ATSAM3S2BA-AUR - Cortex-M3 MCU 64MHz 128KB Flash | Microchip
MPN: ATSAM3S2BA-AUR ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $6.28 | $6.28 |
| 10 | $5.65 | $56.50 |
| 100 | $5.02 | $502.00 |
| 500 | $4.55 | $2,275.00 |
| 1,000 | $4.1 | $4,100.00 |
ATSAM3S2BA-AUR Overview
A microcontroller unit (MCU) is a single integrated circuit that combines a processor core, non-volatile program memory, volatile data memory, and a rich set of peripherals on one die. Within the semiconductor hierarchy, the ATSAM3S2BA-AUR belongs to the Microchip (formerly Atmel) SAM3S family of ARM Cortex-M3 microcontrollers, which sit above simpler 8-bit MCUs in processing capability while retaining low-power operation for embedded control systems.
Key features include the 64 MHz Cortex-M3 core with a 3-stage pipeline and Thumb-2 instruction set, 128 KB of on-chip flash for code storage, fast SRAM, and an extended industrial temperature rating. The peripheral set typical of the SAM3S series includes UART/USART serial ports, SPI, TWI (I2C), an ADC, PWM channels, and USB connectivity, enabling single-chip designs for communication-heavy applications. The device operates from a single 1.62V to 3.6V rail, supporting battery-powered designs.
Architecturally, the ARM Cortex-M3 core integrates a Nested Vectored Interrupt Controller (NVIC) for deterministic low-latency interrupt handling and hardware divide support. Flash-based program memory with in-system programming allows firmware field updates, while the 10x10 mm LQFP-64 package provides sufficient I/O count for display, sensor, and actuator interfaces.
Typical applications include industrial control and automation nodes, consumer appliances, battery-powered portable instruments, and USB-enabled embedded devices where a 32-bit core with ample flash is required without the cost of higher-memory parts.
A key design consideration is supply decoupling: place low-ESR ceramic capacitors close to each VDD/VDDIO pin pair, and confirm 1.8V/3.3V domain separation per the SAM3S datasheet electrical characteristics before PCB routing.
This page synthesizes distributor pricing, drop-in same-family alternatives, cross-reference candidates, and practical design notes not consolidated in the manufacturer datasheet.
Drop-in alternatives for ATSAM3S2BA-AUR — 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 ATSAM3S2BA-AUR (same form factor and footprint) — differing in Core Processor, RoHS Status, Maximum Clock Frequency, Connectivity, DMA.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
ATSAM3S4BA-AUR
✅ Drop-In✓ In Stock
$3.44 / Unit
View Datasheet →ATSAM3S2BA-AU
✅ Drop-In✓ In Stock
$4.66 / Unit
View Datasheet →ATSAM4S2BA-AU
✅ Drop-In✓ In Stock
$3.71 / Unit
View Datasheet →NUC120RE3DN
✅ Drop-In📋 Reference alternative (not in catalog)
ATSAM3S2BA-AUR Maximum Ratings & Electrical Characteristics
| Core Processor | ARM Cortex-M3 |
| Core Size | 32-Bit |
| Maximum Clock Frequency | 64 MHz |
| Flash Memory | 128 KB (128K x 8) |
| SRAM | 32 KB |
| Supply Voltage Range | 1.62 V to 3.6 V |
| Package | 64-LQFP (10x10 mm) |
| Mounting Type | Surface Mount |
| Instruction Set | Thumb-2 |
| Interrupt Controller | NVIC (Nested Vectored Interrupt Controller) |
| Interfaces | UART/USART, SPI, TWI (I2C), USB |
| Peripherals | PWM, ADC, WDT, DMA |
| RoHS Status | Compliant (LQFP, Green) |
| Packaging | Tape & Reel (R suffix) |
ATSAM3S2BA-AUR 64-lqfp (10x10 mm) Pin Configuration Guide
Pin configuration for ATSAM3S2BA-AUR (64-lqfp (10x10 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 ATSAM3S2BA-AUR.
Refer to the datasheet for full pin configuration.
Typical Applications
ATSAM3S2BA-AUR is suitable for 6 applications: Industrial Control and Automation, Battery-Powered Portable Instruments, USB-Enabled Embedded Devices, Consumer Appliances, Building Automation and Sensor Nodes, Medical and Health Monitoring Devices.
Industrial Control and Automation
The ATSAM3S2BA-AUR fits industrial control nodes that need 32-bit processing for protocol handling, deterministic interrupt response via the Cortex-M3 NVIC, and multiple serial links. Its 128 KB flash accommodates Modbus or CAN-adjacent stacks, while UART/USART, SPI, and TWI interfaces connect PLC I/O modules, motor-control front ends, and HMI panels. Running from a 1.62V to 3.6V rail at 64 MHz, the device processes sensor polling loops fast enough to permit aggressive duty cycling. Its industrial temperature capability, indicated by the Mouser 'IND TEMP' listing, supports factory-floor environments where consumer-grade MCUs cannot be specified, and the LQFP-64 I/O count covers multi-sensor boards on a single controller.
Recommended
Battery-Powered Portable Instruments
Handheld meters, data loggers, and portable test instruments benefit from the ATSAM3S2BA-AUR's wide 1.62V to 3.6V supply window, which allows direct operation from a regulated lithium cell or two-cell alkaline stack through a simple LDO. The 64 MHz Cortex-M3 core executes FFT-based measurement math quickly, so the MCU can return to deep-sleep modes within milliseconds of each reading cycle, extending battery life relative to a slower 8-bit device forced into longer active windows. The 128 KB flash retains calibration tables and logged datasets, and the ADC plus PWM peripherals support signal excitation and measurement chains without external mixed-signal ICs, reducing board area in compact handheld enclosures.
Recommended
USB-Enabled Embedded Devices
The SAM3S series integrates USB device connectivity, making the ATSAM3S2BA-AUR a strong fit for USB dongles, PC-connected sensors, and firmware-updatable peripherals. The 64 MHz Cortex-M3 core sustains USB data throughput while simultaneously servicing application tasks, and the 32 KB SRAM buffers endpoint data alongside the application stack. Compared with adding a discrete USB interface chip to a general MCU, the integrated USB reduces bill-of-material cost and PCB routing complexity. The Thumb-2 instruction set keeps bulk-transfer firmware compact within the 128 KB flash, leaving headroom for vendor-specific USB class implementations such as CDC, HID, or mass storage in commercial embedded products.
Recommended
Consumer Appliances
Appliance control boards - coffee machines, air purifiers, kitchen scales, and climate controls - use the ATSAM3S2BA-AUR where capacitive-touch handling, display driving, and motor or heater control converge. The 128 KB flash accommodates UI frameworks and state machines that 8-bit MCUs struggle to fit, while the ADC reads NTC temperature sensors and the PWM channels drive triac-equivalent control or fan speed stages. The green RoHS-compliant LQFP-64 package meets consumer environmental requirements, and the 10x10 mm footprint suits two-layer or four-layer cost-optimized PCBs. The device's 1.62V-3.6V operation simplifies shared-rail designs with off-the-shelf display modules powered from 3.3V.
Recommended
Building Automation and Sensor Nodes
Wall-mounted thermostats, occupancy sensors, and lighting controllers deploy the ATSAM3S2BA-AUR for its combination of TWI (I2C) connectivity to digital sensors, USART links to RS-485 transceivers, and sufficient flash for network protocol firmware. The Cortex-M3's low-latency NVIC handles time-critical bus timing without software polling overhead, and the 1.62V-3.6V input range tolerates widely varying wall-wart rails after basic regulation. The 32 KB SRAM supports buffering for packetized communication, and deep-sleep modes keep standby current low for always-on wall-powered or energy-harvesting nodes. The LQFP-64 pin count provides GPIO headroom for keypad matrices and status LEDs alongside the communication interfaces.
Recommended
Medical and Health Monitoring Devices
Non-invasive health monitors - pulse oximeter accessories, digital thermometers, and activity trackers - leverage the ATSAM3S2BA-AUR's fast 32-bit core to run digital filtering and peak-detection algorithms on ADC-sampled biosignals in real time. The 128 KB flash stores calibration curves and patient data logs, while the 32 KB SRAM provides workspace for DSP-style routines that an 8-bit MCU would execute too slowly. The wide 1.62V-3.6V supply suits single-cell battery designs common in wearables, and the USB interface enables data offload to clinical host PCs without extra chips. Designers should implement the manufacturer's recommended power-supply decoupling to protect sensitive analog front-end measurements from digital switching noise.
Recommended
Recommended Products Summary
Engineering reference data for ATSAM3S2BA-AUR — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | ATSAM3S4BA-AUR | ATSAM3S2BA-AU | ATSAM4S2BA-AU | NUC120RE3DN |
|---|---|---|---|---|---|
| Package | 64-LQFP (10x10 mm) | 64-LQFP (10x10 mm) - same | 64-LQFP (10x10 mm) - same | 64-LQFP - verify footprint | 64-LQFP - different pinout |
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Nuvoton Technology |
| Core | ARM Cortex-M3 | ARM Cortex-M3 | ARM Cortex-M3 | ARM Cortex-M4 | ARM Cortex-M0 |
| Max Clock Frequency | 64 MHz | 64 MHz | 64 MHz | 120 MHz | 50 MHz |
| Flash Memory | 128 KB | 256 KB | 128 KB | 128 KB | 128 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 | 2.5 V to 5.5 V |
| Drop-in Compatibility | - | Yes - pin-to-pin | Yes - identical die | Verify pin mapping | No - redesign required |
Key Differentiators
- Optimal cost-per-KB within SAM3S 64-pin family (vs ATSAM3S4BA-AUR)
- Tape-and-reel delivery for automated assembly (vs ATSAM3S2BA-AU)
- True 32-bit pin-compatible upgrade path within one footprint (vs NUC120RE3DN)
Design Notes
Supply the ATSAM3S2BA-AUR from a clean 1.62V to 3.6V rail, typically a 3.3V LDO output. Decouple each VDD/VDDIO pin pair with 100 nF low-ESR ceramic capacitors placed within a few millimeters of the pin, plus bulk capacitance (10 uF) near the regulator. If USB is used, follow the Microchip SAM3S USB design guidelines for the 3.3V USB transceiver supply domain. Verify the 1.8V/3.3V supply-domain mapping (as noted in FindIC's specification summary) against the datasheet electrical characteristics before routing.
The 64-LQFP 10x10 mm footprint uses 0.5 mm pitch leads; design land patterns per the Microchip package drawing and use solder-mask-defined pads with thermal reliefs on ground connections to reduce tombstoning during reflow. Route the crystal/oscillator traces short and guarded, keep USB differential pairs at 90 ohm matched length, and provide at least one solid ground plane beneath the MCU to control return paths. Place programming/debug header (SWD/JTAG) footprints on production boards for firmware updates.
Do not assume drop-in compatibility across SAM families: the ATSAM4S2BA-AU (Cortex-M4, 120 MHz) shares the 128 KB/64-LQFP profile but pin and peripheral mapping differ from the SAM3S, and the Nuvoton NUC120RE3DN has an entirely different pinout despite matching flash and package. Also distinguish the -AU (tray) and -AUR (tape-and-reel) ordering codes when placing purchase orders; they are electrically identical but arrive in different packaging for different assembly lines.
Compliance Information
DigiKey and Mouser listings describe the part as a Green LQFP package ('LQFP,Green,IND TEMP,MRL A'), indicating RoHS compliance and lead-free finish. REACH, halogen-free, and conflict-minerals status should be confirmed via Microchip's official compliance certificates.