ATSAM3SD8BA-AU - 512KB Flash Cortex-M3 MCU 64MHz | Microchip
MPN: ATSAM3SD8BA-AU β Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $11.56 | $11.56 |
| 10 | $10.4 | $104.00 |
| 100 | $9.37 | $937.00 |
| 500 | $8.6 | $4,300.00 |
| 1,000 | $8.05 | $8,050.00 |
ATSAM3SD8BA-AU Overview
A 32-bit flash microcontroller is an embedded processing IC that integrates a processor core, program memory, data SRAM, and a rich set of peripherals on a single chip, forming the compute layer of the broader embedded systems hierarchy: Cortex-M3 core -> SAM3S MCU family -> 32-bit microcontroller -> embedded system IC. The SAM3S family descends from the Atmel AVR/ARM legacy and is pin-to-pin compatible with the AT91SAM7S series, providing an easy migration path for legacy designs.
Key features include the ARM Cortex-M3 revision 2.0 core with Memory Protection Unit (MPU) and Thumb-2 instruction set, a high-speed USB 2.0 device port with an integrated transceiver for plug-and-play connectivity, and a core supply domain of 1.08V to 1.32V with 1.62V to 3.6V I/O operation. The 47 general-purpose I/O lines, multiple USART/SPI/TWI serial channels, and a 12-bit DAC on the SD8 variant suit mixed analog-digital designs.
Technically, the device combines a high-speed flash controller with a multi-layer bus matrix, sustaining zero-wait-state execution in large measure and robust EMI tolerance. The integrated USB transceiver eliminates the external PHY, reducing BOM cost and board area. The embedded 12-bit DAC and hardware interleaved Flash architecture differentiate the SAM3SD8 from the SAM3S8 non-DAC sibling.
Typical applications include USB-connected industrial data loggers, test and measurement interfaces, patient monitoring accessories, and consumer appliances requiring USB firmware upgrade capability and moderate analog output capability.
For design, decouple the VDDCORE domain carefully and observe the 1.62V to 3.6V I/O constraint; the internal 1.2V core regulator requires an external output capacitor per the reference design.
This page synthesizes distributor pricing, verified alternatives, and practical design notes not found in the manufacturer datasheet.
Drop-in alternatives for ATSAM3SD8BA-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 ATSAM3SD8BA-AU (same form factor and footprint) β differing in RoHS Status, Supply Voltage, Core Processor, Package, Series.
Quick Comparison Tool β Select alternative parts for side-by-side comparison:
ATSAM3S8BA-AU
β Drop-Inβ In Stock
$6.4 / Unit
View Datasheet βATSAM3N4BA-MU
β Drop-Inβ In Stock
$3.48 / Unit
View Datasheet βATSAM3SD8BA-MUR
β Drop-Inβ In Stock
$3.98 / Unit
View Datasheet βATSAM3U4CA-AU
β Drop-Inπ Reference alternative (not in catalog)
ATSAM3SD8BA-AU Maximum Ratings & Electrical Characteristics
| Core Processor | ARM Cortex-M3 revision 2.0 |
| Core Size | 32-Bit |
| Maximum Clock Speed | 64 MHz |
| Flash Memory | 512KB (512K x 8) |
| SRAM | 100KB |
| Core Supply Voltage (VDDCORE) | 1.08 V to 1.32 V |
| I/O Supply Voltage | 1.62 V to 3.6 V |
| Number of I/O | 47 |
| USB | USB 2.0 High-Speed Device with integrated transceiver |
| Memory Protection Unit | Yes (MPU) |
| Instruction Set | Thumb-2 |
| Peripherals | DMA, 12-bit DAC, USART, SPI, TWI, PWM, ADC |
| Package | 64-LQFP (10 x 10 mm) |
| Mounting Type | Surface Mount |
| Operating Temperature | -40C to +85C (Industrial) |
| RoHS Status | Compliant (LQFP, Green, MRL) |
| Lifecycle Status | Active |
| Compatibility | Pin-to-pin compatible with AT91SAM7S legacy series |
ATSAM3SD8BA-AU 64-lqfp (10 x 10 mm) Pin Configuration Guide
Pin configuration for ATSAM3SD8BA-AU (64-lqfp (10 x 10 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 ATSAM3SD8BA-AU.
Refer to the datasheet for full pin configuration.
Typical Applications
ATSAM3SD8BA-AU is suitable for 6 applications: USB Data Loggers and Interfaces, Industrial Control and Automation Nodes, Test and Measurement Instruments, Medical Monitoring Accessories, Consumer Appliance Control Boards, Legacy AT91SAM7S Design Migration.
USB Data Loggers and Interfaces
The ATSAM3SD8BA-AU's USB 2.0 high-speed device controller with integrated transceiver delivers 480 Mbps transfers for fast data up/downloading, which is the defining requirement of industrial data loggers and PC-connected measurement interfaces. With 512KB Flash and 100KB SRAM, the MCU holds a USB mass-storage or CDC stack alongside the logging application without external memory. Placed as the single system controller, it enumerates plug-and-play on any host while its 1.62V to 3.6V I/O domain connects directly to 3.3V sensors. The robust EMI tolerance of the integrated PHY reduces external filtering needs, cutting BOM cost versus PHY-less MCU solutions requiring an external USB transceiver.
Recommended
Industrial Control and Automation Nodes
In factory automation, the ATSAM3SD8BA-AU combines a 64 MHz Cortex-M3 with 47 GPIO lines, multiple USART/SPI/TWI channels, PWM timers, and an industrial -40C to +85C temperature grade, making it a strong single-chip control node for motor-adjacent logic, valve controllers, and sensor aggregation. The MPU supports partitioned firmware with privileged RTOS kernels for functional robustness, while Thumb-2 code density keeps 512KB Flash sufficient for protocol-heavy applications. Its pin-to-pin compatibility with the AT91SAM7S legacy series allows migration of aging AT91SAM7S designs without PCB respin, extending the service life of installed industrial platforms at minimal engineering cost.
Recommended
Test and Measurement Instruments
Handheld and benchtop measurement accessories benefit from the ATSAM3SD8BA-AU's blend of fast USB upload, 12-bit on-chip DAC for test-signal generation, and ADC inputs for measurement acquisition. The 64 MHz core executes calibration math and DSP-lite filtering in real time, while the DAC provides stimulus output for sensor characterization - a differentiator versus the DAC-less SAM3S8. The 100KB SRAM buffers waveform captures before high-speed USB transfer to a host. Because the device is active-lifecycle with broad distributor availability (11 sources via Octopart as of 2026-09-19), instrument makers can rely on long-term sourcing for service and production builds alike.
Recommended
Medical Monitoring Accessories
Portable patient-monitoring accessories such as vital-sign pods and clinical data adapters require quiet analog, dependable USB connectivity, and industrial temperature margins, all of which the ATSAM3SD8BA-AU provides. The dual-rail architecture isolates the 1.08V to 1.32V core domain from the 1.62V to 3.6V I/O/analog domain, reducing digital noise coupling into measurement front ends. The 12-bit DAC can drive calibration or alarm-tone outputs, and the 480 Mbps USB link uploads patient data quickly to a monitor host. Designers should follow the datasheet's power-decoupling and VDDANA guidance to preserve signal integrity in the analog path.
Recommended
Consumer Appliance Control Boards
White-goods and small-appliance controllers use the ATSAM3SD8BA-AU for its combination of cost-effective 32-bit compute, USB service port for in-field firmware updates, and rich PWM/timer resources for actuator and display driving. The green LQFP package meets environmental directives, and the 512KB Flash comfortably holds GUI command sets, sensor-fusion routines, and USB DFU bootloaders concurrently. The 47 I/O lines interface LED arrays, keypads, and motor driver ICs directly at 3.3V logic. The pin-compatible SAM3S family lets appliance makers scale memory or peripherals across product tiers with a single PCB platform, amortizing layout and certification effort.
Recommended
Legacy AT91SAM7S Design Migration
Microchip explicitly positions the SAM3S family as pin-to-pin compatible with the AT91SAM7S legacy series, and the ATSAM3SD8BA-AU is the natural drop-in upgrade for AT91SAM7S boards approaching end-of-life sourcing risk. The Cortex-M3 revision 2.0 core with Thumb-2 delivers substantially higher throughput than the ARM7TDMI predecessor at the same 64 MHz-class clock, and 512KB Flash exceeds typical AT91SAM7S densities. Firmware requires peripheral-driver porting, but the identical 64-LQFP footprint means no PCB revision - a decisive advantage when recertification cost outweighs redesign. Verified active lifecycle status and 11-distributor availability further de-risk the migration window.
Recommended
Recommended Products Summary
Engineering reference data for ATSAM3SD8BA-AU β comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | ATSAM3S8BA-AU | ATSAM3N4BA-MU | ATSAM3U4CA-AU |
|---|---|---|---|---|
| Package | 64-LQFP (10 x 10 mm) | 64-LQFP (10 x 10 mm) - same | 64-LQFP - same | 64-LQFP |
| Brand | Microchip Technology (Atmel) | Microchip Technology | Microchip Technology | Microchip Technology (Atmel) |
| Flash Memory | 512KB | 512KB | 512KB | 256KB (2 x 128KB dual-bank) |
| USB High-Speed | Yes (integrated transceiver) | Yes | No | Yes (high-speed) |
| 12-bit DAC | Yes | No | No | No |
Key Differentiators
- Integrated 12-bit DAC (vs ATSAM3S8BA-AU)
- USB 2.0 high-speed with integrated transceiver (vs ATSAM3N4BA-MU)
- Largest memory in the SAM3S 64-LQFP tier (vs ATSAM3U4CA-AU)
Design Notes
The ATSAM3SD8BA-AU uses a dual-rail architecture: VDDCORE must be held at 1.08V to 1.32V while VDDIO/VDDANA accept 1.62V to 3.6V. The internal 1.2V regulator requires the datasheet-specified output capacitance on its VDDCORE pin - do not omit it, or the core rail may oscillate during flash programming. Estimated: at 64 MHz the core current is typically in the tens of mA range per the SAM3S datasheet current-consumption tables, so a single 3.3V LDO input with a low-ESR 10uF bulk plus 0.1uF per supply pin is a reliable starting point.
Place 0.1uF ceramic decoupling capacitors within 2 mm of each VDDIO and VDDCORE pin pair, with one bulk 10uF per supply domain. Route the USB D+/D- pair as a 90-ohm differential pair with length matching better than 1 mm; the integrated high-speed transceiver still needs controlled-impedance layout at 480 Mbps. Keep the VDDANA domain on a quiet island with its own ferrite bead and local 1uF + 10nF caps when using the ADC/DAC, since switching noise on the analog rail directly degrades the 12-bit converter effective number of bits.
Designers migrating from AT91SAM7S must not assume identical register maps - the SAM3S peripheral programming model differs even though the pinout is compatible, so re-verify the PIO multiplexer table for every pin before board sign-off. Also remember the I/O domain is limited to 3.6V absolute maximum: 5V-tolerant logic does not exist on this part, so level-shift any 5V signals. Finally, the USB high-speed PHY requires the correct crystal/oscillator accuracy per the datasheet USB chapter; marginal clock accuracy is the most common cause of enumeration failures.
Compliance Information
Mouser listing describes the package as 'LQFP, Grn, IT, MRL' indicating green (halogen-free), lead-free, industrial temperature, mold-release-agent compliant construction. REACH and conflict-minerals status not stated in provided data.
