ATSAM3S2BA-MUR - 64MHz Cortex-M3 MCU 128KB Flash | Microchip
MPN: ATSAM3S2BA-MUR ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $5.22 | $5.22 |
| 10 | $4.98 | $49.80 |
| 100 | $4.68 | $468.00 |
| 500 | $4.42 | $2,210.00 |
| 1,000 | $4.1 | $4,100.00 |
ATSAM3S2BA-MUR Overview
A microcontroller (MCU) is a single-chip integrated circuit that combines a processor core, program memory, data memory, and a rich set of peripherals into one package. Within the embedded-systems hierarchy, the SAM3S sits in the mid-range 32-bit MCU class, positioned above 8-bit PIC and AVR devices and below high-performance Cortex-M4/M7 families, targeting cost-sensitive applications that still require 32-bit compute throughput and USB connectivity.
Key features include the 64 MHz Cortex-M3 core with a 3-stage pipeline and Thumb-2 instruction set, 128 KB of self-programmable Flash with a dedicated flash controller, and an integrated USB 2.0 Full-Speed Device port. The device also integrates a 12-bit ADC with 16 channels, a 2-channel 12-bit DAC, a capacitive-touch support peripheral, PWM channels, USART/SPI/TWI serial interfaces, and an internal 1.8V/3.3V operating regime supplied from 1.62V to 3.6V.
Technically, the SAM3S implements Microchip (Atmel) SMART ARM-based architecture with a multi-layer bus matrix, DMA-capable peripheral event system, and power management controller offering sleep, wait, and backup modes with low quiescent consumption for battery-powered designs. The exposed-pad QFN package improves thermal dissipation and ground return paths for mixed-signal performance.
Typical applications include industrial control panels, consumer appliances, USB-connected sensors and dataloggers, and battery-powered metering products where the combination of Cortex-M3 performance, USB device connectivity, and integrated analog reduces total bill-of-materials cost.
For design, plan the VDDCORE/VDDIO decoupling network per the manufacturer datasheet and use the exposed pad as the main ground connection; flash wait-state configuration relative to the 64 MHz clock also affects efficiency.
This page synthesizes distributor pricing, drop-in same-family alternatives, and practical design notes not consolidated in the manufacturer datasheet.
Drop-in alternatives for ATSAM3S2BA-MUR — 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 ATSAM3S2BA-MUR (same form factor and footprint) — differing in RoHS Status, Core Processor, Maximum Clock Frequency, Supply Voltage Range, Flash Memory Size.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
ATSAM3S4BA-MUR
✅ Drop-In ⚠️ 参数待验证✓ In Stock
Contact for price
View Datasheet →ATSAM3S1BA-MUR
✅ Drop-In ⚠️ 参数待验证✓ In Stock
$3.35 / Unit
View Datasheet →ATSAM3S2AA-MUR
✅ Drop-In✓ In Stock
$3.49 / Unit
View Datasheet →ATSAM3N4BA-MU
✅ Drop-In✓ In Stock
$3.48 / Unit
View Datasheet →ATSAM3S2BA-AU
✅ Drop-In✓ In Stock
$4.66 / Unit
View Datasheet →ATSAM3S2BA-MUR Maximum Ratings & Electrical Characteristics
| Core Processor | ARM Cortex-M3 |
| Core Size | 32-Bit |
| Maximum Clock Frequency | 64 MHz |
| Flash Memory | 128 KB (128K x 8) |
| Supply Voltage Range | 1.62 V to 3.6 V (1.8V/3.3V operation) |
| Package | 64-QFN (9x9 mm) with Exposed Pad |
| Number of Pins | 64 |
| USB | USB 2.0 Full-Speed Device |
| ADC Resolution | 12-bit |
| DAC Resolution | 12-bit |
| Operating Temperature | -40C to +85C (Industrial) |
| Mounting Type | Surface Mount |
| Series | SAM3S |
| Peripherals | DMA, PWM, WDT, Capacitive Touch |
| Communication Interfaces | USART, SPI, TWI (I2C), USB |
| RoHS Status | Compliant (Green package per Mouser listing) |
ATSAM3S2BA-MUR 64-qfn (9x9 mm) with exposed pad Pin Configuration Guide
Pin configuration for ATSAM3S2BA-MUR (64-qfn (9x9 mm) with exposed pad 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 ATSAM3S2BA-MUR.
Refer to the datasheet for full pin configuration.
Typical Applications
ATSAM3S2BA-MUR is suitable for 6 applications: Industrial Control Panels, USB Sensors and Dataloggers, Battery-Powered Metering, Consumer Appliances, Medical Monitoring Devices, Capacitive Touch Human Interfaces.
Industrial Control Panels
The ATSAM3S2BA-MUR fits industrial control and HMI panel designs because its 64 MHz Cortex-M3 core delivers deterministic interrupt handling for real-time I/O scanning, while 128 KB Flash accommodates protocol stacks such as Modbus and firmware update code. The 12-bit ADC with 16 channels reads analog sensor inputs directly, and the capacitive-touch support enables modern buttonless front panels without dedicated touch controllers. Multiple USART, SPI, and TWI ports link the MCU to PLC expansion modules, displays, and actuators. Industrial -40C to +85C rating matches panel environments, and DMA channels offload serial transfers to keep CPU load low.
Recommended
USB Sensors and Dataloggers
The integrated USB 2.0 Full-Speed Device controller makes the ATSAM3S2BA-MUR a strong fit for USB-connected sensors and data loggers, since it removes the need for a separate USB interface chip and implements vendor-class or CDC-ACM virtual COM enumeration using the on-chip SAM-BA ROM bootloader for field firmware updates. The 12-bit ADC samples sensor channels at up to 2 Msps-class rates with DMA into 32 KB SRAM buffering, while low-power Wait modes conserve energy when running from an internal battery between USB sessions. Supply range of 1.62V to 3.6V supports bus-powered or battery-powered topologies.
Recommended
Battery-Powered Metering
Smart meters and sub-metering products benefit from the ATSAM3S2BA-MUR's combination of low-power operating modes and measurement peripherals. The power management controller provides Sleep, Wait, and Backup modes that cut average current to microamp levels between measurement intervals, critical for ten-year battery-life targets. The 12-bit ADC with 16 channels samples current and voltage channels, and RTC/RTT timers maintain timekeeping in Backup mode. The 64-pin QFN footprint integrates enough GPIO for LCD driver expansion and communication ports for RS-485 (USART) or IR interfaces, all within a single 3.3V rail.
Recommended
Consumer Appliances
White goods, small appliances, and climate-control products use the ATSAM3S2BA-MUR for motor control and user interface consolidation. PWM channels drive BLDC or brushed motor drivers, while the 12-bit ADC reads temperature sensors (NTC) and user controls, and the capacitive-touch capability implements sleek glass-panel interfaces without mechanical buttons. The 64 MHz Cortex-M3 handles control loops and UI rendering concurrently, and RoHS-compliant green packaging meets consumer environmental requirements. The 9x9 mm QFN exposed-pad package provides the thermal path needed near motor driver circuitry at moderate dissipation.
Recommended
Medical Monitoring Devices
Portable medical monitors such as pulse oximeters, blood-pressure units, and vitals dataloggers leverage the ATSAM3S2BA-MUR's low-noise 12-bit ADC and low-power profile. Battery operation from a 3.3V rail with Sleep/Wait modes extends usage between charges, while the USB Full-Speed Device port transfers recorded sessions to clinic PCs without proprietary cables. The Cortex-M3 core executes digital filtering and baseline algorithms on sampled data, and 128 KB Flash stores calibration tables plus logging firmware. The industrial temperature range and RoHS compliance align with typical medical-device component requirements for -40C to +85C transport environments.
Recommended
Capacitive Touch Human Interfaces
The ATSAM3S2BA-MUR integrates Microchip's peripheral touch controller support, enabling capacitive buttons, sliders, and wheels directly on the MCU using only PCB copper electrodes, which eliminates dedicated touch ICs and lowers BOM cost. Designers implement touch channels on the 16 ADC channels while simultaneously running display serial interfaces and motor or relay outputs on PWM/GPIO. Microchip's QTouch library provides auto-tuning against humidity and temperature drift, and 128 KB Flash holds both the touch tuning tables and the application. The 3.3V operation and 64-QFN package with exposed pad improve sensing stability via a low-impedance ground.
Recommended
Recommended Products Summary
Engineering reference data for ATSAM3S2BA-MUR — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | ATSAM3S4BA-MUR | ATSAM3S1BA-MUR | ATSAM3N4BA-MU | ATSAM3S2BA-AU |
|---|---|---|---|---|---|
| Package | 64-QFN (9x9 mm) EP | 64-QFN (9x9 mm) - same | 64-QFN (9x9 mm) - same | 64-QFN (9x9 mm) - same | LQFP64 - different package (die-equivalent) |
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Core / Speed | Cortex-M3, 64 MHz | Cortex-M3, 64 MHz | Cortex-M3, 64 MHz | Cortex-M3, 64 MHz | Cortex-M3, 64 MHz |
| Flash Memory | 128 KB | 256 KB | 64 KB | 128 KB | 128 KB |
| USB Device | Yes (Full-Speed) | Yes (Full-Speed) | Yes (Full-Speed) | No | Yes (Full-Speed) |
| 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 | 1.62 V to 3.6 V |
| Operating Temperature | -40C to +85C | -40C to +85C | -40C to +85C | -40C to +85C | -40C to +85C |
Key Differentiators
- Integrated USB Full-Speed Device controller (vs ATSAM3N4BA-MU)
- Balanced 128 KB Flash density (vs ATSAM3S4BA-MUR)
- Full analog integration (vs ATSAM3S1BA-MUR)
Design Notes
The 64-QFN (9x9 mm) exposed pad is the primary ground and thermal connection. Create a solder-mask-defined landing pad on the PCB with a via array (5x5 minimum, 0.3 mm vias) under the exposed pad to tie it to internal ground planes; this minimizes ground bounce for the 12-bit ADC and improves EMI. Follow the Microchip SAM3S hardware design application note for pad geometry and stencil aperture recommendations (typically 50-70% coverage).
The SAM3S integrates an internal regulator generating VDDCORE from the main supply; per the datasheet, decouple VDDCORE, VDDIO, VDDIN, and VDDUSB each with 100 nF ceramics placed within 2 mm of the pins, plus bulk capacitance per power domain. Because the device operates down to 1.62V, ensure the 3.3V rail stays above 1.9V under brownout to keep the internal regulator in specification, or configure the supply-monitor/brownout detector accordingly.
Flash wait states must be configured for the selected clock frequency; running the core at 64 MHz with incorrect flash wait states causes hard faults during code execution. Also, when using the USB Full-Speed port, the 480 MHz-class internal PLL must be configured to the exact 48 MHz USB clock requirement - use the PMC USB clock divider, not a fractional approximation. Finally, the SAM-BA bootloader only activates if the GPNVM boot-bit configuration allows it; erase-all can restore it if locked out.
Estimated: at 64 MHz active mode the SAM3S dissipates on the order of 100 mW (typical core current in the tens of mA at 3.3 V). With the exposed pad well soldered, junction rise is negligible (<5C) and no heatsinking is required. Concern only arises if high GPIO drive loads or external circuitry pull large currents through the package; in that case compute P_total = VDD x I_total and verify against theta_JA from the manufacturer datasheet.
Compliance Information
RoHS-compliant green QFN package per Mouser listing (QFN GREEN IND TEMP). REACH, halogen-free, and conflict-minerals status to be confirmed against Microchip material declarations.
