrade below the specified range.
For the 44-VQFN (7x7 mm) land pattern, place 100 nF ceramic decoupling capacitors within 2 mm of each VCC and AVCC pin and connect the exposed center pad to a solid ground plane with a grid of vias. Keep the analog ground region for AREF/AVCC separated from noisy digital returns, tying them at a single star point. Route the two USART lines away from the crystal traces, and use a small ground guard around XTAL1/XTAL2 with 22 pF-class load capacitors selected per crystal datasheet. This mirrors Microchip's AVR hardware design app-note practice.
Three frequent mistakes with this family: (1) using all 4KB SRAM for buffers without reserving stack headroom - enable linker stack checks or watch for heap/stack collision; (2) exceeding the 4.5V minimum supply at 16 MHz, which causes marginal timing; (3) designing in the ATmega644P for new products - Microchip lists it as mature and not recommended for new designs, so qualify ATMEGA644PA equivalents early. Also note the ATmega644A substitutes have only one USART; pin-to-pin swaps must verify peripheral count against firmware requirements.
Compliance Information
AEC-Q100 automotive qualification per distributor series data (globalspec/icdirectory). The Z suffix in the ordering code denotes Microchip lead-free/green packaging. RoHS status per LCSC product data; REACH and conflict-minerals status not stated in provided data.