ATSAM3N2BA-MU - 48MHz Cortex-M3 MCU, 128KB Flash | Microchip
MPN: ATSAM3N2BA-MU β Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $4.35 | $4.35 |
| 10 | $4.15 | $41.50 |
| 100 | $3.87 | $387.00 |
| 500 | $3.55 | $1,775.00 |
| 1,000 | $3.25 | $3,250.00 |
ATSAM3N2BA-MU Overview
A microcontroller (MCU) is a single integrated circuit that combines a processor core, memory, and programmable peripherals into one chip, forming the lowest layer of the embedded systems hierarchy: embedded system -> microcontroller -> ARM Cortex-M core family. The ATSAM3N2BA-MU belongs to Microchip's (formerly Atmel's) SAM3N series, which is based on the high-performance 32-bit ARM Cortex-M3 RISC processor and is pin-to-pin compatible with the SAM3S series, offering an ideal migration path for applications requiring reduced BOM cost.
Key features include the ARM Cortex-M3 revision 2.0 core with Thumb-2 instruction set, a 24-bit SysTick counter, and a Nested Vector Interrupt Controller (NVIC). The peripheral set comprises 2x USARTs, 2x UARTs, 2x TWI (I2C) interfaces, 3x SPI interfaces, 1 PWM timer, 6x general-purpose 16-bit timers, an RTC, and a 10-bit ADC. An internal oscillator removes the need for an external crystal in many designs, cutting component cost.
Technically, the SAM3N series was engineered for cost-sensitive, high-volume applications; its aggressive price point and high integration push its scope of use far into consumer and industrial volume products. The Thumb-2 instruction set delivers high code density, reducing flash requirements per function.
Typical applications include industrial control panels, consumer appliances, metering equipment, and cost-sensitive IoT sensor nodes where 128KB flash and rich serial connectivity are sufficient.
When designing with this device, note the 1.62V to 3.6V supply range permits direct battery operation, and the internal oscillator eliminates the external crystal for non-timing-critical UART applications.
This page synthesizes distributor pricing, drop-in same-family alternatives, and practical design notes not found in the manufacturer datasheet.
Drop-in alternatives for ATSAM3N2BA-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 ATSAM3N2BA-MU (same form factor and footprint) β differing in RoHS Status, Core Processor, Packaging, Series, Flash Memory Size.
Quick Comparison Tool β Select alternative parts for side-by-side comparison:
ATSAM3S2BA-MU
β Drop-Inπ Reference alternative (not in catalog)
ATSAM3N4BA-MU
β Drop-In β οΈ εζ°εΎ ιͺθ―β In Stock
$3.48 / Unit
View Datasheet βATSAM3N1BA-MU
β Drop-In β οΈ εζ°εΎ ιͺθ―π Reference alternative (not in catalog)
ATSAM4LS2BA-MU
β Drop-Inβ In Stock
$3.79 / Unit
View Datasheet βATSAM3N2BA-MU Maximum Ratings & Electrical Characteristics
| Core Processor | ARM Cortex-M3 revision 2.0 |
| Core Size | 32-bit |
| Maximum Clock Speed | 48 MHz |
| Flash Memory Size | 128KB (128K x 8) |
| SRAM Size | 16K x 8 |
| Supply Voltage Range | 1.62 V to 3.6 V |
| Number of I/O | 47 |
| Package / Case | 64-QFN (9x9 mm) with exposed pad |
| Oscillator Type | Internal |
| Peripherals | PWM timer, RTC, 10-bit ADC, DMA |
| Connectivity | 2x USART, 2x UART, 2x TWI, 3x SPI |
| Timers | 6x general-purpose 16-bit timers |
| Instruction Set | Thumb-2 |
| Temperature Grade | Industrial |
| Mounting Type | Surface Mount |
| Packaging | Tray |
| Series | SAM3N |
| Compatibility | Pin-to-pin compatible with SAM3S series (48/64/100-pin) and SAM7S legacy products (48/64-pin) |
| RoHS Status | Compliant (green package) |
ATSAM3N2BA-MU 64-qfn (9x9 mm) with exposed pad Pin Configuration Guide
Pin configuration for ATSAM3N2BA-MU (64-qfn (9x9 mm) with exposed pad 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 ATSAM3N2BA-MU.
Refer to the datasheet for full pin configuration.
Typical Applications
ATSAM3N2BA-MU is suitable for 6 applications: Industrial Control Panels, Consumer Appliances, Metering and Energy Monitoring, IoT Sensor Nodes, Motor and Fan Control Boards, Human-Machine Interfaces (HMI).
Industrial Control Panels
The ATSAM3N2BA-MU suits industrial control panels because its 47 general-purpose I/O lines, 6x general-purpose 16-bit timers, and RTC cover the mixed digital-I/O and timing requirements of relay sequencing, keypad scanning, and event logging. The industrial temperature grade ensures operation in unconditioned cabinets, and the wide 1.62V to 3.6V supply range tolerates noisy 3.3V rails. Serial connectivity (3x SPI, 2x USART) links HMI displays and RS-485 transceivers. Using the internal oscillator for non-critical timing eliminates one crystal, reducing BOM cost in high-volume panels. Placed near the backplane with local 100nF decoupling per power pin plus a 10uF bulk capacitor, the Cortex-M3 core at 48 MHz delivers ample headroom for control loops without a higher-cost MCU class.
Recommended
Consumer Appliances
Cost-sensitive, high-volume consumer appliances such as coffee machines, air purifiers, and small kitchen devices are the target market Atmel identified for the SAM3N series, described in the datasheet as pushing 'aggressive price point and high level of integration' far into cost-sensitive applications. The ATSAM3N2BA-MU's 128KB flash holds control firmware plus a simple UI, the 10-bit ADC reads thermistors and potentiometers, and the PWM timer drives heater or fan control. The internal oscillator removes the external crystal for non-timing-critical designs, cutting component count further. The 64-QFN 9x9 mm exposed-pad package provides a compact footprint for tightly packed control boards, and pin compatibility with SAM3S allows a cost-down swap or a feature-up swap without a PCB respin.
Recommended
Metering and Energy Monitoring
Electricity, water, and heat meters benefit from the ATSAM3N2BA-MU's RTC for timestamping consumption records, its 10-bit ADC for auxiliary analog measurements, and its USARTs for communication with metering bus transceivers or optical probes. The 128KB flash stores metrology firmware and calibration tables, while 16KB SRAM holds buffer data between communication sessions. The RTC keeps time even in low-power sleep, and the Cortex-M3's low active current suits battery-backed meter variants. Industrial temperature rating supports outdoor meter enclosures. The SAM3N series' pin-to-pin compatibility with SAM3S lets metering OEMs share one PCB across product tiers, populating either the cost-optimized ATSAM3N2BA-MU or a SAM3S variant where more integrated peripherals are needed.
Recommended
IoT Sensor Nodes
Wired and low-data-rate IoT sensor nodes use the ATSAM3N2BA-MU to bridge sensors to a gateway: the 2x TWI (I2C) interfaces read humidity, pressure, and light sensors, the 10-bit ADC samples analog sensors, and a USART connects to a radio or Ethernet module. The Cortex-M3's Thumb-2 code density keeps protocol stacks inside 128KB flash, and the low supply range of 1.62V to 3.6V allows direct operation from a 3.6V lithium cell or a 3.3V rail. Sleep modes and the ability to run from the internal oscillator minimize standby current. The 64-QFN 9x9 mm package keeps node PCBs small. For designs expecting firmware growth, the pin-compatible ATSAM3N4BA-MU with 256KB flash provides an upgrade path on the same PCB.
Recommended
Motor and Fan Control Boards
The ATSAM3N2BA-MU drives small brushed and brushless motor control boards using its 6x general-purpose 16-bit timers to generate complementary PWM and its 10-bit ADC to monitor current via a shunt. The 48 MHz Cortex-M3 executes commutation and closed-loop speed control with adequate margin, while the PWM timer adds independent output channels for fan or heater modulation. Three SPI interfaces simplify attaching gate drivers or serial diagnostics. Because this MCU family is pin-to-pin compatible across SAM3N and SAM3S, control boards can be qualified once and populated with the memory tier each model needs. Place the MCU away from the power stage with a solid ground plane to the exposed pad to keep ADC readings clean from switching noise.
Recommended
Human-Machine Interfaces (HMI)
Keypad-and-display HMIs leverage the ATSAM3N2BA-MU's combination of 47 I/O lines for matrix keypads and indicator LEDs, plus 2x USART, TWI, and SPI ports for character LCDs, OLED modules, and touch controllers. The 128KB flash accommodates localization string tables and event logging, and the RTC provides date/time display without external components. The industrial temperature grade supports both factory-floor terminals and outdoor kiosks. Designers can use one SPI port at high speed for the display and reserve the remaining serial ports for a printer or barcode scanner. The cost-reduced SAM3N positioning makes it attractive against application-specific display drivers, and the SAM3S pin-compatible family provides a path if more advanced touch or graphics peripherals are needed later.
Recommended
Recommended Products Summary
Engineering reference data for ATSAM3N2BA-MU β comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | ATSAM3S2BA-MU | ATSAM3N4BA-MU | ATSAM3N1BA-MU | ATSAM4LS2BA-MU |
|---|---|---|---|---|---|
| Package | 64-QFN (9x9 mm) | 64-QFN (9x9 mm) - same | 64-QFN (9x9 mm) - same | 64-QFN (9x9 mm) - same | 64-QFN (9x9 mm) - same |
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Core | ARM Cortex-M3, 48 MHz | ARM Cortex-M3, 48 MHz | ARM Cortex-M3, 48 MHz | ARM Cortex-M3, 48 MHz | ARM Cortex-M4, 48 MHz |
| Flash Memory | 128KB | 128KB | 256KB | 64KB | 128KB |
| Series Positioning | SAM3N cost-optimized | SAM3S higher integration | SAM3N, larger flash | SAM3N, lowest flash/cost | SAM4L ultra-low-power |
| Firmware Compatibility | SAM3N baseline | Near-identical peripheral set | Identical (same family) | Identical (same family) | Different register set |
| Drop-in on Same PCB | Reference footprint | Yes (datasheet pin-to-pin compatible) | Yes (same family, 64-pin) | Yes (same family, 64-pin) | Verify pin map before use |
Key Differentiators
- Lowest BOM cost within a pin-compatible family (vs ATSAM3S2BA-MU)
- Pin-compatible flash upgrade path (vs ATSAM3N4BA-MU)
- Same-package ultra-low-power option (vs ATSAM4LS2BA-MU)
Design Notes
Supply the ATSAM3N2BA-MU from a single rail within its 1.62V to 3.6V specification; 3.3V is the standard choice for full-speed 48 MHz operation. Decouple each VDD pin pair with 100nF ceramic capacitors placed within 2 mm of the pins, plus one 4.7uF to 10uF bulk capacitor near the package. Connect the exposed pad of the 64-QFN to a solid ground plane for both thermal dissipation and return-current integrity. Estimated: at 48 MHz typical active current for this Cortex-M3 class (tens of mA), a 3.3V rail with 50mA load dissipates roughly 165 mV-equivalent load on the regulator - well within typical LDO capability.
Do not assume SAM3S and SAM3N peripherals are register-identical: the datasheet states pin-to-pin compatibility, but SAM3N omits some SAM3S peripherals, so firmware written for ATSAM3S2BA-MU may reference missing registers. Before dropping in ATSAM3S2BA-MU or moving code between families, re-verify the peripheral mapping in the SAM3N datasheet. Also confirm that any code relying on the exact flash and SRAM sizes (128KB/16KB) fits the smaller ATSAM3N1BA-MU if a cost-down swap is planned, and that bootloader offsets match the flash density.
The 64-QFN (9x9 mm) exposed-pad package requires a correctly designed land pattern with thermal vias under the exposed pad (typically a 3x3 via array) to solder reliably and conduct heat into inner ground planes. Follow IPC-recommended QFN land-pattern geometry for the 0.5 mm pitch leads and extend solder mask openings per Microchip's package drawing in the datasheet. Keep high-speed SPI and USART traces short, and route the analog ADC inputs away from switching nodes; use a dedicated quiet analog supply feed with an RC filter if ADC accuracy matters.
Compliance Information
Green, industrial-temperature, MRL A package per distributor listings (Utmel, atmel-micro.com). Not an automotive AEC-Q100 part. REACH and conflict-minerals status not stated in the provided data.
