ATSAM3U4CA-CU - 96MHz Cortex-M3 MCU 256KB Flash | Microchip
MPN: ATSAM3U4CA-CU β Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $0 | $0.00 |
| 10 | $0 | $0.00 |
| 100 | $0 | $0.00 |
| 500 | $0 | $0.00 |
| 1,000 | $0 | $0.00 |
ATSAM3U4CA-CU Overview
A microcontroller unit (MCU) is a single-chip computer that integrates a processor core, memory, and peripherals on one die; the ATSAM3U4CA-CU sits in the hierarchy of ARM Cortex-M3 based Flash MCUs within the broader ARM microcontroller and power/embedded-processing ecosystem. The SAM3U family is positioned as a high-performance, high-integration USB-enabled MCU line for embedded systems.
Key features include the ARM Cortex-M3 revision 2.0 core running to 96 MHz with the Thumb-2 instruction set, a Memory Protection Unit (MPU), 128-bit wide Flash access with a memory accelerator for zero-wait-state execution at full speed, and dual-bank Flash (2 x 128 KB) enabling safe in-application programming and firmware upgrade. Per supply voltage options of 1.8V, 2.5V, or 3.3V, the device suits both battery-powered and rail-powered designs.
Technically, the ATSAM3U4CA-CU combines the Cortex-M3 RISC pipeline with high-bandwidth memory access. The 128-bit wide Flash interface plus accelerator mitigates the classic flash-latency bottleneck of fast MCUs, while the dual-bank architecture allows code to execute from one bank while the other is erased or programmed. The MPU supports functional-safety-oriented software partitioning. The SAM3U series is also known for its High Speed USB Device port and embedded Flash of up to 256 Kbytes with up to 52 Kbytes of SRAM.
Typical applications include USB device peripherals such as mass-storage and communication-class devices, industrial control nodes, and consumer embedded systems requiring 96 MHz-class processing with on-chip Flash.
Design consideration: the TFBGA (9x9) ball-grid package requires controlled-impedance, ball-escape-routing PCB design and reflow assembly; budget decoupling on all supply balls and follow the manufacturer layout guidance for the 100-ball footprint.
This page synthesizes verified distributor data, drop-in alternatives, pricing context, and practical design notes not consolidated in the manufacturer datasheet.
Drop-in alternatives for ATSAM3U4CA-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 ATSAM3U4CA-CU (same form factor and footprint) β differing in SRAM, Core Processor, Package, Flash Memory, Number of I/O.
Quick Comparison Tool β Select alternative parts for side-by-side comparison:
ATSAM3U2CA-CU
β Drop-In β οΈ εζ°εΎ ιͺθ―π Reference alternative (not in catalog)
ATSAM3U4EA-CU
β Drop-In β οΈ εζ°εΎ ιͺθ―π Reference alternative (not in catalog)
ATSAM3U4CA-CU Maximum Ratings & Electrical Characteristics
| Core Processor | ARM Cortex-M3 (revision 2.0) |
| Core Size | 32-bit |
| Maximum Clock Frequency | 96 MHz |
| Flash Memory | 256 KB (256K x 8), dual bank (2 x 128 KB) |
| SRAM | 52 KB |
| Instruction Set | Thumb-2 |
| Memory Protection | Memory Protection Unit (MPU) |
| Flash Access Width | 128-bit wide access with memory accelerator |
| Supply Voltage Options | 1.8V / 2.5V / 3.3V |
| Series | SAM3U |
| Package | 100-TFBGA (9x9 mm) |
| Mounting Type | Surface Mount |
| Lifecycle Status | ACTIVE |
| Packaging | Tray |
| Peripheral Highlights | High Speed USB Device, up to 52 KB SRAM |
ATSAM3U4CA-CU 100-tfbga (9x9 mm) Pin Configuration Guide
Pin configuration for ATSAM3U4CA-CU (100-tfbga (9x9 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 ATSAM3U4CA-CU.
Refer to the datasheet for full pin configuration.
Typical Applications
ATSAM3U4CA-CU is suitable for 6 applications: High Speed USB Device Peripherals, Industrial Control and Automation Nodes, Battery-Powered Portable Instruments, Embedded Firmware Upgrade Systems, Consumer Embedded Devices with USB Connectivity, Test and Measurement Instrumentation.
High Speed USB Device Peripherals
The ATSAM3U4CA-CU fits USB device designs because the SAM3U series integrates a High Speed USB Device peripheral on the 96 MHz Cortex-M3 platform. In a typical USB mass-storage or communication-device-class product, the MCU enumerates at high speed while the 128-bit wide Flash accelerator sustains firmware execution without stalling USB interrupts. The dual-bank Flash (2 x 128 KB) is a key benefit: firmware can run from one bank while the other is reprogrammed, enabling field USB firmware updates. Designs should budget the 52 KB SRAM across endpoint buffers, DMA descriptors, and the application stack. The 9x9 mm TFBGA-100 keeps the PCB area small for dongle-style products.
Recommended
Industrial Control and Automation Nodes
In industrial control nodes, the ATSAM3U4CA-CU provides 96 MHz Cortex-M3 throughput with a Memory Protection Unit (MPU) that lets firmware partition safety-critical tasks from application code. The 1.8V/2.5V/3.3V supply flexibility allows direct integration with 3.3V sensor buses or low-voltage analog front ends. The dual-bank Flash supports dependable in-field firmware upgrades on machines that cannot tolerate failed updates - one bank is validated before switching. The 52 KB SRAM handles communication buffers for fieldbus stacks. Engineers should account for the TFBGA package's reflow assembly requirements and follow Microchip layout guidance for supply decoupling on the 100-ball footprint in electrically noisy cabinets.
Recommended
Battery-Powered Portable Instruments
For battery-powered instruments, the ATSAM3U4CA-CU offers a 1.8V low-voltage operating option that reduces dynamic power at the same 96 MHz clock, and the Cortex-M3 architecture provides low-latency interrupt handling for duty-cycled measurement loops. The 256 KB dual-bank Flash stores logging firmware plus a bootloader, and 52 KB SRAM buffers sampled data between radio or USB transfers. Because the memory accelerator permits fast execution from Flash, external RAM or parallel Flash - which add quiescent cost - are unnecessary. Designers should verify sleep-mode currents in the official datasheet and gate unused peripheral clocks, as the SAM3U peripheral bus allows fine-grained clock disable per module.
Recommended
Embedded Firmware Upgrade Systems
The ATSAM3U4CA-CU is particularly appropriate for products that must be safely reprogrammed in the field. Its 2 x 128 KB dual-bank Flash means the bootloader writes and verifies the inactive bank while the application continues running at full 96 MHz speed from the active bank; only after a successful image check is the bank switched. This eliminates the classic brick risk of single-bank self-programming schemes. The 52 KB SRAM is ample for staging image blocks received over USB or UART. Combined with the Thumb-2 instruction set and memory accelerator, the device sustains full performance during update windows, an important differentiator versus smaller single-bank Cortex-M0/M0+ MCUs.
Recommended
Consumer Embedded Devices with USB Connectivity
Consumer products such as set-top accessories, gaming peripherals, and USB-connected display modules benefit from the ATSAM3U4CA-CU combination of High Speed USB Device throughput and a 9x9 mm TFBGA-100 footprint that supports compact two-sided PCB layouts. The 96 MHz Cortex-M3 with memory accelerator processes audio or data streams without external memory, while 256 KB Flash holds the USB class stack plus product firmware with headroom for features. The 3.3V supply option integrates directly with common consumer logic rails. The active lifecycle status and Microchip continuity make it viable for multi-year consumer product roadmaps where sourcing stability matters.
Recommended
Test and Measurement Instrumentation
Bench instruments and handheld meters use the ATSAM3U4CA-CU for its deterministic Cortex-M3 interrupt latency, MPU for isolating measurement firmware, and USB device port for PC connectivity and data upload. The 128-bit wide Flash access keeps the 96 MHz core fed during peak processing of sample streams into the 52 KB SRAM buffer. Dual-bank Flash allows an instrument vendor to add measurement firmware features over USB in the field. When laying out the analog front end, keep the TFBGA supply balls well decoupled and separate analog and digital returns per the manufacturer datasheet recommendations to preserve measurement resolution.
Recommended
Recommended Products Summary
Engineering reference data for ATSAM3U4CA-CU β comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | ATSAM3U2CA-CU | ATSAM3U4EA-CU | STM32F207 (series) | LPC1769 | TM4C123GH6PGE |
|---|---|---|---|---|---|---|
| Brand | Microchip Technology (Atmel) | Microchip Technology | Microchip Technology | STMicroelectronics | NXP Semiconductors | Texas Instruments |
| Drop-in / Pin Compatibility | Reference part | Same TFBGA100 SAM3U footprint | Same TFBGA100 SAM3U footprint | Functional equivalent only - not verified pin-to-pin | Functional equivalent only - not verified pin-to-pin | Functional equivalent only - not verified pin-to-pin |
Key Differentiators
- High Speed USB Device peripheral (vs ATSAM3N4CA-CU)
- Dual-bank 256 KB Flash for safe field updates (vs ATSAM3U2CA-CU)
- 128-bit wide Flash access with memory accelerator (vs Generic 32-bit-wide Flash MCUs)
Design Notes
The 100-TFBGA 9x9 mm package uses fine-pitch balls that require via-in-pad or dog-bone escape routing on standard PCB technology. Plan at least a 4-layer stackup with dedicated ground plane under the device, and place 100 nF ceramic decoupling capacitors on each supply ball pair as close to the package as possible. Verify the land pattern against the latest Microchip package drawing before releasing the PCB, as ball map revisions occur within a family.
The ATSAM3U4CA-CU supports 1.8V, 2.5V, or 3.3V configurations per distributor data. Confirm from the official datasheet which balls carry VDDCORE/VDDIO and whether external regulation or internal regulator mode is used for your voltage choice. Estimated: dynamic power scales roughly with V^2 x f, so selecting 1.8V instead of 3.3V on battery designs can reduce core dynamic consumption by roughly 70% at the same 96 MHz clock, subject to datasheet-confirmed operating limits.
Do not treat cross-brand 'equivalents' (STM32F207, LPC1769, TM4C123GH6PGE per etei.com) as pin-to-pin drop-ins - they are functional alternatives with different ball maps and peripheral sets, and a PCB redesign is required. Within the SAM3U family, the ATSAM3U2CA-CU shares the TFBGA100 footprint but halves Flash to 128 KB, so verify your image size before swapping. Always validate startup code and clock configuration against the specific SAM3U device ID during firmware migration.
Compliance Information
Compliance status not stated in the verified web data; confirm RoHS/REACH status on the Microchip product page or distributor environmental datasheets before procurement.
