ATSAM3U1EB-CU - 96MHz Cortex-M3 MCU 64KB Flash | Microchip
MPN: ATSAM3U1EB-CU β Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $5.99 | $5.99 |
| 10 | $5.49 | $54.90 |
| 100 | $5.19 | $519.00 |
| 500 | $4.89 | $2,445.00 |
| 1,000 | $4.59 | $4,590.00 |
ATSAM3U1EB-CU Overview
A microcontroller (MCU) is a single integrated circuit that combines a processor core, memory, and peripherals into one chip, forming the lowest tier of the embedded-computing hierarchy: MCU -> microcontroller unit -> embedded processor -> semiconductor. The SAM3U series targets high-pin-count, high-speed embedded applications where a 32-bit core outperforms 8-bit and 16-bit MCUs.
Key features include the ARM Cortex-M3 revision 2.0 core with Thumb-2 instruction set for high code density, a Memory Protection Unit (MPU) for robust task isolation, and a 128-bit-wide flash access interface with a memory accelerator that sustains near-zero-wait-state execution at 96 MHz. The dual-bank flash architecture enables safe in-application programming and firmware updates.
The SAM3U family is distinguished by an integrated high-speed USB Device port and a UART capable of up to 12 Mbps, making it well suited to communication-intensive designs. The SAM3U1EB variant provides 64 KB of flash in the same pinout as larger 256 KB siblings, allowing flash-size migration without PCB changes.
Typical applications include USB-enabled industrial devices, data-logging equipment, gateways, and consumer electronics requiring a 32-bit core with flexible I/O on a 144-ball footprint.
When designing, keep the 1.62V to 3.6V supply range in mind for battery or mixed-rail systems, and plan the BGA fanout and decoupling layout early, since 144-ball packages demand careful power-plane design.
This page synthesizes distributor pricing, drop-in alternatives, comparison data, and practical design notes not found in the manufacturer datasheet alone.
Drop-in alternatives for ATSAM3U1EB-CU β same package, pin-to-pin compatible. Different-package parts requiring PCB rework are excluded.
Quick Comparison Tool β Select alternative parts for side-by-side comparison:
ATSAM3U1EA-CU
β Drop-In β οΈ εζ°εΎ ιͺθ―π Reference alternative (not in catalog)
ATSAM3U2EA-CU
β Drop-In β οΈ εζ°εΎ ιͺθ―π Reference alternative (not in catalog)
ATSAM3U2EB-CU
β Drop-In β οΈ εζ°εΎ ιͺθ―π Reference alternative (not in catalog)
ATSAM3U4EA-CU
β Drop-Inπ Reference alternative (not in catalog)
ATSAM3U4EB-CU
β Drop-In β οΈ εζ°εΎ ιͺθ―π Reference alternative (not in catalog)
ATSAM3U1EB-CU Maximum Ratings & Electrical Characteristics
| Core Processor | ARM Cortex-M3 revision 2.0 |
| Core Size | 32-bit |
| Maximum Clock Speed | 96 MHz |
| Flash Memory | 64 KB (64K x 8) |
| RAM Size | 20K x 8 |
| Supply Voltage Range | 1.62 V to 3.6 V |
| Memory Protection Unit | Yes (MPU) |
| Instruction Set | Thumb-2 |
| Flash Access | 128-bit wide, memory accelerator, dual bank |
| Package | 144-LFBGA (13x13 mm) |
| Number of Terminals | 144 |
| Terminal Form | Ball |
| Mounting Type | Surface Mount |
| Temperature Grade | Industrial |
| Life Cycle Stage | Active |
ATSAM3U1EB-CU 144-lfbga (13x13 mm) Pin Configuration Guide
Pin configuration for ATSAM3U1EB-CU (144-lfbga (13x13 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 ATSAM3U1EB-CU.
Refer to the datasheet for full pin configuration.
Typical Applications
ATSAM3U1EB-CU is suitable for 6 applications: USB Industrial Devices, Data Logging and Gateways, Communication Interfaces, Consumer Electronics Control, Embedded Systems Education and Prototyping, Security and Access Control Terminals.
USB Industrial Devices
The ATSAM3U1EB-CU fits USB-connected industrial equipment because the SAM3U family integrates a high-speed USB Device peripheral on-chip, eliminating an external USB controller. The 96 MHz ARM Cortex-M3 core with 128-bit-wide flash access sustains the interrupt and data movement workload of USB transfers, while the industrial temperature grade suits factory-floor environments. Deployed as the main controller of a USB instrument or actuator, the device handles enumeration, bulk transfers, and local control logic in one chip. The 1.62V to 3.6V supply range allows operation from standard 3.3V industrial rails, and the 144-ball LFBGA package provides enough I/O to interface sensors, displays, and control outputs alongside the USB link.
Recommended
Data Logging and Gateways
For data-logging nodes and protocol gateways, the ATSAM3U1EB-CU offers a 32-bit core at 96 MHz with 20 KB of SRAM for buffering sampled data before writing to external memory or forwarding over a communication link. The dual-bank flash architecture with 128-bit-wide access enables safe in-field firmware updates - a key requirement for deployed loggers that cannot be physically reprogrammed. The 64 KB flash stores protocol stacks plus logging firmware compactly thanks to Thumb-2 code density, and the Memory Protection Unit isolates critical logging routines from application code. Industrial temperature grading and the 1.62V to 3.6V supply range support battery-backed and unattended installations.
Recommended
Communication Interfaces
The SAM3U family distinguishes itself with a UART capable of very high serial throughput alongside the high-speed USB Device port, making the ATSAM3U1EB-CU a strong fit for bridge and interface-conversion products. Typical uses include USB-to-serial adapters, protocol converters, and sensor-hub controllers that aggregate multiple lower-speed links into a single high-speed upstream connection. The 96 MHz Cortex-M3 core handles framing, checksums, and buffering without host intervention, and the 144-ball package exposes enough I/O for multi-channel serial routing. Because the E-suffix 144-ball footprint is shared across the SAM3U family, interface designs can migrate to 128 KB or 256 KB flash variants (ATSAM3U2EB-CU, ATSAM3U4EA-CU) if protocol stacks grow.
Recommended
Consumer Electronics Control
In consumer products such as remote controls, appliance controllers, and small display drivers, the ATSAM3U1EB-CU provides 32-bit processing headroom at a mid-range price point of roughly $5.99 (as of 2026-09-19). The Thumb-2 instruction set keeps the 64 KB flash sufficient for GUI-lite and control firmware, while the Memory Protection Unit adds software robustness valued in devices with network-connected features. The 144-ball LFBGA offers abundant GPIO for keypads, indicators, and peripheral interfaces in a compact 13x13 mm footprint suitable for dense consumer PCBs. The 1.62V to 3.6V input range tolerates battery droop in portable designs, and active lifecycle status from Microchip supports continued production sourcing.
Recommended
Embedded Systems Education and Prototyping
The ATSAM3U1EB-CU serves embedded-systems coursework and prototyping platforms because it exposes a full-featured ARM Cortex-M3 with MPU, dual-bank flash, and rich peripherals in a documented, widely available 144-ball package. Students and engineers can exercise the 128-bit-wide flash accelerator, interrupt latency behavior, and memory-protection regions on real silicon, using the publicly available 'AT91SAM ARM-based Flash MCU' datasheet from Atmel/Microchip. The active lifecycle status and multi-distributor stock (2,464+ pieces at a single distributor as of 2026-09-19) make it practical to source for lab batches. Prototype boards can later migrate firmware unchanged to larger SAM3U variants when projects scale.
Recommended
Security and Access Control Terminals
Access-control terminals, card readers, and small security panels benefit from the ATSAM3U1EB-CU's combination of a 96 MHz Cortex-M3 core for authentication processing and USB Device connectivity for provisioning and log extraction. The Memory Protection Unit helps isolate credential-handling firmware from less-trusted application code, supporting basic defensive partitioning at the MCU level. With 64 KB flash and 20 KB SRAM, credential tables and audit buffers fit within on-chip memory for small installations, and the 144-ball package supplies the I/O for keypads, readers, relays, and tamper switches. Industrial temperature grading ensures dependable operation in outdoor and unconditioned enclosures across the part's 1.62V to 3.6V supply window.
Recommended
Recommended Products Summary
Engineering reference data for ATSAM3U1EB-CU β comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | ATSAM3U1EA-CU | ATSAM3U2EA-CU | ATSAM3U4EA-CU |
|---|---|---|---|---|
| Package | 144-LFBGA (13x13) | 144-LFBGA (13x13) - same | 144-LFBGA (13x13) - same | 144-BGA (13x13) - same |
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Core | ARM Cortex-M3 rev 2.0, 32-bit | ARM Cortex-M3, 32-bit | ARM Cortex-M3, 32-bit | ARM Cortex-M3, 32-bit |
| Maximum Clock Speed | 96 MHz | 96 MHz | 96 MHz | 96 MHz |
| Flash Memory | 64 KB | 64 KB | 128 KB | 256 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 |
Key Differentiators
- Lowest flash capacity in the pin-compatible SAM3U1E E-suffix footprint (vs ATSAM3U4EA-CU)
- Dual-bank 128-bit-wide flash with memory accelerator (vs Generic Cortex-M3 MCUs (e.g. AT32UC3A364-CTUR))
- Memory Protection Unit (MPU) on a cost-optimized MCU (vs ATSAM3U1EA-CU)
Design Notes
The 144-ball LFBGA at 13x13 mm requires a planned BGA fanout strategy before routing. Use an inner-layer via-in-pad or dog-bone escape pattern, and dedicate a solid ground plane directly under the ball field for return paths. Place at least one 100 nF decoupling capacitor per supply ball pair as close to the package as possible, plus bulk capacitance at the board entry. Verify the ball map against the manufacturer datasheet for your exact SAM3U1E variant, since peripheral configuration differs between the EA and EB suffixes.
Design the supply for the 1.62V to 3.6V operating window with margin: a 3.3V rail should regulate to no more than 3.6V under all transient conditions, and brownout behavior near 1.62V must be characterized. If the design uses a switching pre-regulator, follow it with a low-noise LDO for the analog and PLL supplies to protect clock jitter. Use the MCU power-management modes and confirm the current budget per active frequency point using the datasheet electrical characteristics tables rather than assuming worst-case numbers.
Do not assume the ATSAM3U1EA-CU and ATSAM3U1EB-CU are fully interchangeable: the suffix denotes different peripheral configurations even though pinout, package, flash, and core are identical. Always re-verify the peripheral set (USB, UART speed options, peripheral count) in the SAM3U family datasheet before a substitution. Additionally, dual-bank flash field-update code must erase only the inactive bank; writing the executing bank will stall or corrupt the core. Validate the MPU configuration early, since MPU faults discovered late in firmware development are costly to restructure.
Compliance Information
Jotrin lists the package as 'LFBGA, Grn' suggesting a green (halogen-free) package, but official RoHS/REACH declarations were not present in the provided data. Verify compliance on the official Microchip product page before release.
