ATSAM3N4AA-MU - Cortex-M3 48MHz 256KB Flash MCU | Microchip
MPN: ATSAM3N4AA-MU β Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $5.98 | $5.98 |
| 10 | $5.45 | $54.50 |
| 100 | $4.98 | $498.00 |
| 500 | $4.5 | $2,250.00 |
| 1,000 | $4.1 | $4,100.00 |
ATSAM3N4AA-MU Overview
A microcontroller (MCU) is a single-chip computer that integrates a processor core, memory, and peripherals such as UARTs, timers, and ADCs. Within the embedded hierarchy, the SAM3N family belongs to the ARM Cortex-M3 class of 32-bit microcontrollers, positioned above 8-bit MCUs like the PIC16 series and alongside other Cortex-M parts such as the ATSAM4 and ATSAML21 families. The SAM3N is the cost-optimized sibling of the SAM3S, targeting cost-sensitive, high-volume embedded applications.
Key differentiating features include the Cortex-M3 revision 2.0 core executing Thumb-2 instructions, a 24-bit SysTick timer, and a Nested Vector Interrupt Controller (NVIC) for deterministic interrupt handling. The 256 KB Flash uses a 128-bit-wide access bus with a memory accelerator to sustain full-speed 48 MHz execution, while the 24 KB SRAM supports modest buffering stacks and communication buffers. Supply operation spans 1.62 V to 3.6 V, enabling single 3.3 V-rail designs.
Technically, the SAM3N series achieves its reduced BOM cost by streamlining the SAM3S peripheral set while retaining the same pinout. It is pin-to-pin compatible with SAM3S (48-, 64-, and 100-pin versions) and with legacy SAM7S 48- and 64-pin products, giving designers a documented migration path in both directions. Internal RC oscillators allow clocking without an external crystal for non-timing-critical applications.
Typical applications include industrial sensors and actuators, building automation nodes, consumer appliance control, and battery-powered metering products where cost and low pin count matter more than maximum connectivity.
When designing, budget the 34 I/O carefully - the 48-QFN package lacks the port expansion of the 64- and 100-pin siblings, so peripheral multiplexing decisions should be made before layout.
This page synthesizes distributor pricing, drop-in alternatives across the SAM3N/SAM3S families, and practical design notes not found in the manufacturer datasheet.
Drop-in alternatives for ATSAM3N4AA-MU 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 ATSAM3N4AA-MU (same form factor and footprint) β differing in SRAM, Pin Compatibility, Core Processor, Series, Operating Temperature.
Quick Comparison Tool β Select alternative parts for side-by-side comparison:
No drop-in alternatives available for this product.
Request AlternativesATSAM3N4AA-MU Maximum Ratings & Electrical Characteristics
| Core Processor | ARM Cortex-M3 revision 2.0 |
| Core Size | 32-bit |
| Maximum Clock Speed | 48 MHz |
| Program Memory Size | 256 KB (256K x 8) |
| Program Memory Type | FLASH |
| RAM Size | 24 KB (24K x 8) |
| Number of I/O | 34 |
| Supply Voltage Range | 1.62 V to 3.6 V |
| Oscillator Type | Internal |
| Instruction Set | Thumb-2 |
| SysTick Timer | 24-bit |
| Interrupt Controller | Nested Vector Interrupt Controller (NVIC) |
| Package / Case | 48-QFN (7x7 mm) |
| Mounting Type | Surface Mount |
| Series | SAM3N |
| Pin Compatibility | SAM3S (48/64/100-pin) and SAM7S (48/64-pin) |
ATSAM3N4AA-MU 48-qfn (7x7 mm) Pin Configuration Guide
Pin configuration for ATSAM3N4AA-MU (48-qfn (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 ATSAM3N4AA-MU.
Refer to the datasheet for full pin configuration.
Typical Applications
ATSAM3N4AA-MU is suitable for 6 applications: Industrial Sensor Nodes, Building Automation Controllers, Consumer Appliance Control, Battery-Powered Metering, Legacy SAM7S Migration, IoT Sensor Endpoints.
Industrial Sensor Nodes
The ATSAM3N4AA-MU fits industrial sensor nodes because its 48 MHz Cortex-M3 core provides enough processing headroom for filtering and scaling of ADC data, while the 256 KB Flash accommodates protocol stacks and calibration routines without external memory. Its 34 I/O lines cover sensor interfaces, status LEDs, and local actuators in a compact 7x7 mm QFN footprint. The wide 1.62 V to 3.6 V supply range tolerates noisy industrial 3.3 V rails, and the internal oscillator allows crystal-free designs where timing accuracy requirements are modest. Placed at the node's front end reading analog sensors through the on-chip ADC and reporting over UART or SPI to a gateway, the MCU reduces BOM cost in volume deployments - the core value proposition of the SAM3N series over the fuller-featured SAM3S.
Recommended
Building Automation Controllers
In building automation - damper control, occupancy-driven lighting, and HVAC zone controllers - the ATSAM3N4AA-MU offers a balanced profile: the Cortex-M3 executes control loops deterministically under the NVIC, and 24 KB SRAM buffers communication frames for protocols such as Modbus RTU over UART. The 48 MHz maximum clock keeps loop latency low while the Thumb-2 instruction set yields compact code within the 256 KB Flash, leaving headroom for field-updatable firmware. Its 34 GPIOs directly drive relays, triac drivers, and keypads without port expanders, and the 48-QFN 7x7 mm package supports compact controller PCBs. Because the SAM3N is pin-to-pin compatible with SAM3S, a single controller PCB can be populated with either part to create product tiers at different price points.
Recommended
Consumer Appliance Control
Consumer appliances such as coffee machines, fan heaters, and small kitchen devices demand low unit cost, adequate performance, and straightforward certification - precisely the SAM3N series positioning. The ATSAM3N4AA-MU's 48 MHz Cortex-M3 handles user-interface scanning, display multiplexing, and control algorithms comfortably, while the internal oscillator eliminates crystal cost for applications without precise timing needs. The 256 KB Flash allows generous UI code, multiple language tables, and safe firmware-update schemes; cost-sensitive sub-models can share the same PCB with the 64 KB ATSAM3N1AA-MU. Operating from a single 3.3 V rail with 1.62 V low-end tolerance simplifies the power supply, and the 48-QFN package keeps the controller area small on dense appliance PCBs.
Recommended
Battery-Powered Metering
Energy and water metering products benefit from the ATSAM3N4AA-MU's combination of low-cost architecture and low-power operating modes. The Cortex-M3 can wake from low-power sleep states via the NVIC, process a measurement burst at 48 MHz, and return to sleep, while the internal RC oscillator supports clock-tolerant wake strategies without continuous crystal drive current. The 1.62 V supply floor allows operation directly from a depleted 3 V lithium cell through a simple regulator, and 256 KB Flash holds multi-year logging tables and tariff logic within the 24 KB SRAM buffer budget. Designers should consult the datasheet electrical characteristics for per-mode current figures and size the battery accordingly, since SAM3N power consumption is optimized for cost rather than ultra-low-power records.
Recommended
Legacy SAM7S Migration
The ATSAM3N4AA-MU is explicitly pin-to-pin compatible with Atmel's legacy SAM7S products in 48- and 64-pin versions, making it the documented upgrade path for aging ARM7TDMI designs facing end-of-life risk. A SAM7S board can typically adopt the SAM3N with footprint-level hardware changes limited to power-supply review, since the Cortex-M3 runs at 48 MHz versus the ARM7's lower clock and the memory map and peripheral register interfaces differ. Firmware must be ported, but the Thumb-2 instruction set generally compiles legacy C code with modest changes. Migrating gains a modern core revision 2.0, Flash acceleration via 128-bit wide access, and an active supply roadmap under Microchip Technology, securing long-term sourcing for high-volume legacy products.
Recommended
IoT Sensor Endpoints
For IoT endpoints that pair a local MCU with a radio module, the ATSAM3N4AA-MU serves as the application controller: its UART and SPI ports interface to Wi-Fi, LoRa, or BLE modules, while the 34 GPIOs handle sensors and local indication. The 48 MHz Cortex-M3 preprocesses data - packetizing, encrypting, and filtering - before transmission, reducing radio duty cycles and conserving energy in battery nodes. The 256 KB Flash supports over-the-air update staging within a dual-image scheme, and the 48-QFN 7x7 mm package keeps the controller small beside the radio footprint. The wide 1.62 V to 3.6 V operating range simplifies integration with single-cell lithium or three-cell alkaline supplies. For designs where SAM3N cost advantages matter at scale, it is a pragmatic endpoint controller choice.
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Recommended Products Summary
Engineering reference data for ATSAM3N4AA-MU β comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | ATSAM3S4AA-MU | ATSAM3S2AA-MU | ATSAM3N2AA-MU | ATSAM3N1AA-MU |
|---|---|---|---|---|---|
| Package | 48-QFN (7x7 mm) | 48-QFN (7x7 mm) - same | 48-QFN (7x7 mm) - same | 48-QFN (7x7 mm) - same | 48-QFN (7x7 mm) - same |
| Brand | Microchip Technology (Atmel) | Microchip Technology (Atmel) | Microchip Technology (Atmel) | Microchip Technology (Atmel) | Microchip Technology (Atmel) |
| Core | ARM Cortex-M3 rev 2.0, 48 MHz | ARM Cortex-M3, 48 MHz | ARM Cortex-M3, 48 MHz | ARM Cortex-M3, 48 MHz | ARM Cortex-M3, 48 MHz |
| Flash | 256 KB | 256 KB | 128 KB | 128 KB | 64 KB |
| Supply Voltage | 1.62 V to 3.6 V | 1.62 V to 3.6 V | 1.62 V to 3.6 V | 1.62 V to 3.6 V | 1.62 V to 3.6 V |
| Peripheral Set | SAM3N (cost-optimized) | SAM3S (richer set, e.g. USB on some variants) | SAM3S (richer set) | SAM3N (same as this product) | SAM3N (same as this product) |
Key Differentiators
- Cost-optimized peripheral set at same footprint (vs ATSAM3S4AA-MU)
- Maximum Flash in the pin-compatible SAM3N 48-pin family (vs ATSAM3N2AA-MU)
- Documented legacy migration path (vs Legacy SAM7S parts)
Design Notes
Design the power tree around the 1.62 V to 3.6 V supply range with a nominal 3.3 V rail. Decouple each VDD/VDDIO pin pair with 100 nF ceramic capacitors placed within 2 mm of the pins, plus one bulk 4.7 uF to 10 uF capacitor near the device. Note the SAM3N lacks some SAM3S peripherals, so verify total I/O current draw against the datasheet maximum per-port and total-device current limits before finalizing the regulator, especially when driving multiple LEDs or relays from GPIOs.
The 48-QFN (7x7 mm) package has a central exposed pad that must be soldered to a grounded thermal land with an array of vias to the ground plane - this provides the primary ground connection and improves thermal and electrical performance. Follow the land pattern in the manufacturer datasheet package section, avoid solder-mask over the thermal pad aperture, and use pin 1 index marker orientation matching the silkscreen. Place the SWD debug header traces (SWDIO/SWCLK) accessible for programming.
Do not assume SAM3S firmware peripherals map one-to-one onto the SAM3N: while pin-to-pin compatible, the SAM3N removes certain peripherals to achieve its lower price, so register-level code written for SAM3S must be re-validated. The internal oscillator is convenient but has looser frequency accuracy than a crystal - use an external crystal when UART baud rates, USB (on SAM3S), or precise timing matter. Also verify Flash capacity headroom: 256 KB fills faster than expected with Thumb-2 debug builds; reserve 20-30% margin for field updates.
Compliance Information
RoHS/lead-free status per standard Microchip current production; REACH, halogen-free, and conflict-minerals declarations should be confirmed against Microchip's official environmental documentation for the specific date code.
