ATSAM3U1CB-CU - 96MHz Cortex-M3 MCU 64KB Flash | Microchip
MPN: ATSAM3U1CB-CU ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $7.94 | $7.94 |
| 10 | $7.3 | $73.00 |
| 100 | $6.8 | $680.00 |
| 500 | $6.4 | $3,200.00 |
| 1,000 | $5.95 | $5,950.00 |
ATSAM3U1CB-CU Overview
A microcontroller (MCU) is a single-chip embedded computer that integrates a processor core, nonvolatile flash memory for program storage, SRAM for data, and a rich set of peripherals on one die. Within the power-management hierarchy of embedded systems, an MCU sits at the application layer, coordinating sensors, communication interfaces, and actuators, and the SAM3U family belongs to the wider ARM Cortex-M class of 32-bit MCUs used across industrial and consumer electronics.
Key features include the Cortex-M3 revision 2.0 core with Thumb-2 instruction set and a Memory Protection Unit (MPU), a 128-bit-wide flash access interface with memory accelerator for deterministic execution at 96 MHz, and integrated 10-bit and 12-bit ADCs for precision analog acquisition. The SAM3U family uniquely integrates a high-speed USB device port, making it attractive for data-acquisition endpoints.
Architecturally, the flash memory uses a dual-bank structure with a memory accelerator that prefetches instructions to sustain zero-wait-state performance from the fast 128-bit bus, while the MPU supports safety-oriented software partitioning typical of Cortex-M3 designs.
Typical applications include USB data-logger and bridge devices, industrial sensing nodes exploiting the 12-bit ADC, and portable instruments where the compact 9x9 mm TFBGA conserves board area.
When designing with this part, budget the 64 KB flash carefully; if firmware grows, pin-compatible SAM3U family members with larger flash are available. Decouple each VDD ball with 100 nF ceramics placed close to the package.
This page synthesizes distributor pricing, drop-in family alternatives, and practical design notes not found in the manufacturer datasheet.
Drop-in alternatives for ATSAM3U1CB-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 ATSAM3U1CB-CU (same form factor and footprint) — differing in Flash Memory, SRAM, Core Processor, Core Size, Maximum Clock Frequency.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
ATSAM3U4CA-CU
✅ Drop-In✓ In Stock
Contact for price
View Datasheet →ATSAM3U2CA-CU
✅ Drop-In📋 Reference alternative (not in catalog)
ATSAM3U1CA-CU
✅ Drop-In ⚠️ 参数待验证✓ In Stock
Contact for price
View Datasheet →ATSAM4S2CB-CN
✅ Drop-In📋 Reference alternative (not in catalog)
ATSAM3S8BA-MUR
✅ Drop-In ⚠️ 参数待验证✓ In Stock
$5.15 / Unit
View Datasheet →ATSAM3U1CB-CU Maximum Ratings & Electrical Characteristics
| Core Processor | ARM Cortex-M3 (revision 2.0) |
| Core Size | 32-bit |
| Maximum Clock Frequency | 96 MHz |
| Flash Memory | 64 KB (64K x 8) |
| SRAM | 20 KB |
| Supply Voltage Range | 1.62 V to 3.6 V |
| Number of I/O | 57 |
| ADC Resolution | 10-bit, 12-bit |
| Operating Temperature | -40 C to +85 C |
| Package | 100-TFBGA (9x9 mm) |
| Mounting Type | Surface Mount |
| Memory Protection Unit | Yes (MPU) |
| Instruction Set | Thumb-2 |
| Flash Bus Width | 128-bit with memory accelerator, dual bank |
| Life Cycle Stage | ACTIVE |
| RoHS Status | Compliant (ROHS, per JLCPCB listing) |
| Internal Oscillators | 4, 8, 12 MHz, 32 kHz |
| UART | 4 |
ATSAM3U1CB-CU 100-tfbga (9x9 mm) Pin Configuration Guide
Pin configuration for ATSAM3U1CB-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 ATSAM3U1CB-CU.
Refer to the datasheet for full pin configuration.
Typical Applications
ATSAM3U1CB-CU is suitable for 6 applications: USB Data Logger, Industrial Sensor Node, Portable Instrumentation, USB Bridge / Converter, Consumer Embedded Control, Medical Sensor Acquisition Module.
USB Data Logger
The ATSAM3U1CB-CU fits USB data-logging endpoints because the SAM3U family integrates a high-speed USB device peripheral alongside a 96 MHz Cortex-M3 core, allowing sensor samples from the 12-bit ADC to be streamed to a host at USB speeds without an external USB bridge chip. The 128-bit wide flash interface with memory accelerator keeps code execution deterministic while interrupts service the USB stack, and the 20 KB SRAM provides room for double-buffering sample blocks. Firmware should be budgeted to the 64 KB flash limit; a simple acquisition-and-stream application with a CDC or MSC class stack fits comfortably. Supply the MCU from a 3.3 V rail within the 1.62 V to 3.6 V range and decouple VDDIO balls near the package.
Recommended
Industrial Sensor Node
Industrial sensing nodes benefit from the ATSAM3U1CB-CU combination of a 96 MHz Cortex-M3, integrated 10-bit and 12-bit ADCs, and four UARTs for MODBUS or RS-485 links through external transceivers. The -40 C to +85 C industrial temperature rating and 1.62 V to 3.6 V supply tolerance suit factory-floor power conditions, while the Memory Protection Unit supports partitioned, safety-conscious firmware structures. The 57 I/O lines drive local relays, indicators, and digital sensors directly. Because the internal 4/8/12 MHz and 32 kHz oscillators remove the need for precise external clocks in non-timing-critical nodes, BOM cost drops; only the ADC reference and any UART timing crystal require external precision. Sleep modes between samples stretch battery or energy-harvesting budgets.
Recommended
Portable Instrumentation
Handheld and portable instruments exploit the compact 9x9 mm 100-ball TFBGA of the ATSAM3U1CB-CU to pack a full 32-bit processing platform into minimal board area. The 12-bit ADC digitizes analog front ends directly at up to the converter's rated resolution, and the 96 MHz core executes DSP-style filtering on acquired data before display or USB transfer. Operating from a single Li-ion cell through a 3.3 V regulator fits the 1.62 V to 3.6 V input window. The internal 32 kHz oscillator keeps a real-time clock domain alive in backup between measurements. Designers should verify current draw per mode in the SAM3U datasheet electrical characteristics to size the battery for the required measurement duty cycle and standby life.
Recommended
USB Bridge / Converter
The ATSAM3U1CB-CU serves as a USB-to-UART/SPI/I2C bridge: the SAM3U high-speed USB device port connects to the host while four UARTs plus SPI and I2C peripherals talk to downstream devices, with the 96 MHz Cortex-M3 handling protocol translation in firmware. The Thumb-2 instruction set and memory accelerator keep interrupt latency low for time-critical serial timing, and 57 I/O lines expose optional control and status signals. Bridge firmware is compact and fits the 64 KB flash with margin. When full USB 2.0 high-speed throughput is required, confirm the SAM3U USB peripheral mode in the datasheet; for pure full-speed bridging the part operates comfortably within the 20 KB SRAM buffer budget.
Recommended
Consumer Embedded Control
Consumer products such as appliance controllers, small displays, and accessories use the ATSAM3U1CB-CU where a 32-bit platform with USB connectivity replaces legacy 8-bit designs. The RoHS-compliant green TFBGA package supports lead-free reflow assembly required for consumer manufacturing, and the 1.62 V to 3.6 V supply tolerates low-cost regulator ripple. The Cortex-M3 MPU allows isolating bootloader firmware from application code for field update safety, a capability consumer IoT platforms increasingly demand. At volume, the roughly $5.95 per 1000-unit tier (as of 2026-09-19) makes the 32-bit upgrade cost-neutral versus 8-bit solutions, while the SAM3U ecosystem (Atmel Studio 7, ASF3) shortens firmware development timelines considerably.
Recommended
Medical Sensor Acquisition Module
Non-diagnostic medical and wellness sensor modules leverage the ATSAM3U1CB-CU's 12-bit ADC for biopotential or physiological front ends, with the 96 MHz core performing digital filtering and the USB device port delivering data to host software. The wide 1.62 V to 3.6 V supply range permits operation directly from small Li-ion or coin cells through a low-noise LDO, and low-power sleep modes conserve battery between sampling windows. Note that this general-purpose MCU carries no medical qualification; system-level IEC 60601 compliance is the designer's responsibility. Verify ADC noise performance in the SAM3U datasheet against your signal-chain budget, and consider oversampling to extend effective resolution beyond 12 bits in quiet front-end designs.
Recommended
Recommended Products Summary
Engineering reference data for ATSAM3U1CB-CU — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | ATSAM3U4CA-CU | ATSAM3U2CA-CU | ATSAM3U1CA-CU | ATSAM4S2CB-CN | ATSAM3S8BA-MUR |
|---|---|---|---|---|---|---|
| Package | 100-TFBGA (9x9 mm) | 100-TFBGA - same footprint | 100-TFBGA - same footprint | 100-TFBGA - same footprint | 100-TFBGA - same pin count, verify ballout | 100-TFBGA - same footprint |
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Core | ARM Cortex-M3, 96 MHz | ARM Cortex-M3, 96 MHz | ARM Cortex-M3, 96 MHz | ARM Cortex-M3, 96 MHz | ARM Cortex-M4 (with FPU family option) | ARM Cortex-M3 |
| Supply Voltage Range | 1.62 V to 3.6 V | 1.62 V to 3.6 V (1.8 V/3.3 V typical) | 1.62 V to 3.6 V | 1.62 V to 3.6 V | up to 3.6 V max | 1.62 V to 3.6 V |
| High-Speed USB Device | Yes (SAM3U family feature) | Yes | Yes | Yes | FS USB device | No (SAM3S has no high-speed USB) |
| Lifecycle Status | ACTIVE | ACTIVE | ACTIVE | ACTIVE | ACTIVE | ACTIVE |
Key Differentiators
- Lowest flash / lowest cost point of the SAM3U TFBGA-100 family (vs ATSAM3U4CA-CU)
- High-speed USB device peripheral unique to the SAM3U line (vs ATSAM3S8BA-MUR)
- Simpler 64 KB BOM for cost-optimized builds (vs ATSAM3U2CA-CU)
- Mature Cortex-M3 with MPU and Thumb-2 at 96 MHz (vs ATSAM4S2CB-CN)
Design Notes
Power the ATSAM3U1CB-CU from a clean 3.3 V rail within its 1.62 V to 3.6 V range. Provide separate decoupling for VDDCORE/VDD and VDDIO per the SAM3U datasheet power distribution table: place one 100 nF ceramic directly at each supply ball pair plus one bulk 4.7-10 uF capacitor near the package. If USB is used, keep the USB ball traces short and impedance-controlled (90 ohm differential). Estimated: at 3.3 V and typical active current (see datasheet electrical characteristics for exact figures), a 500 mW dissipation budget is easily met by the 9x9 mm TFBGA without heatsinking.
The 100-ball TFBGA (9x9 mm, 0.8 mm ball pitch typical for this family) requires a fine-pitch SMT process. Use a 4-layer PCB with a dedicated ground plane: fan out the 57 GPIO balls on inner layers via via-in-pad or dog-bone escapes with 4/4 mil minimum trace/space. Place the 0.8 mm-pitch stencil apertures at 90-100% of ball diameter with a 130 um stencil for reliable solder volume. Verify ball A1 orientation marker against the SAM3U datasheet ballout diagram before layout sign-off - a rotated footprint is a common and costly error with BGA MCUs.
Flash budget is the most frequent pitfall: 64 KB must hold the application plus any USB stack. Enable compiler optimization (-Os) and verify flash usage at each release; if the image approaches 60 KB, plan migration to the pin-compatible ATSAM3U2CA-CU (128 KB) or ATSAM3U4CA-CU (256 KB) in the same TFBGA-100 footprint. Also note the MPU configuration: incorrectly sized MPU regions can fault at runtime on Cortex-M3. Program via the SAM-BA boot ROM or JTAG/SWD; reserve a 2x5 debug header on the PCB for factory programming.
Compliance Information
RoHS compliant per Mouser ('TFBGA, Grn') and JLCPCB (ROHS marking) listings. -CU suffix denotes Microchip green/RoHS package option. REACH, halogen-free, and conflict-minerals status not stated in provided data - confirm via Microchip product compliance documentation.
