ATSAM3S1AA-AU - 64MHz Cortex-M3 MCU 64KB Flash | Microchip
MPN: ATSAM3S1AA-AU β Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $4.2 | $4.20 |
| 10 | $3.78 | $37.80 |
| 100 | $3.36 | $336.00 |
| 500 | $3.02 | $1,510.00 |
| 1,000 | $2.68 | $2,680.00 |
ATSAM3S1AA-AU Overview
A microcontroller (MCU) is a single-chip embedded computer that integrates a processor core, non-volatile program memory, RAM, and peripherals such as timers, serial interfaces, and analog converters onto one die. Within the embedded hierarchy, the ATSAM3S1AA-AU sits in the general-purpose 32-bit MCU class, part of the SAM3S family of ARM-based flash MCUs that succeeded Atmel's AT91 legacy line and is now sold under Microchip Technology.
Key differentiating specifications include the 64 MHz Cortex-M3 core with Thumb-2 instruction efficiency, 1.62V to 3.6V single-supply operation with an internal 1.2V regulator (core supply 1.08V to 1.32V), and a rich peripheral set typical of the SAM3S family, including USB device support, multiple USART/SPI/TWI serial channels, an ADC, PWM channels, and a real-time clock calendar for low-power designs. The device is pin-to-pin compatible with the SAM3N series, giving designers a migration path between cost- and feature-optimized variants.
Architecturally, the device combines the three-stage ARM Cortex-M3 pipeline with Atmel's flash memory technology and a multi-layer bus matrix, allowing peripheral DMA access without loading the CPU. Power management controllers (PMC) permit per-peripheral clock gating, supporting the low active and sleep current levels the SAM3S family is known for.
Typical applications include industrial control nodes, consumer and portable battery-powered devices, printer and POS peripherals, and sensor-hub products that need USB connectivity in a compact 48-pin footprint.
When designing with this device, budget flash utilization carefully: 64 KB is adequate for bare-metal and FreeRTOS-class firmware, but code size growth may favor the pin-compatible ATSAM3S1BA-AU (128 KB) upgrade.
This page synthesizes verified distributor data, drop-in same-package alternatives, and practical design notes not found on the manufacturer's own product pages.
Drop-in alternatives for ATSAM3S1AA-AU 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 ATSAM3S1AA-AU (same form factor and footprint) β differing in Core Processor, Pin Compatibility, Interrupt Controller, Flash Memory, Maximum Clock Speed.
Quick Comparison Tool β Select alternative parts for side-by-side comparison:
ATSAM3S1BA-AU
β Drop-In β οΈ εζ°εΎ ιͺθ―π Reference alternative (not in catalog)
ATSAM3S2AA-AU
β Drop-In β οΈ εζ°εΎ ιͺθ―π Reference alternative (not in catalog)
ATSAM3N1AA-AU
β Drop-Inβ In Stock
Contact for price
View Datasheet βATSAM3N2AA-AU
β Drop-Inβ In Stock
$2.68 / Unit
View Datasheet βATSAM3S1AA-AU Maximum Ratings & Electrical Characteristics
| Core Processor | ARM Cortex-M3 |
| Core Size | 32-bit |
| Maximum Clock Speed | 64 MHz |
| Flash Memory | 64 KB (64K x 8) |
| SRAM | 16 KB (16K x 8) |
| Supply Voltage (Vdd) | 1.62 V to 3.6 V |
| Core Supply Voltage | 1.08 V to 1.32 V (internal regulator) |
| I/O Count | 47 |
| Package | 48-LQFP (7x7 mm), gull-wing leads |
| Mounting Type | Surface Mount |
| Program Memory Type | Flash |
| Connectivity | USB device, USART, SPI, TWI (I2C) |
| Life Cycle Stage | Active |
| RoHS Status | RoHS compliant (per distributor listings) |
ATSAM3S1AA-AU 48-lqfp (7x7 mm), gull-wing leads Pin Configuration Guide
Pin configuration for ATSAM3S1AA-AU (48-lqfp (7x7 mm), gull-wing leads 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-AU.
Refer to the datasheet for full pin configuration.
Typical Applications
ATSAM3S1AA-AU is suitable for 6 applications: Industrial Control Nodes, Battery-Powered Portable Devices, USB Peripherals and POS Equipment, Sensor Hubs and Data Loggers, Consumer Appliance Control, Embedded Networking and Gateways.
Industrial Control Nodes
The ATSAM3S1AA-AU fits industrial control and monitoring nodes where a 64 MHz Cortex-M3 with 64 KB flash covers deterministic control loops and protocol handling. Its 47 GPIO lines, multiple USART/SPI/TWI channels, and PWM outputs drive relays, sensors, and HMI elements, while the 1.62V to 3.6V supply tolerates noisy 3.3V rails found on factory floors. The multi-layer bus matrix and peripheral DMA offload the CPU during serial polling, keeping interrupt latency low. Because it is pin-to-pin compatible with SAM3N variants, one PCB can serve both USB-enabled and cost-reduced product tiers.
Recommended
Battery-Powered Portable Devices
The SAM3S family is characterized by reduced power consumption, and the ATSAM3S1AA-AU applies that to portable products. The wide 1.62V to 3.6V supply range permits direct operation from lithium cells or two-cell packs, while the power management controller gates clocks to unused peripherals and supports sleep modes that extend battery life. With 64 KB flash it runs power-optimized bare-metal or RTOS firmware in the 7x7 mm 48-LQFP footprint, and the internal core regulator (1.08V to 1.32V) removes the cost of an external buck converter for the core rail in space-constrained handheld designs.
Recommended
USB Peripherals and POS Equipment
The integrated USB 2.0 full-speed device port distinguishes the SAM3S from the pin-compatible SAM3N series, making the ATSAM3S1AA-AU a natural fit for printers, scanners, card readers, and point-of-sale terminals. At 64 MHz with 16 KB SRAM it services USB CDC/HID/MSC classes with room for buffering, while USART and TWI interfaces talk to thermal print heads, secure elements, and keypads. The drop-in compatibility with larger-memory SAM3S1BA-AU variants gives an upgrade path if the USB stack and application firmware outgrow 64 KB flash.
Recommended
Sensor Hubs and Data Loggers
With multiple USART, SPI, and TWI (I2C) interfaces plus ADC inputs, the ATSAM3S1AA-AU aggregates data from analog and digital sensors in logging and hub applications. Peripheral DMA streams ADC and serial data into the 16 KB SRAM buffer without CPU intervention, and the real-time clock calendar supports timestamped logging across sleep/wake cycles. The 47 GPIO count permits direct control of channel multiplexers, LED indication, and storage media interfaces, while 64 KB flash accommodates the acquisition firmware, local filtering, and a modest FAT or ring-buffer file layer.
Recommended
Consumer Appliance Control
In white goods, small appliances, and HVAC controllers, the ATSAM3S1AA-AU provides the processing headroom for touch-interface polling, motor control PWM, and communications at modest cost. The 64 MHz Cortex-M3 executes control and UI firmware comfortably within 64 KB flash, and RoHS-compliant gull-wing LQFP packaging suits standard reflow assembly. Designers value the single-supply 1.62V to 3.6V operation and the ability to migrate to pin-compatible SAM3N parts to de-cost non-connectivity product variants without redesigning the control board.
Recommended
Embedded Networking and Gateways
For compact gateways and sub-node networking, the ATSAM3S1AA-AU combines USB device connectivity for host-facing links with multiple USART/SPI channels for RS-485, CAN-adjacent, or radio-module backhaul. The 64 MHz core and bus-matrix architecture keep protocol stacks responsive while DMA moves payloads, and sleep modes suit intermittently powered edge nodes. The 48-LQFP (7x7 mm) footprint conserves board area in dense I/O modules, and firmware portability across the pin-compatible SAM3S/SAM3N range shortens development cycles across product families.
Recommended
Recommended Products Summary
Engineering reference data for ATSAM3S1AA-AU β comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | ATSAM3S1BA-AU | ATSAM3S2AA-AU | ATSAM3N1AA-AU | ATSAM3N2AA-AU |
|---|---|---|---|---|---|
| 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 |
| Brand | Microchip Technology (Atmel) | Microchip Technology (Atmel) | Microchip Technology (Atmel) | Microchip Technology (Atmel) | Microchip Technology (Atmel) |
| Core / 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 | 64 KB | 128 KB | 128 KB | 64 KB | 128 KB |
| SRAM | 16 KB | 20 KB | 32 KB | 16 KB | 24 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 |
| USB Device Port | Yes (full-speed device) | Yes (full-speed device) | Yes (full-speed device) | No (SAM3N omits USB) | No (SAM3N omits USB) |
| Lifecycle Status | Active | Active | Active | Active | Active |
Key Differentiators
- Lowest-cost SAM3S entry point with USB (vs ATSAM3S1BA-AU)
- USB device peripheral absent in the pin-compatible SAM3N series (vs ATSAM3N1AA-AU)
- Larger flash headroom available in-family without respin (vs ATSAM3S2AA-AU)
Design Notes
The ATSAM3S1AA-AU runs its Cortex-M3 core from an internal 1.08V to 1.32V regulator, so the external 1.62V to 3.6V VDDIO/VDDCORE inputs need only proper decoupling - do not feed an external core rail unless you are using the non-regulator package option. Place 100 nF ceramic capacitors at each VDD pin pair plus a 4.7 uF bulk capacitor near the device, per Atmel SAM3S hardware design guidance. Estimated: at 64 MHz active execution, core current is typically in the tens-of-mA range, so IR drop on the 3.3V rail is negligible with 0.5 oz copper.
The 48-LQFP (7x7 mm) footprint requires a standard 0.5 mm pitch gull-wing land pattern; use the package drawing in the manufacturer datasheet rather than a generic footprint, and keep the land pattern slightly extended (heel fillet) for inspectable solder joints. Route the USB D+/D- pair as a 90-ohm differential pair with length matching within 1 mm if the device port is used. The SWD pins (SWDIO/SWCLK) should be broken out to a 2x5 or single-row debug header during PCB design - retrofitting debug access on a potted or enclosed product is a common and costly pitfall.
Flash sizing is the most frequent problem: 64 KB fills quickly with a USB stack plus RTOS. Confirm code size before locking the design; the pin-compatible ATSAM3S1BA-AU (128 KB) is the no-respin upgrade. Also note that -MU suffix parts are QFN packages and cannot replace the -AU LQFP on the same footprint. Verify the operating temperature suffix requirement (-AU covers industrial range per Atmel ordering code, but confirm the exact range in the current Microchip datasheet) and erase-while-programming flash behavior when planning in-field firmware updates via SAM-BA.
Compliance Information
RoHS compliant per distributor listings for the -AU LQFP package. Full REACH, halogen-free, and conflict-minerals declarations should be obtained from the official Microchip environmental certificate.
