ATSAM3S2AA-MU - 64MHz Cortex-M3 MCU 128KB Flash | Microchip
MPN: ATSAM3S2AA-MU β Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $5.59 | $5.59 |
| 10 | $5.1 | $51.00 |
| 100 | $4.55 | $455.00 |
| 500 | $4.05 | $2,025.00 |
| 1,000 | $3.6 | $3,600.00 |
ATSAM3S2AA-MU Overview
A microcontroller unit (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: microcontroller -> embedded processor -> system-on-chip. The SAM3S series belongs to Atmel (now Microchip) ARM-based flash MCU family and sits above 8-bit AVR and PIC16 parts in performance while retaining low power operation.
Key features include the ARM Cortex-M3 revision 2.0 core with Memory Protection Unit (MPU) and Thumb-2 instruction set, a 128-bit-wide flash accelerator for zero-wait-state execution at full speed, USB 2.0 Full-Speed device port, and a rich peripheral set including a 12-bit ADC, 2-channel 16-bit PWM, USARTs, and a parallel capture mode on the PIOs for low-cost image sensors.
The device operates from a 1.62V to 3.6V supply (1.8V/3.3V nominal rails), making it compatible with both Li-ion battery and standard 3.3V industrial power domains. DMA is available on all major peripherals, offloading data movement from the CPU and reducing active current consumption. The part is pin-to-pin compatible with the AT91SAM7S legacy family and the SAM3N series, enabling straightforward platform upgrades.
Typical applications include industrial sensors and HMI panels, consumer appliances, battery-powered portable instruments, and USB-connected data acquisition devices where 64 MHz performance and USB connectivity are required without the cost of larger MCUs.
Design consideration: minimize power by using the Flash Living Region and Sleep/Wait/BackUp modes; use wait-state-free code placement carefully as performance depends on the flash accelerator behavior.
This page synthesizes verified distributor pricing, drop-in alternatives, and practical design notes not found in the manufacturer datasheet.
Drop-in alternatives for ATSAM3S2AA-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 ATSAM3S2AA-MU (same form factor and footprint) β differing in Flash Memory, SRAM, Core Processor, Package, Series.
Quick Comparison Tool β Select alternative parts for side-by-side comparison:
ATSAM3S4AA-MU
β Drop-In β οΈ εζ°εΎ ιͺθ―β In Stock
$3.85 / Unit
View Datasheet βATSAM3S1AA-MU
β Drop-In β οΈ εζ°εΎ ιͺθ―β In Stock
$3.34 / Unit
View Datasheet βATSAM3N1AA-MU
β Drop-Inβ In Stock
$3.18 / Unit
View Datasheet βATSAM3N4BA-MU
β Drop-Inβ In Stock
$3.48 / Unit
View Datasheet βATSAM4LC4AA-MU
β Drop-In β οΈ εζ°εΎ ιͺθ―β In Stock
$4.45 / Unit
View Datasheet βATSAM3S2AA-MU Maximum Ratings & Electrical Characteristics
| Core Processor | ARM Cortex-M3 (revision 2.0) |
| Core Size | 32-bit |
| Max Clock Speed | 64 MHz |
| Flash Memory | 128 KB (128K x 8) |
| SRAM | 32 KB |
| Supply Voltage Range | 1.62 V to 3.6 V |
| Supply Voltage Nominal | 1.8 V / 3.3 V |
| I/O Count | 47 I/O ports |
| Package | 48-QFN (7x7 mm) exposed pad |
| Mounting Type | Surface Mount |
| Instruction Set | Thumb-2 |
| Memory Protection | MPU included |
| USB | USB 2.0 Full-Speed device |
| Pin Compatibility | Pin-to-pin compatible with AT91SAM7S and SAM3N (48-pin) |
| Life Cycle Stage | Active |
| Peripherals | DMA, 12-bit ADC, PWM, USART, parallel capture PIO |
ATSAM3S2AA-MU 48-qfn (7x7 mm) exposed pad Pin Configuration Guide
Pin configuration for ATSAM3S2AA-MU (48-qfn (7x7 mm) 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 ATSAM3S2AA-MU.
Refer to the datasheet for full pin configuration.
Typical Applications
ATSAM3S2AA-MU is suitable for 6 applications: Industrial Sensor Nodes, USB Data Acquisition Devices, Battery-Powered Portable Instruments, Consumer Appliance Control Boards, Low-Cost Image Sensor Interface, Legacy AT91SAM7S Platform Upgrades.
Industrial Sensor Nodes
The ATSAM3S2AA-MU fits industrial sensor nodes where a 64 MHz Cortex-M3 processes filtering and protocol stacks while a 12-bit ADC digitizes transducer signals. The wide 1.62V to 3.6V supply range tolerates unregulated industrial rails, and DMA on USARTs and the ADC keeps CPU load low during continuous sampling. With 128 KB flash, both application code and a Modbus or CAN-style communication stack fit comfortably. Sleep and Wait modes reduce standby current for battery-backed nodes, and the parallel capture PIO mode can ingest parallel-output sensors directly without external logic, per the Microchip product description.
Recommended
USB Data Acquisition Devices
The integrated USB 2.0 Full-Speed device controller with dedicated DMA makes the ATSAM3S2AA-MU a strong fit for USB-connected DAQ sticks and instruments. Sample data streams from the 12-bit ADC through DMA into SRAM and out over USB bulk endpoints without CPU intervention, sustaining near-maximum Full-Speed throughput at 12 Mbps. The 32 KB SRAM buffers bursts, while the 64 MHz core handles host command parsing and calibration math. Because the SAM3N alternatives lack USB, designs requiring host connectivity should stay within the SAM3S family; the same 48-QFN footprint allows flash-size migration as firmware grows.
Recommended
Battery-Powered Portable Instruments
For handheld meters and portable instruments, the ATSAM3S2AA-MU operates directly from a Li-ion cell across its full 1.62V to 3.6V range, eliminating a dedicated regulator near end-of-discharge. Multiple low-power modes (Sleep, Wait, BackUp) plus peripheral DMA let the CPU stay idle between measurements; the datasheet family description emphasizes low-power operation at 64 MHz. The 12-bit ADC reads sensor front-ends, PWM drives backlight or haptic outputs, and 128 KB flash holds GUI firmware and calibration tables. Pin compatibility with AT91SAM7S allows reuse of proven handheld PCB layouts during platform upgrades.
Recommended
Consumer Appliance Control Boards
Appliance control boards use the ATSAM3S2AA-MU for motor PWM, user-interface scanning, and USB service ports. The 2-channel 16-bit PWM with 64 MHz resolution controls fans, pumps, or dimmers, while 47 GPIO handle relays, encoders, and segment displays. DMA-driven USARTs manage external EEPROM or display bridges, and the parallel capture mode reads low-cost touch or sensor arrays, as described on the Microchip product page. The industrial temperature availability noted by Mouser supports kitchen and HVAC environments, and the 48-QFN exposed pad gives a robust ground plane for EMI-heavy appliance enclosures.
Recommended
Low-Cost Image Sensor Interface
The SAM3S parallel data capture mode on the PIOs collects data from external devices not compliant with standard memory read protocols, such as low-cost image sensors, according to the Microchip product description. DMA transfers the captured frames to the 32 KB SRAM, offloading the CPU, which then performs cropping, thresholding, or JPEG-free compression before forwarding data over USB or USART. The 64 MHz Cortex-M3 delivers enough headroom for simple machine-vision tasks in entry-level security cameras, presence detectors, and barcode readers where a full ISP or application processor is unnecessary and cost is critical.
Recommended
Legacy AT91SAM7S Platform Upgrades
Designers maintaining AT91SAM7S-based products can drop the ATSAM3S2AA-MU onto the same PCB footprint: the Atmel datasheet explicitly states pin-to-pin compatibility with AT91SAM7S legacy products in 48- and 64-pin versions. The upgrade roughly doubles compute (64 MHz vs 55 MHz), adds DMA to peripherals, improves the flash accelerator, and introduces USB where the SAM7S lacked it in smaller variants. Firmware migrates with recompilation under updated CMSIS/ASF toolchains. This path extends product lifecycles for installed industrial and medical accessories without requalifying the PCB, connectors, or power tree.
Recommended
Recommended Products Summary
Engineering reference data for ATSAM3S2AA-MU β comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | ATSAM3S4AA-MU | ATSAM3S1AA-MU | ATSAM3N1AA-MU | ATSAM3N4BA-MU |
|---|---|---|---|---|---|
| Package | 48-QFN (7x7 mm) exposed pad | 48-QFN (7x7 mm) - same | 48-QFN (7x7 mm) - same | 48-QFN (7x7 mm) - same | 48-QFN (7x7 mm) - same |
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Core / Max Speed | ARM Cortex-M3 / 64 MHz | ARM Cortex-M3 / 64 MHz | ARM Cortex-M3 / 64 MHz | ARM Cortex-M3 / 64 MHz | ARM Cortex-M3 / 64 MHz |
| Flash Memory | 128 KB | 256 KB | 64 KB | 80 KB | 256 KB |
| USB Controller | USB 2.0 Full-Speed device | USB 2.0 Full-Speed device | USB 2.0 Full-Speed device | None | None |
| 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 |
| Pin Compatibility | SAM3S/SAM3N/AT91SAM7S 48-pin | Yes - pin-to-pin | Yes - pin-to-pin | Yes - per datasheet | Yes - per Microchip |
Key Differentiators
- Integrated USB 2.0 Full-Speed device controller (vs ATSAM3N4BA-MU)
- Mid-range memory balancing cost and headroom (vs ATSAM3S4AA-MU)
- Legacy AT91SAM7S pin compatibility (vs ATSAM3S1AA-MU)
- Trade-off: lower compute than SAM4L (vs ATSAM4LC4AA-MU)
Design Notes
Estimated: at 3.3V nominal supply and typical active current in the low-tens-of-mA range for a 64 MHz Cortex-M3 class device, power dissipation remains well under 150 mW, so the 48-QFN exposed pad needs no heatsink; instead, solder the exposed pad to a ground pour for low-impedance return and EMI control. The 1.62V to 3.6V range allows direct Li-ion connection, but add bulk decoupling (10 uF + 0.1 uF) at VDDIO/VDDCORE pins and follow the datasheet power-supply sequencing guidance for dual-rail startup.
Place 0.1 uF ceramic decouplers within 2 mm of each supply pin and the 10 uF bulk cap nearby. Solder the exposed pad to a stitched ground plane array - this is both the electrical ground and the thermal path. Keep the USB D+/D- pair routed as 90-ohm differential with length matching; the SAM3S datasheet USB section specifies Full-Speed signaling requirements. Provide a 1.8V core supply only if the external-regulator variant of the power scheme is used; otherwise the internal regulator needs its specified output capacitor.
Do not substitute pin-compatible SAM3N parts (ATSAM3N1AA-MU, ATSAM3N4BA-MU) into designs that use USB - the SAM3N series has no USB controller and firmware will fail at enumeration. Verify flash size before migrating between ATSAM3S1AA (64 KB), ATSAM3S2AA (128 KB), and ATSAM3S4AA (256 KB): the linker map must fit the target with margin for future OTA or feature growth. When migrating from AT91SAM7S, recompile with the SAM3S device header set; register maps differ even though the footprint matches.
Use the DMA channels for ADC and USART traffic rather than interrupt-driven byte moves - this both frees the 64 MHz CPU and reduces jitter in the analog sampling path. Keep the analog reference and ADC input traces away from USB and oscillator lines; use the parallel capture PIO mode for non-standard parallel sensors as described in the Microchip product documentation, and terminate long parallel capture lines to control ringing.
Compliance Information
Verified web data does not explicitly state RoHS/REACH status; confirm via Microchip product page compliance section or material declaration before use in regulated products.
