ATSAM3S1AA-MU - Cortex-M3 64MHz MCU 64KB Flash | Microchip
MPN: ATSAM3S1AA-MU ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $5.12 | $5.12 |
| 10 | $4.61 | $46.10 |
| 100 | $4.12 | $412.00 |
| 500 | $3.71 | $1,855.00 |
| 1,000 | $3.34 | $3,340.00 |
ATSAM3S1AA-MU Overview
A microcontroller (MCU) is a single-chip computer integrating a processor core, non-volatile program memory, SRAM data memory, and peripherals such as UARTs, timers, and USB. The ATSAM3S1AA-MU belongs to the 32-bit microcontroller class, sitting within the ARM Cortex-M family hierarchy under the SAM3S product series, and is designed as an upgrade path from Atmel's legacy AT91SAM7S family.
Key features include the ARM Cortex-M3 revision 2.0 core with a Thumb-2 instruction set and Memory Protection Unit (MPU), a Full Speed USB Device port with embedded transceiver, a High Speed Multimedia Card Interface (HSMCI) supporting SDIO/SD/MMC, and a 128-bit wide Flash access with memory accelerator for deterministic 64 MHz execution. The device operates from a single supply of 1.62V to 3.6V with an internal 1.08V to 1.32V core regulator, and the SAM3S series is pin-to-pin compatible with AT91SAM7S legacy products in 48- and 64-pin versions, enabling low-risk migration of existing designs.
Architecturally, the Flash is accessed through a 128-bit wide bus feeding an accelerator, allowing zero-wait-state execution from fast SRAM paths even at the 64 MHz maximum core frequency. The peripheral set also includes an External Bus Interface (EBI) for memory expansion, and the industrial temperature grade supports rugged deployments.
Typical applications include industrial control panels, consumer devices with USB connectivity, data loggers using SD/MMC storage, and cost-sensitive embedded systems migrating from AT91SAM7S silicon.
Design consideration: budget the 64 KB Flash carefully; if firmware grows, ATSAM3S2AA-MU (128 KB) and ATSAM3S4AA-MU (256 KB) are drop-in same-package upgrades in the same QFN-48 footprint.
This page synthesizes verified datasheet data, drop-in alternatives, and practical design notes not consolidated in the manufacturer datasheet.
Drop-in alternatives for ATSAM3S1AA-MU — 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 ATSAM3S1AA-MU (same form factor and footprint) — differing in Pin Compatibility, SRAM, Core Processor, Package, Flash Memory.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
ATSAM3S2AA-MU
✅ Drop-In✓ In Stock
$3.6 / Unit
View Datasheet →ATSAM3S4AA-MU
✅ Drop-In✓ In Stock
$3.85 / Unit
View Datasheet →ATSAM3N1AA-MU
✅ Drop-In✓ In Stock
$3.18 / Unit
View Datasheet →ATSAM3N1AB-MU
✅ Drop-In✓ In Stock
$2.98 / Unit
View Datasheet →ATSAM3S1AA-MU Maximum Ratings & Electrical Characteristics
| Core | ARM Cortex-M3 (revision 2.0) |
| Core Size | 32-bit |
| Maximum Clock Speed | 64 MHz |
| Program Memory Size | 64 KB (64K x 8) Flash |
| RAM Size | 16 KB (16K x 8) |
| Supply Voltage Range | 1.62 V to 3.6 V |
| Core Voltage | 1.08 V to 1.32 V (internal regulator) |
| Package | 48-QFN (7x7 mm) |
| Number of I/O | 47 |
| USB | Full Speed USB Device with embedded transceiver |
| Memory Card Interface | High Speed MCI for SDIO/SD/MMC |
| External Bus Interface | Yes (EBI) |
| Instruction Set | Thumb-2 |
| Memory Protection | MPU (Memory Protection Unit) |
| Mounting Type | Surface Mount |
| Temperature Grade | Industrial |
| Series | SAM3S |
| Compatibility | Pin-to-pin compatible with AT91SAM7S (48- and 64-pin versions) |
ATSAM3S1AA-MU 48-qfn (7x7 mm) Pin Configuration Guide
Pin configuration for ATSAM3S1AA-MU (48-qfn (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 ATSAM3S1AA-MU.
Refer to the datasheet for full pin configuration.
Typical Applications
ATSAM3S1AA-MU is suitable for 6 applications: Industrial Control and Automation, USB-Connected Consumer Devices, SD/MMC Data Logging, Legacy AT91SAM7S Migration, Battery-Powered Portable Instruments, Networking and Communication Peripherals.
Industrial Control and Automation
The ATSAM3S1AA-MU fits industrial control nodes where a 64 MHz Cortex-M3 core, MPU for task isolation, and 1.62V to 3.6V single-supply operation meet typical 3.3V industrial rail requirements. The 47 GPIO lines drive relays, optocouplers, and status indicators, while multiple UARTs and the External Bus Interface (EBI) connect to displays and memory expansion. The Thumb-2 instruction set delivers compact code, and the 64 KB Flash with 128-bit accelerated access sustains deterministic control-loop execution. Because it is pin-to-pin compatible with the legacy AT91SAM7S, existing industrial PCBs can migrate without requalification of the layout.
Recommended
USB-Connected Consumer Devices
With a Full Speed USB Device port and embedded transceiver, the ATSAM3S1AA-MU implements USB peripherals such as HID devices, audio interfaces, and mass-storage gadgets without an external PHY, saving board area and BOM cost in the 7x7 mm QFN-48 footprint. The 64 MHz Cortex-M3 headroom comfortably sustains 12 Mbps Full Speed traffic, and the 64 KB Flash accommodates a standard USB stack plus application firmware. Designs scaling beyond 64 KB of code can drop in the ATSAM3S2AA-MU (128 KB) or ATSAM3S4AA-MU (256 KB) on the identical PCB, a migration path the SAM3S datasheet explicitly supports across the family.
Recommended
SD/MMC Data Logging
The High Speed MCI peripheral of the ATSAM3S1AA-MU supports SDIO, SD, and MMC cards, making it well suited to battery-powered data loggers. The card interface offloads data storage from internal Flash, while 16 KB of SRAM buffers sector writes for wear-leveling and efficient block transfers. The 1.62V to 3.6V supply range matches single-cell Li-ion and 3.3V rail designs, and the industrial temperature grade supports field deployments. Logging applications whose FAT stack plus application grows past 64 KB of code can migrate to the same-package ATSAM3S2AA-MU without PCB changes.
Recommended
Legacy AT91SAM7S Migration
According to the Atmel SAM3S datasheet, the SAM3S family is pin-to-pin compatible with AT91SAM7S legacy products in 48- and 64-pin versions, which makes the ATSAM3S1AA-MU a direct drop-in refresh for aging AT91SAM7S-based boards. Designers gain the Cortex-M3 revision 2.0 core with Thumb-2 density, an MPU, and an updated peripheral set while reusing proven PCB layouts and tooling. Firmware requires porting from ARM7TDMI to Cortex-M3, but Atmel/Microchip provides migration application notes covering clocking, peripheral register differences, and debug setup for a controlled transition.
Recommended
Battery-Powered Portable Instruments
Portable instruments benefit from the single 1.62V to 3.6V supply of the ATSAM3S1AA-MU with an internal core regulator, removing external LDO sequencing concerns, and from the compact 7x7 mm QFN-48 package that minimizes board area in handheld housings. The 64 MHz Cortex-M3 executes FFT and filtering routines for measurement front-ends, while 47 GPIO lines manage keypads, LCD segments, and sensor interfaces. Low-power operating modes in the SAM3S series extend battery life between charges, and the USB Device port provides convenient data offload to a PC without additional bridge circuitry.
Recommended
Networking and Communication Peripherals
Communication equipment accessories such as configuration panels, protocol converters, and auxiliary controllers leverage the ATSAM3S1AA-MU's multiple UARTs, USB Device port, and EBI. The 64 MHz core handles line-speed protocol translation for modest data rates, and the embedded USB transceiver implements device-side configuration interfaces. The External Bus Interface attaches parallel-bus peripherals or external memories when 16 KB SRAM is insufficient for buffering. Firmware over-the-air style updates can be staged via USB mass-storage boot from an SD card through the HSMCI, a pattern used widely in SAM3S reference designs.
Recommended
Recommended Products Summary
Engineering reference data for ATSAM3S1AA-MU — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | ATSAM3S2AA-MU | ATSAM3S4AA-MU | ATSAM3N1AA-MU |
|---|---|---|---|---|
| Package | 48-QFN (7x7 mm) | 48-QFN (7x7 mm) - same | 48-QFN (7x7 mm) - same | 48-QFN (7x7 mm) - same |
| Brand | Microchip Technology (Atmel) | Microchip Technology (Atmel) | Microchip Technology (Atmel) | Microchip Technology (Atmel) |
| Core / Max Speed | ARM Cortex-M3, 64 MHz | ARM Cortex-M3, 64 MHz | ARM Cortex-M3, 64 MHz | ARM Cortex-M3, 64 MHz |
| Flash Memory | 64 KB | 128 KB | 256 KB | 64 KB |
| USB Peripheral | Full Speed USB Device (embedded transceiver) | Full Speed USB Device | Full Speed USB Device | None (no USB) |
| 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 |
| Lifecycle Status | Active | Active | Active | Active |
Key Differentiators
- Embedded USB transceiver saves BOM cost (vs ATSAM3N1AA-MU)
- Largest same-footprint upgrade headroom (vs ATSAM3S4AA-MU)
- Cortex-M3 Thumb-2 density with MPU (vs ATSAM3S2AA-MU)
Design Notes
The 48-QFN (7x7 mm) package has a central exposed pad that must be soldered to a ground plane array for both thermal relief and a low-inductance ground return. Use a via array under the pad (typically 3x3 to 4x4 vias) and no-clean solder paste aperture design of 50-70% pad coverage. Decouple each VDD pin with 100 nF ceramic capacitors placed within 2 mm of the pin, plus one bulk 4.7 uF capacitor per supply domain.
Power the device from a single 3.3V rail within the 1.62V to 3.6V range; the internal regulator generates the 1.08V to 1.32V core domain, so never drive the core pins externally. If a switching pre-regulator feeds the MCU, add an LDO or ferrite bead stage to keep supply ripple within the datasheet limits, especially since USB operation specifies tighter VDD tolerance during enumeration.
Plan Flash capacity against firmware growth: at 64 KB, a USB stack plus FAT driver can consume over half of program memory. Because ATSAM3S2AA-MU and ATSAM3S4AA-MU are pin-to-pin drop-ins, reserve the footprint compatibility in your BOM strategy and keep linker scripts ready for both memory sizes. Also confirm USB D+/D- series resistor placement and ESD protection near the connector, since the embedded transceiver is sensitive to layout stubs.
Route USB D+/D- as a 90-ohm differential pair with length matching within 1 mm and avoid routing under the QFN exposed pad region. Keep the HSMCI clock line (MCCK) short and guard it with adjacent ground returns to reduce SD card read errors at high bus speeds. Per Atmel SAM3S design guidance, series termination on fast GPIO in EMI-sensitive designs is advised.
Compliance Information
RoHS and lead-free status consistent with Microchip standard policy for active SAM3S series parts; formal REACH and halogen-free declarations should be confirmed via Microchip's official product page material data.
