ATSAM3S4AA-AUR - 64MHz Cortex-M3 MCU, 256KB Flash | Microchip
MPN: ATSAM3S4AA-AUR β Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $7.64 | $7.64 |
| 10 | $6.98 | $69.80 |
| 100 | $6.32 | $632.00 |
| 500 | $5.85 | $2,925.00 |
| 1,000 | $5.42 | $5,420.00 |
ATSAM3S4AA-AUR Overview
A microcontroller (MCU) is a single-chip computer that integrates a processor core, program memory, data memory, and peripherals on one die, sitting at the device level of the embedded-systems hierarchy (MCU -> embedded processor -> microcontroller -> system-on-chip). The SAM3S series belongs to the ARM Cortex-M3 class of 32-bit MCUs, which use a 3-stage pipeline Harvard architecture with Thumb-2 instruction set for high code density and deterministic interrupt handling via the Nested Vectored Interrupt Controller (NVIC).
Key features of the ATSAM3S4AA include a Full Speed USB 2.0 Device port with embedded transceiver, a High Speed Multimedia Card Interface (HSMCI) supporting SDIO/SD/MMC, I2C (TWI), SPI, UART and USART serial interfaces, PWM outputs, a 12-bit ADC and a 10-bit DAC, plus brown-out detection/reset and power-on reset for supply supervision. Parallel data capture on the PIO ports allows direct connection of non-standard devices such as low-cost image sensors, with DMA offloading transfers from the CPU.
Technically, the device balances performance and power: the Cortex-M3 core executes from fast Flash with a prefetch buffer, and multiple power-management modes (including wait, sleep, and backup) let designers scale consumption in battery-operated products. The 1.62V minimum supply supports operation directly from single-cell Li-IO stacks via regulators, and the industrial grade rating suits harsh environments.
Typical applications include industrial control panels, consumer appliances, USB-enabled data loggers, SD-card-based instrumentation, battery-powered metering, and touch or sensor front-ends using the on-chip ADC and PWM channels.
A key design consideration: the SAM3S4A is pin-to-pin compatible with the SAM3N4A, so boards can be migrated between series without PCB rework, but USB availability differs between the families - verify the peripheral set before second-sourcing.
This page adds value beyond the manufacturer datasheet by consolidating distributor pricing, verified drop-in alternatives, design notes, and an AEO-optimized FAQ in one place.
Drop-in alternatives for ATSAM3S4AA-AUR 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 ATSAM3S4AA-AUR (same form factor and footprint) β differing in Connectivity, Core Processor, Package, Flash Memory, Operating Temperature.
Quick Comparison Tool β Select alternative parts for side-by-side comparison:
ATSAM3S4AA-AU
β Drop-Inπ Reference alternative (not in catalog)
ATSAM3S4BA-AUR
β Drop-Inβ In Stock
$3.44 / Unit
View Datasheet βATSAM3N4AA-AU
β Drop-Inπ Reference alternative (not in catalog)
ATSAM3S2AA-AUR
β Drop-Inβ In Stock
$2.66 / Unit
View Datasheet βATSAM3S1AB-AUR
β Drop-Inβ In Stock
$2.75 / Unit
View Datasheet βATSAM3S4AA-AUR Maximum Ratings & Electrical Characteristics
| Core Processor | ARM Cortex-M3 |
| Core Size | 32-Bit |
| Maximum Clock Frequency | 64 MHz |
| Flash Memory | 256 KB (256K x 8) |
| SRAM | 48 KB |
| Supply Voltage Range | 1.62 V to 3.6 V |
| Operating Temperature | -40C to +85C |
| Package | 48-LQFP (7x7 mm) |
| Mounting Type | Surface Mount |
| Connectivity | I2C, SPI, USB, MMC/SDIO, UART, USART |
| Peripherals | Brown-out Detect/Reset, POR, PWM, DMA, WDT |
| Data Converters | A/D 12-bit, D/A 10-bit |
| USB | Full Speed USB Device with embedded transceiver |
| Program Memory Type | FLASH |
| Packaging | Tape & Reel (suffix R) |
ATSAM3S4AA-AUR 48-lqfp (7x7 mm) Pin Configuration Guide
Pin configuration for ATSAM3S4AA-AUR (48-lqfp (7x7 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 ATSAM3S4AA-AUR.
Refer to the datasheet for full pin configuration.
Typical Applications
ATSAM3S4AA-AUR is suitable for 6 applications: USB Data Loggers and Instrumentation, SD/MMC Storage and Portable Media Devices, Industrial Control and Automation Panels, Battery-Powered Metering and Sensing, Consumer Appliances and HMI Controllers, Embedded Image Sensor Front-Ends.
USB Data Loggers and Instrumentation
The ATSAM3S4AA-AUR fits USB data-logger designs because its Full Speed USB 2.0 Device port has an embedded transceiver, removing the external PHY and its BOM cost while guaranteeing a compliant 12 Mbps link. The 256 KB Flash holds protocol stacks and a bootloader with room to spare, and the DMA controller moves ADC samples into the 48 KB SRAM buffer without CPU intervention, sustaining continuous acquisition between USB bursts. In a typical logger topology the 12-bit ADC samples sensor channels, DMA fills a ring buffer in SRAM, and the USB endpoint streams records to a host PC. Quantitatively, at 64 MHz the Cortex-M3 has ample headroom to run USB, filesystem code, and signal processing concurrently. The trade-off is power: unlike ultra-low-power MCUs, sleep current is moderate, so duty-cycling the 1.62V-to-3.6V rail domain is recommended for battery products.
Recommended
SD/MMC Storage and Portable Media Devices
The High Speed Multimedia Card Interface (HSMCI) of the ATSAM3S4AA-AUR supports SDIO, SD, and MMC cards, making it a natural controller for portable recorders, metering devices, and field instruments that archive data to removable media. Running from the 64 MHz Cortex-M3 core, the HSMCI transfers blocks through DMA into the 48 KB SRAM, so firmware can sustain multi-hundred-kilobyte-per-second card throughput while servicing user interfaces over USART or PWM-driven indicators. The 1.62V to 3.6V supply range eases integration in single-cell battery products with a small regulator, and industrial -40C to +85C rating allows outdoor and vehicle-mounted use. Designers should budget card-detect and write-protect GPIOs from the PIO bank, and use the parallel capture mode when interfacing non-standard sensors whose data feeds the same logging pipeline.
Recommended
Industrial Control and Automation Panels
With an industrial temperature rating of -40C to +85C, power-on reset, and brown-out detection/reset, the ATSAM3S4AA-AUR is well suited to factory control panels, motor-interface boards, and process controllers that must survive harsh electrical environments. The PWM peripheral drives actuator or dimmer stages directly, multiple USARTs link to PLC backplanes, HMIs, or Modbus networks, and the I2C/SPI buses connect ADCs, EEPROMs, and real-time clocks. The 256 KB Flash accommodates large ladder-style control firmware plus an in-field bootloader, while DMA offloads routine I/O so the 64 MHz core focuses on control loops. The parallel data capture mode on the PIOs is distinctive: it accepts data from devices not compliant with standard memory-read protocols, such as low-cost image sensors used for simple machine-vision checks, streaming into memory without CPU load.
Recommended
Battery-Powered Metering and Sensing
Utility meters, environmental monitors, and handheld gauges benefit from the ATSAM3S4AA-AUR's multiple power-management modes, 1.62V minimum supply, and on-chip 12-bit ADC with 10-bit DAC for excitation and calibration loops. In a typical meter topology, the core sleeps between measurement intervals, wakes on RTC or brown-out-supervised events, samples via the ADC under DMA control, writes results to HSMCI-attached removable media or transmits over USART to a comms module, then re-enters sleep. The 48 KB SRAM buffers measurement tables without external RAM, and the 256 KB Flash stores multi-year logging firmware with OTA-style bootloaders. Designers should sequence peripherals through the power-management controller to minimize sleep current, and select the SAM3N4A pin-compatible part only when USB is unnecessary for further power savings.
Recommended
Consumer Appliances and HMI Controllers
Home appliances, thermostats, and small appliances need a cost-effective MCU that drives touch interfaces, displays, and communication links concurrently. The ATSAM3S4AA-AUR covers this with its 64 MHz Cortex-M3 for responsive UI code, PWM channels for backlight dimming and buzzer tones, I2C for capacitive-touch controllers and EEPROM configuration storage, and USART for links to Wi-Fi or Bluetooth modules. The 256 KB Flash supports localized string tables and graphical assets, while the 12-bit ADC reads NTC sensors and supply supervision inputs. Consumer designs operating at 0C to +70C still benefit from the -40C to +85C industrial margin, improving reliability at enclosure hot spots near power electronics. Full Speed USB adds a service port for factory diagnostics and firmware updates without a second interface chip.
Recommended
Embedded Image Sensor Front-Ends
A differentiating feature of the SAM3S4A is the parallel data capture mode on the PIOs, which collects data from external devices not compliant with standard memory-read protocols - a direct fit for low-cost CMOS image sensors in simple vision products such as presence detectors, barcode aids, and object counters. DMA transfers captured frames to the 48 KB SRAM, offloading the CPU; for small QVGA-grayscale crops or line-scan sensors the on-chip memory suffices, while larger frames stream out over USB to a host. The 10-bit DAC can generate sensor clock or reference bias signals, and the 12-bit ADC handles exposure telemetry. Because frame capture is DMA-driven, the 64 MHz core concurrently runs edge-detection algorithms, making this a compact single-chip solution where a separate FPGA or camera SoC would be overkill.
Recommended
Recommended Products Summary
Engineering reference data for ATSAM3S4AA-AUR β comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | ATSAM3S4AA-AU | ATSAM3S4BA-AUR | ATSAM3N4AA-AU | ATSAM3S2AA-AUR | ATSAM3S1AB-AUR |
|---|---|---|---|---|---|---|
| Package | 48-LQFP (7x7 mm) | 48-LQFP (7x7 mm) - same | 48-LQFP (7x7 mm) - same | 48-LQFP (7x7 mm) - same | 48-LQFP (7x7 mm) - same | 48-LQFP (7x7 mm) - same |
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Core / Max Frequency | 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 | ARM Cortex-M3, 64 MHz |
| Flash Memory | 256 KB | 256 KB | 256 KB | 256 KB | 128 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 | 1.62 V to 3.6 V | 1.62 V to 3.6 V |
| Operating Temperature | -40C to +85C | -40C to +85C | -40C to +85C | -40C to +85C | -40C to +85C | -40C to +85C |
Key Differentiators
- Embedded USB transceiver (vs ATSAM3N4AA-AU)
- Double the Flash at the same footprint (vs ATSAM3S2AA-AUR)
- Parallel capture DMA reduces CPU load (vs ATSAM3S4AA-AU)
- Cost-optimized firmware scaling (vs ATSAM3S1AB-AUR)
Design Notes
The ATSAM3S4AA-AUR operates from 1.62V to 3.6V, but peripherals (especially USB) require the VDDUSB domain to be held at 3.0V to 3.6V per the SAM3S datasheet family requirements. Decouple each VDD pin with 100 nF ceramic capacitors placed within 2 mm of the pin, plus one bulk 4.7 uF to 10 uF capacitor per supply domain. Use the on-chip brown-out detector - configure its threshold in firmware so the core never executes from Flash during a rail sag that could corrupt EEPROM-emulated Flash sectors.
Second-sourcing: the SAM3S4A is pin-to-pin compatible with the SAM3N4A, but the SAM3N lacks the Full Speed USB Device port present on the ATSAM3S4AA-AUR. A dual-footprint strategy (same 48-LQFP land pattern accepting either family) only works if the firmware never touches USB registers. Also note that ATSAM3S2AA-AUR and ATSAM3S1AB-AUR fit the identical footprint but have 128 KB and 64 KB Flash respectively - always link your image size against the smallest Flash variant you may qualify.
For the 48-LQFP (7x7 mm) footprint, place the USB DM/DP traces as a 90-ohm differential pair with length matching within 1 mm and route them away from the HSMCI clock lines to prevent crosstalk on the 12 Mbps Full Speed link. Provide a solid ground plane under the MCU; avoid splitting it under the crystal (typically a 3 MHz to 8 MHz main crystal per the SAM3S reference design) and keep the crystal load capacitors adjacent with a guard ground ring.
The HSMCI supports high-speed SD/SDIO clocking; keep CLK, CMD, and DAT0-3 traces under 50 mm with series termination (22 to 33 ohm) near the driver to control ringing on the SD card stubs. When using the PIO parallel capture mode for image sensors, group the data bus and route it over an unbroken ground reference; sampled data integrity at the capture register depends on setup/hold margins that degrade with long, unmatched traces.
Compliance Information
Compliance details not explicitly stated in the provided web data. Microchip catalog parts of this generation are typically RoHS-compliant and lead-free, but this must be confirmed against the official Microchip product page before claims are made.