ATSAM3N1BB-MUR - 48MHz Cortex-M3 MCU 64KB Flash | Microchip
MPN: ATSAM3N1BB-MUR β Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $3.42 | $3.42 |
| 10 | $3.08 | $30.80 |
| 100 | $2.74 | $274.00 |
| 500 | $2.45 | $1,225.00 |
| 1,000 | $2.18 | $2,180.00 |
ATSAM3N1BB-MUR Overview
A microcontroller (MCU) is a single integrated circuit that combines a processor core, memory, and programmable peripherals into one chip, forming the brain of embedded systems. Within the power/performance hierarchy, the SAM3N series sits between entry-level 8-bit MCUs and higher-performance SAM4/SAM7 parts, offering 32-bit compute with ARM Cortex-M3 RISC architecture at an aggressive price point. According to Microchip, the SAM3N series is pin-to-pin compatible with the SAM3S series, enabling straightforward migration paths.
Key features include a 48 MHz Cortex-M3 core, 64KB single-cycle flash memory, 8KB SRAM, and connectivity peripherals comprising I2C (TWI), SPI, UART/USART, and IrDA serial communication. The device operates from a single supply of 1.62V to 3.6V (with 1.8V, 2.5V, and 3.3V typical rails), making it suitable for battery-powered designs. It is ready for capacitive touch through the Microchip QTouch library, supporting buttons, wheels, and sliders without external components.
Technically, the Cortex-M3 core provides a 3-stage pipeline, Thumb-2 instruction set, and a Nested Vectored Interrupt Controller (NVIC) for deterministic interrupt handling, while the flash accelerator keeps effective performance close to the 48 MHz clock rate. The 64-QFN package with exposed pad offers good thermal and electrical performance in a 9x9 mm footprint for space-constrained boards.
Typical applications include industrial control boards, consumer appliances, metering and sensing nodes, and capacitive-touch user interfaces. The combination of 64KB flash and rich serial connectivity fits firmware-driven control tasks where cost and footprint dominate.
A key design consideration is supply decoupling: place low-ESR ceramic capacitors close to the VDD/VDDIO pins and connect the exposed pad to ground for thermal dissipation and signal integrity.
This page synthesizes distributor availability, drop-in alternatives within the pin-compatible SAM3N/SAM3S families, and practical design notes not found in a single manufacturer datasheet.
Drop-in alternatives for ATSAM3N1BB-MUR 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 ATSAM3N1BB-MUR (same form factor and footprint) β differing in Core Size, Flash Memory, Maximum Clock Frequency, Package, RoHS Status.
Quick Comparison Tool β Select alternative parts for side-by-side comparison:
ATSAM3S1AB-MUR
β Drop-Inβ In Stock
$2.61 / Unit
View Datasheet βATSAM3N1AB-MUR
β Drop-Inπ Reference alternative (not in catalog)
ATSAM3S1AA-MUR
β Drop-In β οΈ εζ°εΎ ιͺθ―π Reference alternative (not in catalog)
ATSAM3N1BB-MUR Maximum Ratings & Electrical Characteristics
| Core Processor | ARM Cortex-M3 |
| Core Size | 32-Bit |
| Maximum Clock Frequency | 48 MHz |
| Flash Memory | 64KB (64K x 8) |
| SRAM | 8KB |
| Supply Voltage Range | 1.62 V to 3.6 V |
| Typical Supply Voltages | 1.8 V / 2.5 V / 3.3 V |
| Connectivity Peripherals | I2C, IrDA, SPI, UART/USART |
| Capacitive Touch | QTouch library support (buttons, wheels, sliders) |
| Package | 64-QFN (9x9 mm) with Exposed Pad |
| Mounting Type | Surface Mount |
| Operating Temperature | -40C to +85C (Industrial) |
| Series | SAM3N |
| Pin Compatibility | Pin-to-pin compatible with SAM3S series and SAM7S64 |
| RoHS Status | Compliant (Green package, MRL B) |
| Packaging Variant | MUR = Tape & Reel |
ATSAM3N1BB-MUR 64-qfn (9x9 mm) with exposed pad Pin Configuration Guide
Pin configuration for ATSAM3N1BB-MUR (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 ATSAM3N1BB-MUR.
Refer to the datasheet for full pin configuration.
Typical Applications
ATSAM3N1BB-MUR is suitable for 6 applications: Industrial Control Boards, Capacitive Touch User Interfaces, Metering and Sensing Nodes, Consumer Appliance Control, Embedded Communication Modules, Portable and Battery-Powered Devices.
Industrial Control Boards
The ATSAM3N1BB-MUR fits industrial control boards where a 48 MHz Cortex-M3 handles sensor polling, actuator sequencing, and fieldbus communication. Its 64KB flash holds control firmware plus a UART/USART or I2C protocol stack, while the 8KB SRAM buffers data frames and state machines. Operating from a standard 3.3V rail across -40C to +85C, it survives factory-floor temperature swings without derating. Because the SAM3N series is pin-to-pin compatible with the SAM3S series, control-board designers keep one PCB layout and can upgrade to SAM3S parts with DMA when throughput demands grow, protecting the layout investment across product generations.
Recommended
Capacitive Touch User Interfaces
Microchip's QTouch library runs directly on the ATSAM3N1BB-MUR, implementing buttons, wheels, and sliders without dedicated touch controllers. The 48 MHz Cortex-M3 performs the charge-transfer sensing and drift compensation in firmware, while 64KB flash holds both the touch library and application logic. The 64-QFN package's low lead inductance supports stable sensor measurements. Typical products include appliance control panels, white-goods HMIs, and small display-less interfaces. Designers should reserve SRAM headroom, since touch acquisition plus debounce filters consume part of the 8KB SRAM budget; the QTouch library's auto-tuning minimizes this overhead versus fixed-threshold implementations.
Recommended
Metering and Sensing Nodes
Smart meters and remote sensing nodes benefit from the ATSAM3N1BB-MUR's 1.62V to 3.6V supply range, which supports direct battery-adjacent operation, and its serial peripherals (UART/USART, I2C, SPI) for reading ADC front-ends and driving communication modems. The 64KB flash accommodates metrology firmware and data logging buffers in the 8KB SRAM. The SAM3N series' aggressive price point, noted by Microchip as pushing its use into cost-sensitive high-volume applications, is central here: meter manufacturers deploy millions of units, so each cent of BOM saving multiplies. The exposed-pad QFN also improves thermal behavior in sealed enclosures.
Recommended
Consumer Appliance Control
Washers, cooktops, and small appliances use the ATSAM3N1BB-MUR to sequence loads, read user inputs, and drive serial-connected display or inverter modules. The 48 MHz Cortex-M3 provides responsive multitasking between touch sensing (QTouch), button polling, and safety interlocks. Its industrial -40C to +85C rating covers unconditioned appliance interiors, and the 1.8V/2.5V/3.3V compatibility eases integration with low-voltage display controllers. RoHS-compliant green packaging (MRL B) meets global consumer-product environmental requirements. Designers value the SAM3N's second-source strategy: pin-compatible SAM3S and SAM7S64 parts offer migration insurance across appliance production cycles lasting many years.
Recommended
Embedded Communication Modules
The ATSAM3N1BB-MUR serves as a protocol bridge in embedded communication modules: its multiple USARTs and SPI ports connect radios, RS-485 transceivers, and host processors, converting between Modbus, custom serial frames, and packet protocols. The 48 MHz core sustains full-duplex UART traffic at high baud rates without dropping bytes, and IrDA support enables infrared links in legacy installations. With 64KB flash, a full protocol stack plus OTA-style firmware update code fits on-chip. The 3.3V-typical operation matches common radio module logic levels, minimizing level-shifting components and PCB area in dense gateway boards.
Recommended
Portable and Battery-Powered Devices
Handheld instruments, portable testers, and battery-powered loggers exploit the ATSAM3N1BB-MUR's 1.62V minimum supply, allowing direct operation from two alkaline cells or a single Li-Ion cell with a simple regulator. The Cortex-M3 architecture supports sleep and wait low-power modes for extending battery life between charges, while the 48 MHz performance delivers responsive user interfaces when awake. The compact 9x9 mm 64-QFN keeps the main controller footprint small on dense portable PCBs. Because firmware is interrupt-driven via the NVIC, the CPU can remain in low-power states between sensor events, waking on USART or timer interrupts to process and transmit readings.
Recommended
Recommended Products Summary
Engineering reference data for ATSAM3N1BB-MUR β comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | ATSAM3S1AB-MUR | ATSAM3N1AB-MUR | ATSAM3S1AA-MUR |
|---|---|---|---|---|
| Package | 64-QFN (9x9) | 64-QFN (9x9) - same footprint | 64-QFN (9x9) - same footprint | 64-QFN (9x9) - same footprint |
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Core / Max Frequency | ARM Cortex-M3, 48 MHz | ARM Cortex-M3, 48 MHz | ARM Cortex-M3, 48 MHz | ARM Cortex-M3, 48 MHz |
| Flash Memory | 64 KB | 64 KB | 32 KB | 32 KB |
| SRAM | 8 KB | 8 KB | 8 KB | 8 KB |
| DMA Controller | No | Yes | No | Yes |
| Supply Voltage Range | 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 |
| Connectivity | I2C, IrDA, SPI, UART/USART | I2C, IrDA, SPI, UART/USART + enhanced peripherals | I2C, IrDA, SPI, UART/USART | I2C, IrDA, SPI, UART/USART + enhanced peripherals |
| Operating Temperature | -40C to +85C | -40C to +85C | -40C to +85C | -40C to +85C |
Key Differentiators
- Lowest cost in the pin-compatible family (vs ATSAM3S1AB-MUR)
- Flash density headroom (vs ATSAM3N1AB-MUR)
- DMA offload for data streaming (vs ATSAM3N1AB-MUR (and ATSAM3N1BB-MUR itself lacks DMA))
Design Notes
Connect the 64-QFN exposed pad to a solid ground plane with an array of thermal vias. The exposed pad is the primary ground return for the die; relying only on perimeter ground pins increases ground bounce on GPIO banks and can corrupt SPI/USART timing at high baud rates. Place 100 nF ceramic decoupling capacitors within 2 mm of each VDD/VDDIO pin pair, plus one bulk 4.7-10 uF capacitor near the supply entry. This follows Microchip's standard SAM3 layout guidance in the SAM3N evaluation-board reference designs.
Do not exceed the 3.6V absolute supply limit - the SAM3N is a low-voltage family, and 5V on any pin will damage the part. When interfacing to 5V legacy peripherals, use level shifters or open-drain configurations with pull-ups to VDD. Also verify flash usage: 64KB appears generous, but a USB-style protocol stack plus touch library can approach the limit; if your firmware exceeds roughly 55KB, plan migration to the pin-compatible SAM3S family with larger memory options early rather than late.
Keep the crystal/oscillator traces short and guarded by ground when using an external crystal, as the QFN perimeter makes adjacent GPIO routing close to clock traces. Route I2C bus with appropriate pull-up sizing (typically 2.2-4.7 kOhm at 3.3V) and avoid long stubs on SPI clock lines. Assign touch sensor pads away from switching regulator nodes when implementing QTouch, since coupled noise raises baseline drift and increases the auto-tuning workload in the QTouch library.
Compliance Information
Mouser and DigiKey listings describe the part as GREEN package, Industrial Temperature, MRL B (Moisture Sensitivity Level indication per Microchip coding). RoHS compliant per Microchip green packaging designation; REACH and conflict-minerals status not stated in provided data.
