ATSAM3S8BA-MU - 64MHz Cortex-M3, 512KB Flash MCU | Microchip
MPN: ATSAM3S8BA-MU ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $8.26 | $8.26 |
| 10 | $7.85 | $78.50 |
| 100 | $7.07 | $707.00 |
| 500 | $6.36 | $3,180.00 |
| 1,000 | $5.72 | $5,720.00 |
ATSAM3S8BA-MU Overview
A microcontroller unit (MCU) is a single-chip computer that combines a processor core, program memory, data memory, and peripherals such as timers, serial interfaces, and analog-to-digital converters. Within the semiconductor hierarchy, the ATSAM3S8BA-MU belongs to the SAM3S series of 32-bit microcontrollers, which sits above 8-bit MCUs in processing capability and below application processors in complexity, serving the embedded control and power management segment of the industry.
Key features include the ARM Cortex-M3 core with a 3-stage pipeline and Harvard architecture delivering 1.25 DMIPS/MHz, 512 KB of single-cycle flash with a page-erase/word-write controller, a full-speed USB device port with on-chip transceiver, and an asynchronous/synchronous serial controller set including USART, SPI, and TWI (I2C). A 12-bit ADC and 10-bit DAC support mixed-signal designs, and an internal RC oscillator plus PLL system allow clock generation from multiple sources.
Technical depth: the SAM3S series employs a multi-layer AHB bus matrix that lets the CPU, DMA channels, and USB access different slaves concurrently, reducing bus contention. Embedded flash controllers with wait-state acceleration keep zero-wait-state execution across the 64 MHz operating range. The exposed-pad QFN package provides a low-inductance ground path, aiding analog performance and thermal dissipation.
Typical applications include consumer and industrial human-machine interfaces with LCD and touch-sensing support, battery-powered portable instruments, and USB-connected industrial sensors where the integrated USB device port removes the need for a separate USB interface chip.
Design consideration: use a solid ground connection to the exposed pad and decouple each VDDIO/VDDCORE pin pair with 100 nF capacitors placed within 2 mm of the pins; flash programming requires VDDCORE within its specified range during erase/write operations.
This page synthesizes distributor pricing, drop-in family alternatives, and practical design notes not found in the manufacturer datasheet, with pricing verified as of 2026-09-19.
Drop-in alternatives for ATSAM3S8BA-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 ATSAM3S8BA-MU (same form factor and footprint) — differing in Package, Supply Voltage, Flash Memory, RoHS Status, SRAM.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
ATSAM3S8BA-MUR
✅ Drop-In✓ In Stock
$5.15 / Unit
View Datasheet →ATSAM3S4BA-MU
✅ Drop-In ⚠️ 参数待验证✓ In Stock
$5.12 / Unit
View Datasheet →ATSAM3S2BA-MU
✅ Drop-In ⚠️ 参数待验证📋 Reference alternative (not in catalog)
ATSAM3SD8BA-MU
✅ Drop-In ⚠️ 参数待验证✓ In Stock
$4.95 / Unit
View Datasheet →ATSAM3N4BA-MU
✅ Drop-In ⚠️ 参数待验证✓ In Stock
$3.48 / Unit
View Datasheet →ATSAM3S8BA-MU Maximum Ratings & Electrical Characteristics
| Core | ARM Cortex-M3, 32-bit |
| Core Clock Speed | 64 MHz |
| Flash Memory | 512 KB (512K x 8) |
| Supply Voltage | 1.8 V / 2.5 V / 3.3 V |
| Core Supply Voltage Range | 1.08 V to 1.32 V |
| I/O Count | 47 |
| Package | 64-QFN (9x9 mm) Exposed Pad |
| Mounting Type | Surface Mount |
| USB | USB 2.0 Full-Speed Device |
| ADC Resolution | 12-bit and 10-bit |
| Series | SAM3S8 |
| Interface Peripherals | USART, SPI, TWI (I2C) |
| Life Cycle Stage | Active |
| Pin Count | 64 |
| Core Architecture | RISC, Harvard, 3-stage pipeline |
| Pin Compatibility | Pin-to-pin compatible with SAM7S series |
ATSAM3S8BA-MU 64-qfn (9x9 mm) exposed pad Pin Configuration Guide
Pin configuration for ATSAM3S8BA-MU (64-qfn (9x9 mm) 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 ATSAM3S8BA-MU.
Refer to the datasheet for full pin configuration.
Typical Applications
ATSAM3S8BA-MU is suitable for 6 applications: Industrial HMI and Touch Control Panels, USB-Connected Portable Instruments, Data Logging and Telemetry Nodes, Motor Control and Power Conversion Supervision, Consumer Appliance Controllers, SAM7S Legacy Migration Upgrades.
Industrial HMI and Touch Control Panels
The ATSAM3S8BA-MU fits industrial human-machine interface designs because its 512 KB flash accommodates graphics libraries, fonts, and multi-language strings, while the 64 MHz Cortex-M3 core provides the processing headroom for display refresh and touch decoding. Its 47 GPIO lines and SPI/parallel-style bus interfaces drive LCD modules and keypads directly. Placed as the single system MCU, it removes an external display controller: USB or USART links the panel to the host PLC, and the 12-bit ADC reads potentiometers and ambient sensors. The trade-off is the need to manage flash wait states at full 64 MHz operation, mitigated by the embedded flash accelerator.
Recommended
USB-Connected Portable Instruments
Battery-powered instruments benefit from the ATSAM3S8BA-MU's integrated USB 2.0 full-speed device controller, which eliminates a dedicated USB interface chip and its cost. The device enumerates as a CDC or HID class device to a PC, streaming measurement data over the on-chip transceiver while the 12-bit ADC digitizes sensor channels. The series' low-power modes extend battery life during idle periods, and 1.8V operation supports single-cell derived rails. A design consideration: USB VBUS detection circuitry must be included on the board, and the 512 KB flash leaves room for field firmware updates delivered over the same USB link, simplifying maintenance of deployed instruments.
Recommended
Data Logging and Telemetry Nodes
The ATSAM3S8BA-MU serves data-logging nodes where 512 KB of internal flash stores calibration tables, ring buffers, and even modest local logs, and external SD or SPI flash extends capacity over the dedicated SPI controller. Multiple USART channels accept RS-485 or radio-module links simultaneously, and the 12-bit ADC samples analog sensor inputs at resolutions suited to temperature and pressure measurement. The Harvard-architecture core sustains DMA-driven buffer movement without CPU stalls thanks to the multi-layer bus matrix. Engineers should budget the flash for wear-leveled logging only at low write rates, since internal flash endurance is shared with code storage.
Recommended
Motor Control and Power Conversion Supervision
In power-conversion and motor-drive supervision roles, the ATSAM3S8BA-MU acts as the system supervisor communicating with a dedicated power stage controller over SPI or USART. Its 12-bit ADC monitors bus voltage, current shunt outputs, and temperature at 1.08-1.32 V core stability, while fast GPIO toggles enable and fault lines with microsecond latency. The 64 MHz core executes protection algorithms and protocol stacks concurrently. This arrangement keeps the safety-critical switching loops on specialized silicon while the SAM3S8 handles sequencing, telemetry, and user interfaces - a partitioning that simplifies functional-safety documentation for the main control path.
Recommended
Consumer Appliance Controllers
Home appliance control boards use the ATSAM3S8BA-MU to unify touch or rotary user interfaces, motor start/stop sequencing, and USB service ports in one device. The 512 KB flash holds interface assets and communication firmware with margin for OTA-style service updates, and the 10-bit/12-bit converters read NTC thermistors and user-adjustable analog dials directly. Running from a 3.3 V rail derived from the appliance supply, the MCU's exposed-pad QFN conducts heat and noise to the ground plane, improving ADC repeatability in electrically noisy environments. Designers should add RC filtering on analog inputs located near relays and triac drivers on the same board.
Recommended
SAM7S Legacy Migration Upgrades
The SAM3S8/SD8 series is pin-to-pin compatible with the Atmel SAM7S series, so legacy boards designed around ATSAM7S512 or ATSAM7S256 can be upgraded to the Cortex-M3-based ATSAM3S8BA-MU without PCB respin. This gives aging products a 64 MHz 32-bit core, modern toolchain support, and continued silicon availability while reusing validated hardware. The engineering effort concentrates on software: the ARM7TDMI codebase must be ported to Cortex-M3 interrupt handling (NVIC) and CMSIS conventions. Teams should budget for peripheral-driver revalidation even though register maps remain largely similar across the Atmel 32-bit families.
Recommended
Recommended Products Summary
Engineering reference data for ATSAM3S8BA-MU — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | ATSAM3S8BA-MUR | ATSAM3S4BA-MU | ATSAM3S2BA-MU | ATSAM3N4BA-MU |
|---|---|---|---|---|---|
| Package | 64-QFN (9x9 mm) Exposed Pad | 64-QFN (9x9 mm) EP - same | 64-QFN (9x9 mm) EP - same | 64-QFN (9x9 mm) EP - same | 64-QFN (9x9 mm) EP - same |
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Core / Clock | Cortex-M3, 64 MHz | Cortex-M3, 64 MHz | Cortex-M3, 64 MHz | Cortex-M3, 64 MHz | Cortex-M3, 96 MHz max (series) |
| Flash Memory | 512 KB | 512 KB | 256 KB | 128 KB | 256 KB |
| USB Device | Yes (FS device) | Yes (FS device) | Yes (FS device) | Yes (FS device) | No |
| ADC | 12-bit and 10-bit | 12-bit and 10-bit | 12-bit and 10-bit | 12-bit and 10-bit | 12-bit and 10-bit |
| I/O Ports | 47 | 47 | 47 | 47 | 47 |
Key Differentiators
- Maximum flash capacity in the 64-QFN SAM3S family (vs ATSAM3S4BA-MU)
- Integrated USB 2.0 full-speed device (vs ATSAM3N4BA-MU)
- Sam7S legacy hardware compatibility (vs ATSAM3S2BA-MU)
Design Notes
The 64-QFN exposed pad must be soldered to a continuous ground pour with an array of thermal vias (typically 3x3 to 5x5 via grid) to provide both the primary ground return and heat dissipation path. VDDIO and VDDCORE pin pairs each require a 100 nF ceramic decoupling capacitor within 2 mm of the pin, plus at least one bulk 4.7 uF per supply domain. Route the USB D+/D- pair as a 90-ohm differential pair with length matching better than 1 mm for reliable full-speed enumeration.
The core supply (VDDCORE) must stay within 1.08 V to 1.32 V at all times, and the internal regulator options depend on the selected system voltage (1.8/2.5/3.3 V). Estimated: at 64 MHz with all peripherals active, expect roughly 30-40 mA total supply current (typical-class figure; verify in the datasheet power consumption tables for your peripheral mix). Ensure the 3.3 V rail can supply inrush for internal regulator startup and that brown-out reset is enabled so flash programming never occurs outside the valid VDDCORE window.
Because the SAM3S8 series is pin-to-pin compatible with SAM7S parts, teams upgrading legacy boards often assume firmware portability - but the Cortex-M3 NVIC, vector table format, and some peripheral register behaviors differ from the ARM7TDMI SAM7S. Re-test interrupt priority schemes and re-derive clock tree settings (PLL multipliers/dividers) for the 64 MHz target. Also verify that I/O voltage levels match attached peripherals when changing the VDDIO rail from 5 V-tolerant assumptions on older designs.
Keep the crystal/oscillator loop (main oscillator and 32 kHz RTC crystal if used) compact with ground guard traces, and place the analog reference decoupling away from switching traces. Group ADC input nets away from USB and high-drive GPIO lines. For the QFN package, avoid routing signals directly beneath the exposed pad area; use inner layers with stitching vias to maintain a low-impedance reference plane under the part.
Compliance Information
Compliance status not stated in provided web data. Modern Microchip SAM3S parts are generally RoHS compliant, but this must be verified on the official Microchip product page before publication.
