ATSAM3A8CA-AU - 84MHz Cortex-M3 MCU, 512KB Flash | Microchip
MPN: ATSAM3A8CA-AU β Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $9.2 | $9.20 |
| 10 | $8.45 | $84.50 |
| 100 | $7.6 | $760.00 |
| 500 | $6.95 | $3,475.00 |
| 1,000 | $6.3 | $6,300.00 |
ATSAM3A8CA-AU Overview
A flash microcontroller is a single-chip embedded processor that integrates a CPU core, program flash, SRAM, clock system, and a rich set of peripherals onto one die. Within the power-management hierarchy, an MCU such as the SAM3A sits at the lowest level of a control system, directly driving actuators, communications transceivers, and user interfaces. The ATSAM3A8CA-AU belongs to the SAM3A family, a branch of the Atmel (now Microchip) SAM3 series based on the ARM Cortex-M3 revision 2.0 processor.
Key features include the Thumb-2 instruction set, a Memory Protection Unit (MPU), a 24-bit SysTick timer, and a Nested Vector Interrupt Controller (NVIC). Peripheral connectivity is extensive: CAN, I2C (Two-Wire Interface), IrDA, LIN, MMC/SD, SPI, SSC (synchronous serial controller), and UART/USART ports. A distinctive family feature is the integrated high-speed USB 2.0 device transceiver, enabling fast firmware up/downloading and plug-and-play serial interconnectivity with robust EMI tolerance.
Architecturally, the Cortex-M3 revision 2.0 core delivers deterministic interrupt latency through the NVIC and efficient code density through Thumb-2, while the dual-bank flash arrangement supports safe in-application firmware updates. The 96KB SRAM split into 64KB + 32KB banks allows concurrent buffering of communications data and application variables.
Typical applications include industrial CAN networking nodes, USB-connected industrial and medical instruments, motor-control interfaces via SSC and UART/USART, and embedded gateways that bridge CAN buses to USB or SPI peripherals.
Design consideration: the device operates from a 1.62V to 3.6V single supply (typical 1.8V, 2.5V, or 3.3V systems), so ensure the VDDIO and VDDCORE domains are properly decoupled and that the 12MHz crystal or internal RC source meets the PLL lock requirements before enabling the 84MHz clock tree.
This page synthesizes distributor pricing signals, drop-in family alternatives, and practical design notes not found in the manufacturer datasheet.
Drop-in alternatives for ATSAM3A8CA-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 ATSAM3A8CA-AU (same form factor and footprint) β differing in Package, Connectivity, Series, Supply Voltage, Flash Memory.
Quick Comparison Tool β Select alternative parts for side-by-side comparison:
ATSAM3X8CA-AU
β Drop-Inβ In Stock
$7.18 / Unit
View Datasheet βATSAM3A8CA-CU
β Drop-In β οΈ εζ°εΎ ιͺθ―π Reference alternative (not in catalog)
ATSAM3S8CA-AU
β Drop-In β οΈ εζ°εΎ ιͺθ―π Reference alternative (not in catalog)
ATSAM3S4CA-AU
β Drop-In β οΈ εζ°εΎ ιͺθ―π Reference alternative (not in catalog)
ATSAM3SD8CA-AU
β Drop-Inβ In Stock
$3.14 / Unit
View Datasheet βATSAM3A8CA-AU Maximum Ratings & Electrical Characteristics
| Core Processor | ARM Cortex-M3 revision 2.0 |
| Core Size | 32-Bit |
| Maximum Clock Speed | 84 MHz |
| Flash Memory | 512KB (2 x 256KB banks) |
| SRAM | 96KB (64KB + 32KB banks) |
| Supply Voltage | 1.8 V / 2.5 V / 3.3 V (1.62 V to 3.6 V range) |
| Connectivity | CAN, I2C, IrDA, LIN, MMC, SPI, SSC, UART/USART, USB |
| USB | High-speed USB 2.0 device with integrated transceiver |
| Instruction Set | Thumb-2 |
| Memory Protection | MPU (Memory Protection Unit) |
| SysTick Timer | 24-bit |
| Interrupt Controller | NVIC (Nested Vector Interrupt Controller) |
| Package | 100-LQFP (14 x 14 mm) |
| Mounting Type | Surface Mount |
| RoHS Status | Compliant (Green package per Mouser listing) |
| Series | SAM3A |
ATSAM3A8CA-AU 100-lqfp (14 x 14 mm) Pin Configuration Guide
Pin configuration for ATSAM3A8CA-AU (100-lqfp (14 x 14 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 ATSAM3A8CA-AU.
Refer to the datasheet for full pin configuration.
Typical Applications
ATSAM3A8CA-AU is suitable for 6 applications: Industrial CAN Networking Nodes, High-Speed USB Instruments, Motor Control Interfaces, Embedded CAN-to-USB Gateways, Battery-Powered Data Loggers, Building Automation Controllers.
Industrial CAN Networking Nodes
The ATSAM3A8CA-AU fits industrial CAN nodes because it integrates a CAN controller alongside the 84 MHz Cortex-M3 core and 96KB SRAM, providing the buffering headroom for multi-frame message queues in automation and factory networks. In a typical node, the MCU reads sensors via SPI or I2C, processes protocol logic in Thumb-2 code, and streams CAN frames through an external transceiver such as the Microchip MCP2551. The 1.62V to 3.6V supply tolerance and green industrial-temperature package suit 24V industrial cabinets with 3.3V logic rails. Unlike 8-bit MCUs, the dual-bank 512KB flash supports field firmware updates over the CAN bus itself, so deployed equipment can be upgraded without physical access, a decisive benefit in large installations.
Recommended
High-Speed USB Instruments
Instruments that stream data to a PC benefit directly from the ATSAM3A8CA-AU's integrated high-speed USB 2.0 device transceiver. Because the PHY is on-chip, the design needs only USB termination resistors and a 480 Mbps-compliant layout, avoiding an external ULPI PHY and its 60 MHz interface routing. The 64KB + 32KB SRAM split lets one bank serve as USB DMA buffers while the other holds ADC or SSC acquisition data, sustaining wire-speed transfers. The datasheet's stated plug-and-play interconnectivity and robust EMI tolerance make it suitable for lab meters, data loggers, and medical diagnostic boxes where the USB link doubles as the power source. Firmware upload via USB using SAM-BA also simplifies production programming and end-user updates.
Recommended
Motor Control Interfaces
The ATSAM3A8CA-AU serves as the communication and supervision controller in motor-drive systems, complementing a dedicated motor driver. Its SSC (Synchronous Serial Controller) handles encoder or codec interfaces with hardware support, while multiple UART/USART ports link to drives, HMIs, and PLC backplanes. The 84 MHz Cortex-M3 with NVIC provides deterministic interrupt response for time-critical control loops, and the MPU enables isolation of safety-critical firmware regions. CAN connectivity integrates the controller into industrial fieldbus architectures for distributed motion control. The 512KB flash accommodates protocol stacks such as CANopen alongside the application, and the dual-bank arrangement allows bootloader-based updates so drive firmware can be revised in the field without replacing hardware.
Recommended
Embedded CAN-to-USB Gateways
Bridging CAN bus networks to PCs is a classic fit for this MCU because both interfaces are native peripherals: the CAN controller on one side and the high-speed USB device transceiver on the other. A gateway built on the ATSAM3A8CA-AU tunnels CAN frames over USB at 480 Mbps, far exceeding typical 1 Mbps CAN utilization, so the bridge never becomes the bottleneck. The 96KB SRAM buffers burst traffic during bus-load peaks, and the MPU separates the firmware update region from the routing engine. Commercial USB-CAN adapters built on the SAM3A/SAM3X family exploit exactly this combination. The 100-LQFP 14x14 mm footprint keeps the adapter PCB within a compact housing suitable for portable diagnostics tools.
Recommended
Battery-Powered Data Loggers
For data loggers, the ATSAM3A8CA-AU balances throughput and power: the Cortex-M3 executes logging and compression code quickly so the CPU can return to sleep states rapidly, and the 1.62V to 3.6V supply range allows direct operation from a single lithium or three-cell alkaline stack with an LDO. Peripherals including I2C and SPI connect flash storage and sensors, while the MMC/SD interface writes directly to removable cards without a software bit-banging overhead. The dual-bank flash stores a bootloader in one bank and application plus logging firmware in the other, enabling safe field updates of deployed loggers. High-speed USB provides fast log dumps to a host PC when the unit is docked, avoiding slow serial extraction.
Recommended
Building Automation Controllers
Building automation controllers require multiple serial channels and a robust fieldbus, both of which the ATSAM3A8CA-AU provides natively: several UART/USART ports for metering and sensor loops, I2C for environmental sensors, SPI for displays and memory, and CAN for the controller-area backbone. The 84 MHz core runs protocol stacks such as CANopen or device profiles in 512KB flash with room to spare, and 96KB SRAM supports multiple concurrent sessions. The green industrial-temperature 100-LQFP package meets the thermal and compliance requirements of control cabinets. Thumb-2 code density keeps external memory unnecessary, and the 24-bit SysTick plus NVIC deliver the periodic timing precision that HVAC scheduling and lighting control demand.
Recommended
Recommended Products Summary
Engineering reference data for ATSAM3A8CA-AU β comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | ATSAM3X8CA-AU | ATSAM3A8CA-CU | ATSAM3S8CA-AU | ATSAM3S4CA-AU | ATSAM3SD8CA-AU |
|---|---|---|---|---|---|---|
| Package | 100-LQFP (14x14 mm) | 100-LQFP (14x14 mm) - same | 100-LQFP (14x14 mm) - same | 100-LQFP (14x14 mm) - same | 100-LQFP (14x14 mm) - same | 100-LQFP (14x14 mm) - same |
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Core / Speed | Cortex-M3, 84 MHz | Cortex-M3, 84 MHz | Cortex-M3, 84 MHz | Cortex-M3, 84 MHz | Cortex-M3, 84 MHz | Cortex-M3, 84 MHz |
| Flash Memory | 512KB (2 x 256KB) | 512KB (2 x 256KB) | 512KB (2 x 256KB) | 512KB | 256KB | 512KB |
| SRAM | 96KB (64KB + 32KB) | 96KB (64KB + 32KB) | 96KB (64KB + 32KB) | 128KB | 64KB | 96KB |
| CAN Controller | Yes | Yes | Yes | No | No | No |
| USB Speed | High-speed (480 Mbps), integrated transceiver | High-speed, integrated transceiver | High-speed, integrated transceiver | Full-speed only | Full-speed only | Full-speed only |
| Series | SAM3A (CAN-centric) | SAM3X (USB-centric) | SAM3A | SAM3S (general purpose) | SAM3S (general purpose) | SAM3SD (device controller) |
| Supply Voltage | 1.8V / 2.5V / 3.3V (1.62V-3.6V) | 1.62V-3.6V | 1.62V-3.6V | 1.62V-3.6V | 1.62V-3.6V | 1.62V-3.6V |
Key Differentiators
- CAN controller plus high-speed USB on one die (vs ATSAM3S8CA-AU)
- Dual-bank 512KB flash for field updates (vs ATSAM3S4CA-AU)
- Same footprint upgrade path with more flash-class options (vs ATSAM3SD8CA-AU)
Design Notes
The SAM3A uses separate VDDCORE and VDDIO supply domains, both within the 1.62V to 3.6V operating range per the Microchip datasheet. Decouple each supply pin with 100nF ceramic capacitors placed within 2mm of the pin, plus one 10uF bulk capacitor per domain. If core and I/O run at different rails, sequence VDDCORE before or with VDDIO to avoid latch-up risk. Estimated: at 84 MHz typical core current is in the tens of milliamps, so a small LDO such as the MCP1700 suffices for battery designs; verify against the datasheet power consumption tables for your clock configuration.
The 100-LQFP (14x14 mm) has 0.5mm pin pitch, which requires careful solder paste stencil design; use 1:1 aperture with 100-120um thickness to prevent bridging. Route the high-speed USB DP/DM pair as a 90-ohm differential pair with length matching better than 1mm, keeping them away from the 12MHz crystal. The crystal load capacitors must match the datasheet CL specification, and the crystal should sit within 5mm of the OSC pins with a ground guard ring for reliable PLL lock at 84 MHz.
Do not assume SAM3A and SAM3S 100-pin parts are interchangeable despite the identical package: peripheral muxing on shared pins differs, and the SAM3S lacks CAN and high-speed USB. Always cross-check the datasheet pin multiplexing tables before a board spin. Second, the dual-bank flash bootloader requires the GPNVM bits to be set correctly when migrating firmware between banks; an incorrect GPNVM state leaves the part running from the wrong bank after reset. Third, unused I/O should be grounded or driven, never left floating, to avoid excess current in EMI-sensitive industrial environments.
Compliance Information
Green package, industrial temperature per Mouser listing ('QFP100, GREEN IND TEMP'); -AU suffix denotes Microchip lead-free/RoHS package. REACH and halogen-free declarations not stated in available data - verify on Microchip compliance portal.