ATSAM4S2BA-MU - 120MHz Cortex-M4 MCU, 128KB Flash | Microchip
MPN: ATSAM4S2BA-MU ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $5.2 | $5.20 |
| 10 | $4.7 | $47.00 |
| 100 | $4.15 | $415.00 |
| 500 | $3.75 | $1,875.00 |
| 1,000 | $3.35 | $3,350.00 |
ATSAM4S2BA-MU Overview
A microcontroller (MCU) is a single-chip embedded computer that integrates a processor core, non-volatile program memory, RAM, and a rich set of peripherals on one die. Within the hierarchy of embedded processors, the SAM4S sits between entry-level Cortex-M0+/M3 MCUs and high-performance Cortex-M7 devices, making it a general-purpose workhorse for industrial control and consumer products.
Key features include the Cortex-M4 core with DSP instructions and a hardware floating-point unit (FPU) for efficient single-precision math, a maximum operating frequency of 120 MHz, and low-power operation of 180 uA/MHz as cited on the Microchip product page. The supply range of 1.62V to 3.6V supports both 3.3V industrial rails and battery operation. Peripheral set of the SAM4S family typically includes USB 2.0 device, multiple USARTs, SPI, TWI (I2C), an ADC, and a PWM controller.
Technically, the SAM4S implements an ARMv7E-M architecture with Harvard bus structure, a multi-layer bus matrix, and flash accelerators that keep the core fed at 120 MHz from zero-wait-state flash bursts. Per the Microchip SAM4S family datasheet (document 60001419B), the series is pin-to-pin compatible with SAM4N, SAM3S, SAM3N, and legacy SAM7S devices in the 64-pin version, enabling easy in-portfolio migration.
Typical applications include industrial automation nodes, motor control and PWM-driven power stages, metering systems, USB-attached accessories, and IoT sensor gateways. The 120 MHz core with FPU suits control loops and digital filtering in compact designs.
A key design consideration: connect all VDDIO/VDDCORE and GND pins, and decouple each supply pin with 100 nF ceramics close to the exposed pad, which doubles as the thermal and ground anchor.
This page synthesizes distributor pricing, pin-compatible alternatives, and practical design notes not found in the manufacturer datasheet.
Drop-in alternatives for ATSAM4S2BA-MU — 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 ATSAM4S2BA-MU (same form factor and footprint) — differing in RoHS Status, Package, Core Processor, Operating Temperature, SRAM.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
ATSAM4S4BA-MU
✅ Drop-In ⚠️ 参数待验证📋 Reference alternative (not in catalog)
ATSAM4S8BA-MU
✅ Drop-In ⚠️ 参数待验证✓ In Stock
$5.79 / Unit
View Datasheet →ATSAM4SD32BA-MU
✅ Drop-In ⚠️ 参数待验证✓ In Stock
$7.85 / Unit
View Datasheet →ATSAM3S8BA-MUR
✅ Drop-In✓ In Stock
$5.15 / Unit
View Datasheet →ATSAM3N4BA-MU
✅ Drop-In✓ In Stock
$3.48 / Unit
View Datasheet →ATSAM4S2BA-MU Maximum Ratings & Electrical Characteristics
| Core Processor | ARM Cortex-M4 with FPU |
| Core Size | 32-bit |
| Maximum Clock Frequency | 120 MHz |
| Flash Memory | 128 KB (128K x 8) |
| SRAM | 64 KB |
| Supply Voltage Range | 1.62 V to 3.6 V |
| Supply Voltage | 1.2 V (core) / 3.3 V (I/O) |
| Package | 64-QFN (9x9 mm) with exposed pad |
| Mounting Type | Surface Mount |
| Operating Temperature | -40C to +85C (industrial) |
| Series | SAM4S |
| DSP Instructions | Yes |
| FPU | Yes (single precision) |
| Power Consumption | 180 uA/MHz (per Microchip product page) |
| RoHS Status | Compliant (green, MRL A per Mouser listing) |
ATSAM4S2BA-MU 64-qfn (9x9 mm) with exposed pad Pin Configuration Guide
Pin configuration for ATSAM4S2BA-MU (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 ATSAM4S2BA-MU.
Refer to the datasheet for full pin configuration.
Typical Applications
ATSAM4S2BA-MU is suitable for 6 applications: Industrial Automation Nodes, Motor Control and Drives, USB Accessories and Peripherals, Smart Metering, IoT Sensor Gateways, Consumer and Building Controls.
Industrial Automation Nodes
The ATSAM4S2BA-MU fits factory automation nodes such as I/O modules, sensor concentrators, and actuator controllers because its 120 MHz Cortex-M4 core with FPU handles real-time control loops while USART, SPI, and TWI peripherals link field devices. Operating from a 1.62V-3.6V supply at industrial -40C to +85C, it mounts directly on DIN-rail modules using the 64-QFN 9x9 mm footprint. Its 180 uA/MHz efficiency also suits always-on monitoring nodes. Firmware upgrades are supported through the SAM4S flash controller, and pin compatibility with SAM3S/SAM3N lets one PCB platform span cost- and performance-optimized variants across a product family.
Recommended
Motor Control and Drives
The SAM4S PWM controller and ADC make the ATSAM4S2BA-MU well suited for BLDC and PMSM motor control. The Cortex-M4 DSP instruction set plus single-precision FPU executes field-oriented control transforms and PI current loops efficiently at 120 MHz, while hardware PWM channels gate the inverter stage with microsecond resolution. Running a 20 kHz current loop consumes only a fraction of the CPU budget, leaving headroom for communication and supervisory logic. The industrial temperature rating covers drive enclosures, and the exposed-pad QFN grounds and cools the device when soldered to a drive PCB ground pour.
Recommended
USB Accessories and Peripherals
SAM4S devices integrate a USB 2.0 full-speed device port, letting the ATSAM4S2BA-MU serve as the main controller of USB keyboards, scanners, test-gadgets, and data loggers. The 120 MHz core sustains bulk-transfer rates and HID processing simultaneously, and 64 KB SRAM buffers endpoint data. Microchip provides the USB Device Stack within its ASF software framework, reducing firmware development effort. Because the supply range accepts USB 5V through a simple 3.3V regulator, bus-powered designs are straightforward, and the 64-QFN footprint keeps accessory PCBs compact for consumer enclosures.
Recommended
Smart Metering
Metering designs benefit from the ATSAM4S2BA-MU's combination of ADC, low 180 uA/MHz active power, and rich serial peripherals for communication with metering front-ends. The 120 MHz Cortex-M4 with FPU performs RMS energy calculations, digital filtering, and tamper detection in real time, while 128 KB flash stores application firmware plus calibration tables in the 64-QFN 9x9 mm footprint. Industrial temperature operation covers outdoor meter cabinets, and pin-compatible migration to ATSAM4S4BA-MU provides room for expanded communication stacks (DLMS/PRIME) without redesigning the PCB.
Recommended
IoT Sensor Gateways
As a gateway controller, the ATSAM4S2BA-MU aggregates sensor data over SPI/UART links and forwards it via external radio modules. The 120 MHz Cortex-M4 with hardware FPU runs sensor fusion and protocol stacks concurrently, while 64 KB SRAM holds message queues. Sleep modes on the SAM4S family allow battery-backed nodes to drop to microamp-level standby, and wake-on-interrupt pins react to sensor events. The industrial temperature range and 3.3V operation match common LoRa and Wi-Fi module supplies, and the exposed-pad QFN simplifies grounding for RF-module coexistence on compact gateway boards.
Recommended
Consumer and Building Controls
Thermostats, lighting controllers, appliance panels, and access-control readers use the ATSAM4S2BA-MU to combine HMI (touch/segment LCD via GPIO or external driver), control logic, and connectivity in one chip. The 120 MHz core provides responsiveness for capacitive-touch processing and display updates, while PWM outputs drive backlighting and triac/relay control stages. The 1.62V-3.6V supply allows direct 3.3V operation from appliance rails, and the 64-QFN package supports compact, cost-sensitive PCBs. Pin compatibility with SAM3N parts enables a low-cost variant on the identical board for entry SKUs.
Recommended
Recommended Products Summary
Engineering reference data for ATSAM4S2BA-MU — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | ATSAM4S4BA-MU | ATSAM4S8BA-MU | ATSAM4SD32BA-MU | ATSAM3S8BA-MU | ATSAM3N4BA-MU |
|---|---|---|---|---|---|---|
| Package | 64-QFN (9x9 mm) EP | 64-QFN (9x9 mm) - same | 64-QFN (9x9 mm) - same | 64-QFN (9x9 mm) - same | 64-QFN (9x9 mm) - same | 64-QFN (9x9 mm) - same |
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Core | ARM Cortex-M4 with FPU | ARM Cortex-M4 with FPU | ARM Cortex-M4 with FPU | ARM Cortex-M4 with FPU (dual-bank) | ARM Cortex-M3 (no FPU) | ARM Cortex-M3 (no FPU) |
| Max Clock Frequency | 120 MHz | 120 MHz | 120 MHz | 120 MHz | 96 MHz | 96 MHz |
| Flash | 128 KB | 512 KB | 1024 KB | 512 KB (2x256 KB dual bank) | 256 KB | 256 KB |
| SRAM | 64 KB | 128 KB | 128 KB | 128 KB | 64 KB | 32 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 | 1.62 V to 3.6 V | 1.62 V to 3.6 V |
| FPU | Yes (single precision) | Yes | Yes | Yes | No | No |
Key Differentiators
- Lowest memory in the pin-compatible SAM4S 64-QFN family (vs ATSAM4S4BA-MU)
- Cortex-M4 with FPU vs Cortex-M3 alternatives (vs ATSAM3S8BA-MU)
- Full SAM4S peripheral integration vs SAM3N alternative (vs ATSAM3N4BA-MU)
Design Notes
Power the ATSAM4S2BA-MU from a clean 3.3V rail within its 1.62V-3.6V range. The VDDCORE domain is generated internally but requires the datasheet-specified decoupling capacitor placed within 2 mm of the pin. Decouple every VDDIO pin with 100 nF X7R ceramics plus one bulk 4.7 uF per supply domain. Estimated: at 120 MHz active mode with roughly 30 mA typical core+I/O current (per family power figures, 180 uA/MHz x 120 MHz yields about 22 mA core-side before I/O), a linear regulator dissipates (VIN-3.3V) x I; from 5V USB that is about 51 mW, tolerable without heatsinking.
The exposed pad on the underside of the 64-QFN (9x9 mm) must be soldered to a ground pour array of at least a 3x3 pattern of 0.5 mm vias. This pad is the primary ground return and thermal path; an unsoldered or voided pad is the most common cause of erratic reset and ADC-noise complaints on QFN MCUs. Follow Microchip's QFN land-pattern guidelines (typical stencil: 80% pad coverage with window-pane aperture) for reliable reflow.
The SAM-ICE/Atmel-ICE (CMSIS-DAP) debug interface uses SWD plus ERASE/NRST pins; reserve all four pads in production even if JTAG is unused, because field reprogramming and fault diagnosis depend on it. Do not leave NRST unconnected to a test point. Also note the ERASE pin asserts full flash erase when driven high - keep it grounded or resistively tied low on production boards to prevent accidental mass erase during ESD events.
Estimated: with core current near 30 mA at 3.3V (about 0.1 W dissipation) and QFN theta_JA typically in the 30-40 C/W class for a 9x9 mm exposed-pad package on a good 4-layer board, junction rise is only 3-4 C above ambient, so no thermal management is needed for the MCU itself at full 120 MHz operation. Ensure surrounding power components (regulators, drivers), not the MCU, dominate the thermal budget of the layout.
Compliance Information
Mouser listing describes the part as GRNIND (green, industrial) MRL A, indicating RoHS/green packaging compliance per Microchip's material declarations. Full REACH and conflict-minerals status should be confirmed via Microchip's official material declaration search.
