ATSAM3N1BB-MU - 48MHz Cortex-M3 MCU 64KB Flash | Microchip
MPN: ATSAM3N1BB-MU β Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $4.62 | $4.62 |
| 10 | $4.16 | $41.60 |
| 100 | $3.68 | $368.00 |
| 500 | $3.31 | $1,655.00 |
| 1,000 | $2.95 | $2,950.00 |
ATSAM3N1BB-MU Overview
A microcontroller (MCU) is a single-chip embedded processor that integrates a CPU core, program memory, data memory, and peripherals such as UARTs, SPI, I2C, timers, and ADCs. Within the power-management hierarchy of embedded systems, the MCUs sit at the application-control layer, executing firmware that orchestrates sensors, actuators, and communication interfaces. The SAM3N series belongs to Microchip's (formerly Atmel) ARM-based flash MCU family, positioned for cost-sensitive, high-volume industrial and consumer designs.
Key features of the ATSAM3N1BB 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). Embedded Flash uses a 128-bit wide access bus with a memory accelerator to sustain zero-wait-state execution at 48 MHz. The device supports Microchip's QTouch library for capacitive touch buttons, wheels, and sliders, adding touch interfaces without external controllers.
Architecturally, the SAM3N1B emphasizes integration and legacy compatibility: it is pin-to-pin compatible with the SAM7S legacy products (48- and 64-pin versions) and with the SAM3S series (48-, 64-, and 100-pin versions), which protects existing PCB investments during platform migrations. The 64-QFN package exposes a bottom pad that must be connected to ground per the datasheet, providing both electrical grounding and thermal relief.
Typical applications include industrial control nodes, consumer appliances, capacitive-touch user interfaces, and general-purpose embedded controllers where 64 KB of Flash and 48 MHz performance suffice at an aggressive price point.
A key design consideration is supply supervision: operating from 1.62V to 3.6V, the part tolerates 1.8V, 2.5V, and 3.3V rails, but brown-out configuration and decoupling should follow the manufacturer datasheet for reliable Flash operation.
This page synthesizes distributor pricing, drop-in alternatives, pin-compatibility cross-references, and practical design notes not found in the manufacturer datasheet.
Drop-in alternatives for ATSAM3N1BB-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 ATSAM3N1BB-MU (same form factor and footprint) β differing in Core Processor, SRAM.
Quick Comparison Tool β Select alternative parts for side-by-side comparison:
ATSAM3N1BA-MU
β Drop-Inπ Reference alternative (not in catalog)
ATSAM3S1BA-MU
β Drop-In β οΈ εζ°εΎ ιͺθ―β In Stock
$1.53 / Unit
View Datasheet βATSAM3N1BB-MU Maximum Ratings & Electrical Characteristics
| Core Processor | ARM Cortex-M3 revision 2.0 |
| Core Size | 32-bit |
| Maximum Clock Frequency | 48 MHz |
| Flash Memory | 64 KB (64K x 8) |
| SRAM | 8 KB |
| Supply Voltage Range | 1.62 V to 3.6 V |
| Supply Voltage Nominal | 1.8 V / 2.5 V / 3 V / 3.3 V |
| Instruction Set | Thumb-2 |
| SysTick Counter | 24-bit |
| Interrupt Controller | Nested Vector Interrupt Controller (NVIC) |
| Capacitive Touch | QTouch library support |
| Package | 64-QFN (9x9 mm) |
| Mounting Type | Surface Mount |
| Temperature Grade | Industrial |
| Operating Temperature | -40C to +85C |
| Pin Compatibility | Pin-to-pin compatible with SAM7S (48/64-pin) and SAM3S (48/64/100-pin) |
| QFN Bottom Pad | Must be connected to ground (per datasheet) |
| RoHS Status | Compliant (QFN, Grn per Mouser) |
ATSAM3N1BB-MU 64-qfn (9x9 mm) Pin Configuration Guide
Pin configuration for ATSAM3N1BB-MU (64-qfn (9x9 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 ATSAM3N1BB-MU.
Refer to the datasheet for full pin configuration.
Typical Applications
ATSAM3N1BB-MU is suitable for 6 applications: Industrial Control Nodes, Capacitive Touch User Interfaces, Cost-Sensitive Consumer Appliances, Legacy SAM7S Design Migration, Sensor Acquisition and Data Loggers, Motor Control and Power Accessories.
Industrial Control Nodes
The ATSAM3N1BB-MU fits industrial control and monitoring nodes where 48 MHz Cortex-M3 performance, 64 KB Flash, and industrial -40C to +85C temperature rating are sufficient. Its rich peripheral set (UART, SPI, TWI/I2C, timers, ADC) interfaces with sensors, actuators, and Modbus-style RS-485 links through external transceivers. Running deterministic firmware with the NVIC providing low-latency interrupts, it handles real-time polling and control loops reliably. Because the SAM3N series is pin-to-pin compatible with SAM3S, designers can later migrate to a USB-capable variant on the same PCB if fieldbus requirements expand, protecting the PCB investment across product generations.
Recommended
Capacitive Touch User Interfaces
Per the Microchip product page, the SAM3N1B is 'ready for capacitive touch thanks to the Microchip QTouch library', enabling buttons, wheels, and sliders without a dedicated touch controller. The 48 MHz Cortex-M3 core has adequate headroom to run charge-transfer acquisition plus the main application concurrently. With 64 KB Flash, the QTouch library and application code coexist comfortably. Typical deployments include appliance control panels, white-goods interfaces, and HVAC thermostats, where the 1.62V to 3.6V supply range simplifies power design from a single 3.3V rail and the 64-QFN 9x9 mm package provides sufficient GPIO count for both touch channels and display or relay drive.
Recommended
Cost-Sensitive Consumer Appliances
Microchip positions the SAM3N series at 'an aggressive price point' that 'pushes its scope of use far into cost-sensitive, high-volume applications'. The ATSAM3N1BB-MU with 64 KB Flash suits coffee machines, small kitchen appliances, personal-care devices, and toy electronics that need 32-bit processing but not USB or large memory. The single-supply 1.8V/3.3V operation, integrated brown-out and watchdog functions reduce external component count, cutting BOM cost. The 64-QFN (9x9 mm) leadless package also supports compact, low-profile product enclosures, and its green/RoHS packaging satisfies global consumer-environmental regulations without additional compliance engineering.
Recommended
Legacy SAM7S Design Migration
The datasheet documents that SAM3N devices are 'pin-to-pin compatible with SAM7S legacy products (48- and 64-pin versions)', making the ATSAM3N1BB-MU the designated upgrade path for aging SAM7S64-based boards. The modern Cortex-M3 revision 2.0 core with Thumb-2 instructions and 128-bit wide Flash access with memory accelerator delivers substantially higher effective throughput than the ARM7TDMI at the same 48 MHz clock. Firmware porting effort is moderate because peripheral concepts map between families and Microchip provides migration application notes. The same 64-pin footprint means no PCB respin, so products gain performance and continued silicon supply without hardware redesign risk.
Recommended
Sensor Acquisition and Data Loggers
With its on-chip ADC, multiple USART/SPI/TWI interfaces, 8 KB SRAM, and 64 KB Flash, the ATSAM3N1BB-MU serves as the acquisition engine in data loggers, environmental monitors, and metering front-ends. The 24-bit SysTick timer and NVIC support time-stamped sampling, while DMA-style peripheral handshaking in the SAM3N bus matrix keeps CPU load low during transfers. The 1.62V to 3.6V supply range allows direct operation from lithium primary cells through a small LDO, extending battery life in unattended installations. Industrial temperature rating (-40C to +85C) ensures reliable logging in outdoor enclosures, cold-chain equipment, and factory-floor environments without derating.
Recommended
Motor Control and Power Accessories
The 48 MHz Cortex-M3 core with fast NVIC interrupt response can service PWM update and current-loop interrupts for small DC and BLDC motor drives in fans, pumps, and small appliances. On-chip PWM-capable timers generate complementary gate signals to external MOSFET drivers, while the ADC samples shunt current and bus voltage. The 64 KB Flash accommodates commutation tables, PI control, and protection state machines. Designers must ground the QFN bottom pad per the datasheet, which also improves thermal behavior in the thermally active motor-drive environment. Pin compatibility with SAM3S preserves a path to more timer-rich variants if control complexity grows.
Recommended
Recommended Products Summary
Engineering reference data for ATSAM3N1BB-MU β comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | ATSAM3N1BA-MU | ATSAM3S1BA-MU | ATSAM3S1BB-AU | ATSAM7S64D-AU |
|---|---|---|---|---|---|
| Package | 64-QFN (9x9 mm) | 64-QFN (9x9 mm) - same | 64-QFN (9x9 mm) - same | LQFP-64 | LQFP-64 |
| Brand | Microchip Technology (Atmel) | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology (Atmel) |
| Core / Clock | ARM Cortex-M3, 48 MHz | ARM Cortex-M3, 48 MHz | ARM Cortex-M3, 48 MHz | ARM Cortex-M3, 48 MHz | ARM7TDMI, 55 MHz |
| Flash Memory | 64 KB | 48 KB | 48 KB | 64 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 | 1.8 V to 3.6 V |
| USB Peripheral | No | No | Yes (USB 2.0 device) | Yes (USB 2.0 device) | Yes (USB 2.0 device) |
| Pin Compatibility | SAM7S 64-pin / SAM3S 64-pin compatible | Same SAM3N family - compatible | Pin-to-pin with SAM3N (per datasheet) | Pin-compatible function, LQFP-64 footprint | Pin-to-pin function with SAM3N 64-pin |
| Lifecycle Status | Active | Active | Active | Active | Legacy / mature |
Key Differentiators
- 64 KB Flash at aggressive cost point (vs ATSAM3N1BA-MU)
- Lowest-cost option without USB overhead (vs ATSAM3S1BB-AU)
- Modern Cortex-M3 with memory accelerator (vs ATSAM7S64D-AU)
Design Notes
Ground the QFN bottom pad. The SAM3N datasheet explicitly states: 'The bottom pad of the QFN package must be connected to ground.' Design the 64-QFN (9x9 mm) land pattern with the center pad tied to the ground plane through a 3x3 or larger via array. Beyond meeting the electrical requirement, this via array provides the primary heat-removal path for the die. Skipping this connection is a common root cause of erratic reset and ADC-noise issues on SAM3N boards.
The ATSAM3N1BB-MU operates from 1.62V to 3.6V, accommodating 1.8V, 2.5V, 3.0V, and 3.3V rails. Place 100 nF ceramic decoupling capacitors at each supply pin pair plus one bulk capacitor (4.7 uF to 10 uF) near the device, following the reference power distribution in the SAM3N datasheet. Configure the on-chip brown-out detector for the chosen rail so Flash programming margins are respected during supply dips; verify VDDCORE sequencing requirements against the datasheet power-supply section before finalizing the regulator design.
Do not assume migration is code-identical when moving between SAM3N, SAM3S, and SAM7S: although they are pin-to-pin compatible, peripheral register maps and clock tree differ across families. Flash erase/program timing and the memory accelerator behavior also differ. Budget firmware porting time, use Microchip's migration application notes, and validate on an SAM3N evaluation kit before committing production firmware. For touch designs, reserve GPIO and routing per the QTouch library channel guidelines early in layout.
Keep the clock source (internal RC or external crystal circuit) traces short and guarded with ground, since the 48 MHz system clock and its harmonics can couple into analog peripherals. Route ADC inputs away from switching signals and provide an RC anti-alias filter matched to the datasheet ADC input impedance. For boards using the SAM3N/SAM7S pin-compatibility for drop-in migration, confirm that nets repurposed for new SAM3N-specific functions (italic-marked pins in datasheet Table 4-3) are compatible with legacy board connections.
Compliance Information
Mouser lists the part as 'QFN, Grn, IT, MRL B' - Grn indicates green (RoHS/halogen-free) packaging and IT indicates industrial temperature grade. Formal REACH and conflict-minerals declarations should be obtained from Microchip.
