ATSAM3U1CA-CU - 96MHz Cortex-M3 MCU 64KB Flash | Microchip
MPN: ATSAM3U1CA-CU ✓ Active| Qty | Unit Price | Extended |
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| 1 | $0 | $0.00 |
| 10 | $0 | $0.00 |
| 100 | $0 | $0.00 |
| 500 | $0 | $0.00 |
| 1,000 | $0 | $0.00 |
ATSAM3U1CA-CU Overview
A microcontroller (MCU) is a complete computing system on a single chip, integrating a processor core, program memory, data memory, and peripherals. The ATSAM3U1CA-CU belongs to the ARM Cortex-M3 family of 32-bit embedded processors, positioned within the broader hierarchy of microprocessors and system-on-chip (SoC) devices for power-management and embedded control applications.
Key features include the ARM Cortex-M3 revision 2.0 core with Memory Protection Unit (MPU) and Thumb-2 instruction set, high-speed USB connectivity with an integrated transceiver for fast data up/downloading, robust EMI tolerance, and plug-and-play high-speed serial communication. The 128-bit-wide flash access improves instruction fetch efficiency, and the device operates from a 1.62 V to 3.6 V single supply.
The SAM3U architecture emphasizes USB data throughput: the embedded high-speed USB device port (480 Mbps capable transceiver) offloads data transfers from the CPU, while DMA channels move data between peripherals and memory without core intervention. This makes the device well suited to bridge USB host systems with data-acquisition, storage, and communication peripherals.
Typical applications include USB data loggers and high-speed data acquisition systems, industrial communication gateways, embedded control panels, and consumer devices requiring fast USB file transfer with robust EMI performance.
Designers should note the 64 KB flash and 20 KB SRAM capacity limits when sizing applications; the pin-compatible ATSAM3U2CA-CU and ATSAM3U4CA-CU in the same 100-TFBGA package offer 128 KB and 256 KB flash respectively, providing an upgrade path without PCB changes.
This page synthesizes distributor inventory, drop-in alternatives, comparison tables, and practical design notes not found in the manufacturer datasheet.
Drop-in alternatives for ATSAM3U1CA-CU — 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 ATSAM3U1CA-CU (same form factor and footprint) — differing in Package, Flash Memory, RoHS Status, SRAM.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
ATSAM3U2CA-CU
✅ Drop-In ⚠️ 参数待验证📋 Reference alternative (not in catalog)
ATSAM3U4CA-CU
✅ Drop-In ⚠️ 参数待验证✓ In Stock
Contact for price
View Datasheet →ATSAM3U1CA-AU
✅ Drop-In ⚠️ 参数待验证✓ In Stock
$12.7 / Unit
View Datasheet →ATSAM3U1CA-CU Maximum Ratings & Electrical Characteristics
| Core Processor | ARM Cortex-M3 (revision 2.0) |
| Core Size | 32-bit |
| Maximum Clock Frequency | 96 MHz |
| Program Memory Size | 64 KB (64K x 8) |
| Program Memory Type | FLASH |
| RAM Size | 20 KB (20K x 8) |
| Supply Voltage Range | 1.62 V to 3.6 V |
| USB | High-speed USB device with integrated transceiver |
| Memory Protection Unit | Yes (MPU) |
| Instruction Set | Thumb-2 |
| Series | SAM3U |
| Package | 100-TFBGA (9 x 9 mm) |
| Mounting Type | Surface Mount |
| Number of Pins / Balls | 100 |
| EMI Performance | Robust EMI tolerance (per Atmel/Microchip product description) |
| RoHS Status | Compliant (per distributor listings) |
ATSAM3U1CA-CU 100-tfbga (9 x 9 mm) Pin Configuration Guide
Pin configuration for ATSAM3U1CA-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 ATSAM3U1CA-CU.
Refer to the datasheet for full pin configuration.
Typical Applications
ATSAM3U1CA-CU is suitable for 6 applications: High-Speed USB Data Loggers, Industrial Communication Gateways, Embedded Control Panels, Consumer Devices with USB File Transfer, EMI-Sensitive Measurement Equipment, USB Bridge and Programming Adapters.
High-Speed USB Data Loggers
The ATSAM3U1CA-CU fits USB data-logger designs because its integrated high-speed USB device transceiver (480 Mbps capable) transfers logged data to host PCs far faster than full-speed alternatives, without an external PHY. The 96 MHz Cortex-M3 core with DMA offloads transfer management, while the 64 KB flash stores the USB stack, file system, and acquisition firmware and 20 KB SRAM buffers sample streams. Used between sensor front-ends and a USB host, the device performs acquisition locally and streams or dumps data on connect. The trade-off: for continuous high-rate streaming, firmware must manage the 20 KB SRAM buffer carefully to avoid underflow at high sample rates.
Recommended
Industrial Communication Gateways
In industrial gateways, the ATSAM3U1CA-CU bridges USB hosts to serial field devices, leveraging the SAM3U family's plug-and-play high-speed serial support and robust EMI tolerance cited in the Atmel product description. The 96 MHz Cortex-M3 with MPU provides the deterministic performance and memory isolation needed for protocol conversion between USB and UART/SPI/I2C industrial buses. Its 1.62 V to 3.6 V supply range supports standard 3.3 V industrial logic levels. The MPU enables partitioning of safety-critical protocol stacks from the USB stack, improving fault containment in always-on installations where a USB crash must not interrupt field-side communication.
Recommended
Embedded Control Panels
For embedded control panels and HMI boards, the ATSAM3U1CA-CU offers a 96 MHz 32-bit core with sufficient performance for touch decoding, display refresh via serial interfaces, and USB configuration ports. The 64 KB flash accommodates a control application plus a USB device stack for firmware updates and configuration download, a core SAM3U use case (fast up/downloading of data). The 100-ball TFBGA's 9 x 9 mm footprint keeps board area small for compact panel designs. The Memory Protection Unit guards the UI task from USB-stack faults, improving field reliability in kiosk and machine-control environments where unattended operation is required.
Recommended
Consumer Devices with USB File Transfer
Consumer products that exchange files with PCs - media accessories, card readers, portable instruments - benefit from the ATSAM3U1CA-CU's integrated high-speed USB transceiver, which the Atmel datasheet highlights for fast up/downloading of data and plug-and-play operation. The 128-bit-wide flash architecture sustains efficient code execution at 96 MHz while USB transfers proceed via DMA. The 1.62 V to 3.6 V operating range and small 9 x 9 mm TFBGA suit battery-powered, space-constrained enclosures. Designers should budget the 20 KB SRAM between USB endpoints, file buffers, and application stacks, moving bulk data through DMA to SRAM in double-buffered blocks for sustained throughput.
Recommended
EMI-Sensitive Measurement Equipment
Bench instruments and measurement modules exploit the SAM3U family's documented robust EMI tolerance. The ATSAM3U1CA-CU's integrated USB transceiver avoids external PHY switching noise near sensitive analog front-ends, and the 1.62 V to 3.6 V supply allows clean, well-filtered low-voltage rails. The 96 MHz Cortex-M3 processes DSP-style filtering while DMA moves ADC samples; the MPU separates measurement firmware from the USB reporting stack. Designers should place the TFBGA over a solid ground plane and use Microchip's SAM3U reference-design decoupling pattern to preserve the EMI performance cited in the product description, particularly around the USB ball group.
Recommended
USB Bridge and Programming Adapters
Debug probes, ISP adapters, and USB-to-serial bridges use the ATSAM3U1CA-CU's defining strength: high-speed USB with an integrated transceiver for fast code download to target devices, as stated directly in the Atmel SAM3U product description. The 96 MHz core runs protocol layers while DMA sustains endpoint throughput; 64 KB flash holds the bridge firmware and descriptors, and 20 KB SRAM provides endpoint and pipe buffering. The 9 x 9 mm 100-TFBGA keeps adapter dongles compact. Design considerations include implementing the USB 2.0 compliance network on the DP/DM balls exactly per the datasheet reference design and reserving SRAM headroom for variable-length transfer buffers.
Recommended
Recommended Products Summary
Engineering reference data for ATSAM3U1CA-CU — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | ATSAM3U2CA-CU | ATSAM3U4CA-CU | ATSAM3U1CA-AU |
|---|---|---|---|---|
| Package | 100-TFBGA (9 x 9 mm) | 100-TFBGA (9 x 9 mm) - same | 100-TFBGA (9 x 9 mm) - same | 100-TFBGA (9 x 9 mm) - same (verify suffix ballout) |
| Brand | Microchip Technology (Atmel) | Microchip Technology (Atmel) | Microchip Technology (Atmel) | Microchip Technology (Atmel) |
| Core / Max Speed | ARM Cortex-M3, 96 MHz | ARM Cortex-M3, 96 MHz | ARM Cortex-M3, 96 MHz | ARM Cortex-M3, 96 MHz |
| Flash Memory | 64 KB | 128 KB (+100%) | 256 KB (+300%) | 64 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 |
| High-Speed USB | Yes (integrated transceiver) | Yes (integrated transceiver) | Yes (integrated transceiver) | Yes (integrated transceiver) |
Key Differentiators
- Lowest-memory (lowest-cost) 100-TFBGA SAM3U option (vs ATSAM3U2CA-CU)
- Upgrade path to 4x flash without PCB change (vs ATSAM3U4CA-CU)
- Integrated high-speed USB transceiver (vs ATSAM3N4BA-MU)
Design Notes
The 100-TFBGA (9 x 9 mm) with 0.8 mm ball pitch requires controlled-impedance layout for the high-speed USB balls. Route DP/DM as a 90-ohm differential pair with length matching within 0.5 mm, and place the USB compliance resistor network per the SAM3U datasheet reference design. Use a solid ground plane on the layer immediately beneath the BGA, with via-in-pad or dog-bone fanout and at least one decoupling capacitor per supply ball pair placed within 2 mm.
The device operates from 1.62 V to 3.6 V; use a low-noise LDO or well-filtered buck output. Add 100 nF ceramic decoupling at every VDD ball plus bulk 10 uF per supply domain. Estimated: at 96 MHz the SAM3U core current is on the order of tens of mA - verify the exact figure against the SAM3U datasheet power consumption chapter for your voltage and clock configuration rather than relying on this estimate.
A frequent SAM3U pitfall is underestimating the 64 KB flash budget: the high-speed USB device stack plus descriptors can consume a large fraction, leaving little for application code. If your compiled image exceeds roughly 48 KB, select the pin-compatible ATSAM3U2CA-CU (128 KB) or ATSAM3U4CA-CU (256 KB) instead - same 100-TFBGA footprint, no PCB change. Also confirm the lock-bit and boot-mode strap configuration before mass production to avoid bricking during field programming.
Compliance Information
RoHS compliance and lead-free status inferred from the 'CU' suffix designation in Atmel/Microchip ordering nomenclature per distributor listings. REACH, halogen-free, and conflict-minerals declarations not found in retrieved data - verify on Microchip's product compliance page.
