ATSAM3A4CA-CU - 84MHz Cortex-M3 MCU 256KB Flash | Microchip
MPN: ATSAM3A4CA-CU β Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $8.2 | $8.20 |
| 10 | $7.45 | $74.50 |
| 100 | $6.65 | $665.00 |
| 500 | $5.95 | $2,975.00 |
| 1,000 | $5.4 | $5,400.00 |
ATSAM3A4CA-CU Overview
A microcontroller unit (MCU) is a single-chip embedded computer that integrates a processor core, program memory, data memory, and peripherals such as timers, serial interfaces, and analog blocks. MCUs sit at the device level of the embedded-systems hierarchy - below system-on-chip (SoC) and application processors - and the SAM3A belongs to the broader ARM Cortex-M family of 32-bit microcontroller cores, which in turn belongs to the ARM architecture ecosystem.
Key features include the ARM Cortex-M3 revision 2.0 core executing the Thumb-2 instruction set, a Memory Protection Unit (MPU), a 24-bit SysTick counter, and a Nested Vectored Interrupt Controller (NVIC) for deterministic interrupt latency. The dual-bank flash architecture enables safe in-application programming, while the dual-bank SRAM supports efficient DMA transfers without bus contention. Peripherals cover automotive-relevant connectivity: two CAN controllers, USART with ISO7816, IrDA and LIN support, SPI, SSC (I2S audio), TWI (I2C-compatible), and an MMC/SD memory card interface.
The device operates from a 1.62V to 3.6V single supply (typical 1.8V, 2.5V, or 3.3V rails) across an industrial temperature range, and the CU suffix denotes a RoHS-compliant, halogen-free green package. The 9x9 mm 100-ball TFBGA footprint delivers high I/O density for compact industrial PCBs.
Typical applications include industrial automation nodes, CAN networking gateways, motor control and power-conversion supervisory systems, and embedded HMI or data-logging equipment.
When designing with the ATSAM3A4CA-CU, budget the BGA footprint carefully: 0.8 mm ball pitch requires controlled-impedance routing for CAN and SSC signals, and the power distribution network should include decoupling per the SAM3X/SAM3A datasheet power-rail guidance.
This page synthesizes distributor pricing, drop-in same-family alternatives, and practical design notes not found in the manufacturer datasheet.
Drop-in alternatives for ATSAM3A4CA-CU 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 ATSAM3A4CA-CU (same form factor and footprint) β differing in Flash Memory, Package, Series, Core Processor, Core Size.
Quick Comparison Tool β Select alternative parts for side-by-side comparison:
ATSAM3A4CA-AU
β Drop-In β οΈ εζ°εΎ ιͺθ―β In Stock
$12.3 / Unit
View Datasheet βATSAM3A8CA-CU
β Drop-In β οΈ εζ°εΎ ιͺθ―π Reference alternative (not in catalog)
ATSAM3X4CA-CU
β Drop-Inβ In Stock
$6.1 / Unit
View Datasheet βATSAM3S4CA-CUR
β Drop-Inπ Reference alternative (not in catalog)
ATSAM3U2CA-CU
β Drop-Inπ Reference alternative (not in catalog)
ATSAM3A4CA-CU Maximum Ratings & Electrical Characteristics
| Core Processor | ARM Cortex-M3 revision 2.0 |
| Core Size | 32-bit, single-core |
| Maximum Clock Speed | 84 MHz |
| Flash Memory | 256KB (256K x 8), 2 x 128KB banks |
| SRAM | 64KB, 2 x 32KB banks |
| Supply Voltage Range | 1.62 V to 3.6 V (1.8 V / 2.5 V / 3.3 V typical) |
| Connectivity | CAN, I2C (TWI), IrDA, LIN, MMC/SD, SPI, SSC, UART/USART |
| Instruction Set | Thumb-2 |
| Memory Protection | MPU (Memory Protection Unit) |
| SysTick Timer | 24-bit |
| Interrupt Controller | NVIC (Nested Vectored Interrupt Controller) |
| Package | 100-TFBGA (9 x 9 mm) |
| Mounting Type | Surface Mount |
| Operating Temperature | -40C to +85C (industrial) |
| RoHS Status | Compliant (green package) |
| Series | SAM3A |
ATSAM3A4CA-CU 100-tfbga (9 x 9 mm) Pin Configuration Guide
Pin configuration for ATSAM3A4CA-CU (100-tfbga (9 x 9 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 ATSAM3A4CA-CU.
Refer to the datasheet for full pin configuration.
Typical Applications
ATSAM3A4CA-CU is suitable for 6 applications: Industrial CAN Networking Nodes, Motor Control and Power Conversion Supervision, Embedded Data Loggers, Human-Machine Interface (HMI) Panels, Gateways and Protocol Converters, Building Automation Sensors and Actuators.
Industrial CAN Networking Nodes
The ATSAM3A4CA-CU is well suited for industrial CAN nodes because its SAM3A peripheral set centers on dual CAN controllers alongside SPI, TWI, and USART with LIN support, all serviced by a DMA controller and dual 32KB SRAM banks. At 84 MHz the Cortex-M3 core handles CANopen or DeviceNet protocol stacks with significant headroom, while the MPU enables functional partitioning of stack and application memory. Deployed as a sensor or actuator node between a 24V industrial bus and the CAN physical layer, the MCU runs from a 3.3V rail derived by a buck converter (for example, Microchip MCP16331) with a CAN transceiver on the CAN pins. The dual-bank flash permits field firmware updates over CAN without an external programmer.
Recommended
Motor Control and Power Conversion Supervision
In motor drives and power converters, the ATSAM3A4CA-CU supervises the control loop front end: its SSC and timer resources generate PWM timing references, the 12-bit ADC-free SAM3A architecture pairs with external precision ADCs over SPI for current and voltage sampling, and the CAN interface reports status to a higher-level drive controller. The 84 MHz Cortex-M3 with Thumb-2 executes PIDs and state machines deterministically under the NVIC, and the 64KB SRAM buffers fault logs and telemetry. Designers typically allocate one SRAM bank to DMA circular buffers and the other to the application stack, avoiding contention. The 1.62V-3.6V supply tolerance allows direct operation from 3.3V logic rails shared with gate-driver logic.
Recommended
Embedded Data Loggers
The integrated MMC/SD card interface (MCI) makes the ATSAM3A4CA-CU a natural fit for embedded data loggers writing sensor streams to SD media. The DMA controller moves ADC or USART-received samples into SRAM without CPU intervention, and the 84 MHz core supports filesystem middleware such as FatFS with real-time margins. Dual-bank flash enables logging-application updates in the field, and the industrial -40C to +85C range suits unheated cabinets and outdoor enclosures. Typical designs clock the MCI at up to tens of MHz for multi-megabyte-per-second write throughput, buffering through one 32KB SRAM bank while the application runs from the other bank and executes from flash.
Recommended
Human-Machine Interface (HMI) Panels
For compact HMI panels, the ATSAM3A4CA-CU drives character/graphical LCD or OLED modules over its parallel or serial buses, reads keypads and rotary encoders through its PIO controller, and communicates with a PLC or host over CAN or USART. The 256KB flash accommodates a lightweight GUI framework plus localization string tables, while the 64KB SRAM holds framebuffer regions for small displays (for example, 128x64 monochrome panels fit comfortably in a single SRAM bank). The 100-TFBGA 9x9 mm package keeps board area small for behind-panel mounting, and Thumb-2 code density reduces flash pressure relative to ARM7-class parts historically used in HMI retrofits.
Recommended
Gateways and Protocol Converters
The ATSAM3A4CA-CU bridges field buses as a protocol converter: dual CAN plus multiple USARTs, SPI, TWI, and SSC let one device translate between CAN, Modbus-over-RS-485 (via a LIN/USART-capable transceiver), and serial sensor protocols simultaneously. The NVIC prioritizes time-critical CAN reception over background UART parsing, and the 24-bit SysTick provides a stable timebase for protocol timeouts. The 84 MHz core sustains aggregate throughput typical of industrial gateways handling a few thousand frames per second. Dual-bank SRAM separates DMA receive rings from protocol state, and the MPU can isolate the communication stack from application logic for safer field updates over CAN or serial bootloader.
Recommended
Building Automation Sensors and Actuators
The ATSAM3A4CA-CU serves as the main controller in building automation end points such as damper actuators, VAV controllers, and environmental sensor boards. Its TWI (I2C-compatible) and SPI interfaces connect temperature, humidity, and pressure sensors, while CAN links the node to the building controller backbone. The 1.62V-3.6V supply range and low-power wait modes support nodes powered from limited 3.3V auxiliary supplies, and the industrial temperature rating covers rooftop and mechanical-room installations. The 256KB dual-bank flash stores a full application plus a CAN bootloader for remote reprogramming during commissioning, and the MPU partitions the network stack from control firmware to improve field reliability.
Recommended
Recommended Products Summary
Engineering reference data for ATSAM3A4CA-CU β comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | ATSAM3A4CA-AU | ATSAM3A8CA-CU | ATSAM3X4CA-CU | ATSAM3S4CA-CUR | ATSAM3U2CA-CU |
|---|---|---|---|---|---|---|
| Package | 100-TFBGA (9x9) | 100-TFBGA (9x9) - same | 100-TFBGA (9x9) - same | 100-TFBGA - same family | 100-TFBGA - same family | 100-TFBGA - same family |
| 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 / 120 MHz class per SAM3S family | Cortex-M3 / 96 MHz class per SAM3U family |
| Flash | 256KB (2 x 128KB banks) | 256KB | 512KB | 256KB | 256KB | 128KB |
| SRAM | 64KB (2 x 32KB banks) | 64KB | 96KB | 96KB | 64KB | 32KB |
| Ethernet MAC | No | No | No | Yes | No | No |
Key Differentiators
- CAN-centric peripheral set for industrial networking (vs ATSAM3S4CA-CUR)
- Same-footprint flash upgrade path (vs ATSAM3A8CA-CU)
- Ethernet-ready sibling for networked variants (vs ATSAM3X4CA-CU)
Design Notes
The 100-TFBGA (9x9 mm) uses a 0.8 mm ball pitch, requiring controlled BGA fanout - typically via-in-pad or dog-bone escape routing on 4+ layer PCBs. Allocate dedicated power/ground balls to solid planes and place at least one 100 nF ceramic decoupling capacitor per supply ball group within 2-3 mm of the package, plus bulk 10 uF at the regulator output, per the SAM3X/SAM3A datasheet power-supply recommendations. Route CANH/CANL as a 120-ohm differential pair and keep SSC/I2S clock lines away from the CAN pair to limit crosstalk.
SAM3A and SAM3X devices are closely related but not bit-identical: peripheral allocation, USB capability, and some ball functions differ between the families. Do not assume a SAM3X binary or ballout mapping transfers directly to the ATSAM3A4CA-CU. Verify the exact ball map in the SAM3X/SAM3A datasheet ballout tables, confirm clock-tree settings (PLL multipliers targeting 84 MHz), and re-test the flash write timing when porting code that performs in-application programming on the dual 128KB banks.
Power the ATSAM3A4CA-CU from a single 3.3V rail within the 1.62V-3.6V range, sequenced so VDDCORE/VDDIO rise together as described in the datasheet power-management section. Estimated: at 84 MHz typical core current on SAM3-class parts (tens of mA, exact figure [DATA_NEEDED: typical supply current]), a small LDO such as a 3.3V/150 mA part is sufficient for the MCU alone; budget additional current for CAN transceivers (roughly 40-50 mA) and SD-card write bursts (up to 100-200 mA) when sizing the upstream buck converter.
Compliance Information
CU suffix denotes Microchip green package: RoHS compliant, halogen-free, lead-free. Mouser listing states BGA100 GREEN IND TEMP. REACH and conflict-minerals status not stated in provided data.
