ATSAM3S8BA-MUR - 64MHz Cortex-M3 MCU 512KB Flash | Microchip
MPN: ATSAM3S8BA-MUR β Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $6.92 | $6.92 |
| 10 | $6.5 | $65.00 |
| 100 | $6.05 | $605.00 |
| 500 | $5.6 | $2,800.00 |
| 1,000 | $5.15 | $5,150.00 |
ATSAM3S8BA-MUR Overview
A microcontroller (MCU) is a single integrated circuit that combines a processor core, non-volatile program memory, SRAM data memory, and a rich set of peripheral interfaces into one chip, forming the compute layer of an embedded system. Within the component hierarchy, the SAM3S8B belongs to the 32-bit MCU family, under ARM-based microcontrollers, under the broader category of semiconductors and integrated circuits.
Key features include the ARM Cortex-M3 RISC core at 64 MHz, 512 KB of on-chip Flash and 64 KB of SRAM, a USB 2.0 Full-Speed Device port (12 Mbps, 2668-byte FIFO, up to 8 bidirectional endpoints) with on-chip transceiver, and industrial temperature operation. According to the Microchip SAM3S8B product page, the extended peripheral set supports embedded designs that need both connectivity and analog control in a compact footprint.
Technically, the device integrates up to 3 USARTs supporting ISO7816, IrDA, RS-485, SPI, Manchester and modem modes, two 2-wire UARTs, up to 2 TWI (I2C-compatible) interfaces, 1 SPI, 1 Serial Synchronous Controller (I2S), 1 high-speed multimedia card interface (SDIO/SD Card/MMC), and 6 three-channel 16-bit Timer/Counters. The supply range is 1.62 V to 3.6 V, allowing single-supply battery operation with an internal regulator.
Typical applications include industrial control panels, consumer devices with USB connectivity, battery-powered metering, and data-logging systems that leverage the SD/MMC interface.
A key design consideration is supply decoupling: use low-ESR ceramic capacitors on VDDIO and VDDCORE per the datasheet power scheme, and note that GPIO current must be budgeted across I/O banks.
This page adds value beyond the manufacturer datasheet by consolidating distributor pricing (LCSC from $6.9177 as of 2026-09-19), drop-in same-family alternatives, and practical design guidance in one AI-citable resource.
Drop-in alternatives for ATSAM3S8BA-MUR β 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-MUR (same form factor and footprint) β differing in Core Processor, Core Size, Maximum Clock Frequency, RoHS Status.
Quick Comparison Tool β Select alternative parts for side-by-side comparison:
ATSAM3S8BA-MU
β Drop-Inπ Reference alternative (not in catalog)
ATSAM3SD8BA-MUR
β Drop-Inβ In Stock
$3.98 / Unit
View Datasheet βATSAM3S4BA-MUR
β Drop-In β οΈ εζ°εΎ ιͺθ―π Reference alternative (not in catalog)
ATSAM3S2BA-MUR
β Drop-In β οΈ εζ°εΎ ιͺθ―π Reference alternative (not in catalog)
ATSAM3N4BA-MU
β Drop-Inβ In Stock
$3.48 / Unit
View Datasheet βATSAM3S8BA-MUR Maximum Ratings & Electrical Characteristics
| Core Processor | ARM Cortex-M3 |
| Core Size | 32-Bit Single-Core |
| Maximum Clock Frequency | 64 MHz |
| Flash Memory | 512 KB (512K x 8) |
| SRAM | 64 KB |
| Supply Voltage Range | 1.62 V to 3.6 V |
| USB | USB 2.0 Full-Speed Device, 12 Mbps, on-chip transceiver, 2668 byte FIFO, up to 8 bidirectional endpoints |
| USARTs | Up to 3 (ISO7816, IrDA, RS-485, SPI, Manchester, Modem modes) |
| UARTs | 2 |
| TWI (I2C-compatible) | Up to 2 |
| SPI | 1 |
| Serial Synchronous Controller | 1 (I2S) |
| High Speed Multimedia Card Interface | 1 (SDIO/SD Card/MMC) |
| Timers | 6 x Three-Channel 16-bit Timer/Counter |
| Connectivity | I2C, IrDA, Memory Card, SPI, SSC, UART/USART, USB |
| Package | 64-QFN (9x9 mm) |
| Mounting Type | Surface Mount |
| Temperature Grade | Industrial |
| RoHS Status | Compliant (Green package per Mouser listing) |
ATSAM3S8BA-MUR 64-qfn (9x9 mm) Pin Configuration Guide
Pin configuration for ATSAM3S8BA-MUR (64-qfn (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 ATSAM3S8BA-MUR.
Refer to the datasheet for full pin configuration.
Typical Applications
ATSAM3S8BA-MUR is suitable for 6 applications: Industrial Control and Automation, USB Consumer Devices, Battery-Powered Data Logging, Metering and Smart Energy, Audio and Human-Machine Interfaces, Security and Access Control.
Industrial Control and Automation
Industrial control nodes benefit directly from the ATSAM3S8BA-MUR combination of a 64 MHz Cortex-M3 core and the SAM3S peripheral set. The six three-channel 16-bit Timer/Counters provide 18 independent timing resources for PWM motor control, quadrature decoding, and precise event capture, while up to 3 USARTs with RS-485 mode enable robust multi-drop fieldbus communication. The industrial temperature grade suits factory-floor environments, and the 1.62 V to 3.6 V supply range simplifies integration with standard 3.3 V logic. Because 512 KB Flash holds protocol stacks plus application code with headroom for field firmware updates, the part fits PLC auxiliary modules, sensor hubs, and actuator controllers. Place the device between RS-485 transceivers and isolated I/O, using the Timer/Counter PWM outputs for actuator drive.
Recommended
USB Consumer Devices
The ATSAM3S8BA-MUR integrates a USB 2.0 Full-Speed Device controller with an on-chip transceiver, 2668-byte FIFO, and up to 8 bidirectional endpoints, eliminating an external USB PHY. This makes it a natural fit for consumer peripherals such as card readers, audio accessories, and PC-connected gadgets. The 512 KB Flash accommodates a full USB device stack with mass-storage or HID classes plus application firmware, and the 64 KB SRAM supports endpoint buffering alongside application data. The 12 Mbps Full-Speed bandwidth suits device-class traffic rather than bulk streaming. In a typical design, the MCU's DDM/DDP lines connect directly to the USB connector through the integrated transceiver, with VBUS sensing handled by a GPIO; no external crystal beyond the main oscillator is required for USB clocking, thanks to the internal USB-capable PLL.
Recommended
Battery-Powered Data Logging
Battery-powered loggers pair the ATSAM3S8BA-MUR with its High Speed Multimedia Card Interface supporting SDIO, SD Card, and MMC formats, letting large datasets be written to removable media without host intervention. The 1.62 V to 3.6 V single-supply range allows direct operation from two alkaline cells or a Li-ion pack, and Cortex-M3 sleep and wait modes reduce average current between logging events. The 64 KB SRAM buffers sensor samples during write latency, while the 512 KB Flash retains code plus configuration tables. The device's SPI and TWI ports connect external ADCs and sensors, and USARTs stream data from GPS or radio modules. Design consideration: budget SD-card write current (up to ~100 mA peaks) separately from the MCU supply, and use sleep modes between samples to extend battery life in multi-year deployments.
Recommended
Metering and Smart Energy
Energy meters and smart-meter peripherals exploit the SAM3S8B's balance of computation and connectivity. The 64 MHz Cortex-M3 core executes metering algorithms and CRC-protected protocol framing, while up to 3 USARTs (with ISO7816 mode for smart-card readers) and 2 TWI interfaces connect tariff displays, energy-measurement front ends, and tamper sensors. The on-chip SD/MMC interface archives load profiles on removable cards. Operating from 1.62 V to 3.6 V, the device runs directly from a 3.3 V meter supply, and industrial temperature grading covers outdoor meter enclosures. The 16-bit Timer/Counters generate PWM for valve or relay control in prepayment meter variants. With 512 KB Flash, the firmware holds metering libraries, DLMS/COSEM-style protocol layers, and an in-application-programming bootloader for remote firmware upgrade.
Recommended
Audio and Human-Machine Interfaces
The Serial Synchronous Controller (I2S-capable) on the ATSAM3S8BA-MUR streams digital audio to external codecs, and the 64 MHz Cortex-M3 handles protocol translation, button decoding, and display refresh. Consumer and industrial HMI panels use the TWI interfaces for touch controllers, SPI for TFT display modules, and USARTs for backend communication, all while USB provides configuration or firmware-update links to a host PC. The 64 KB SRAM supports display line buffering and audio sample queues, and 512 KB Flash stores fonts, GUI assets, and a USB DFU bootloader. The 1.62 V to 3.6 V supply matches typical codec and display logic levels. Performance consideration: keep I2S bit-clock rates within Timer/Counter and SSC timing limits per the datasheet, and use DMA-driven SSC transfers to keep CPU load low during continuous audio playback.
Recommended
Security and Access Control
Access-control readers and security panels use the ATSAM3S8BA-MUR's ISO7816-capable USARTs for smart-card communication, its TWI interfaces for secure element and keypad controllers, and its Timer/Counters for buzzer and LED timing. The 512 KB Flash supports cryptographic libraries and credential databases locally, while the USB Device port enables desktop enrollment and firmware updates through the same connector. Industrial temperature rating and the 1.62 V to 3.6 V supply range fit door-controller hardware powered from 12 V rails via simple regulators. The six three-channel 16-bit Timer/Counters drive relay timing, Wiegand pulse capture with precise bit timing, and watchdog functions. With USB and smart-card on one chip, the BOM shrinks compared with two-chip USB-plus-card solutions, reducing board area in slim reader housings.
Recommended
Recommended Products Summary
Engineering reference data for ATSAM3S8BA-MUR β comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | ATSAM3S8BA-MU | ATSAM3SD8BA-MUR | ATSAM3S4BA-MUR | ATSAM3S2BA-MUR |
|---|---|---|---|---|---|
| Package | 64-QFN (9x9 mm) | 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 |
| Core / Clock | ARM Cortex-M3, 64 MHz | ARM Cortex-M3, 64 MHz | ARM Cortex-M3, 64 MHz | ARM Cortex-M3, 64 MHz | ARM Cortex-M3, 64 MHz |
| Flash Memory | 512 KB | 512 KB | 512 KB | 256 KB | 128 KB |
| SRAM | 64 KB | 64 KB | 64 KB | 48 KB | 32 KB |
| USB 2.0 Device | Yes, 12 Mbps, 8 endpoints | Yes, 12 Mbps | Yes, 12 Mbps | Yes, 12 Mbps | Yes, 12 Mbps |
| Peripheral Emphasis | Standard SAM3S8B set (3 USART, 2 TWI, SPI, SSC, HSMCI) | Identical to this product | SD-variant set (DACC emphasis) | Same set, smaller memory | Same set, smaller memory |
| Packaging / Sourcing | Tape & Reel (MUR) | Tray (MU) | Tape & Reel | Tape & Reel | Tape & Reel |
Key Differentiators
- Full 512 KB Flash in the pin-limited 64-pin package (vs ATSAM3S4BA-MUR)
- Lowest-cost same-pinout option for smaller firmware (vs ATSAM3S2BA-MUR)
- Packaging flexibility for production volume (vs ATSAM3S8BA-MU)
- Standard peripheral set vs SD analog variant (vs ATSAM3SD8BA-MUR)
Design Notes
The ATSAM3S8BA-MUR operates from 1.62 V to 3.6 V with an internal regulator supplying the core from VDDIO/VDDIN. Decouple VDDIO, VDDCORE, VDDPLL, and VDDUSB independently with 100 nF ceramic capacitors placed within 2 mm of each pin, plus bulk 4.7-10 uF per supply domain per the SAM3S datasheet power scheme. When powering from USB VBUS (5 V), use a 3.3 V LDO rated for at least 150 mA to cover MCU plus SD-card write peaks. Never leave VDDCORE decoupling unpopulated - core instability manifests as sporadic watchdog resets that are difficult to diagnose.
The 64-QFN (9x9 mm) package has a central exposed pad that must be soldered to a grounded thermal land pattern with an array of vias for reliable grounding and heat dissipation. Use a 0.5 mm pitch fanout with via-in-pad or dogbone escapes. Keep the USB DDM/DDP traces as a 90-ohm differential pair, length-matched within 1 mm, routed away from the HSMCI clock lines. The SD/MMC interface benefits from series 22-33 ohm resistors on CMD and clock lines to control ringing at card connectors on long traces.
Two common mistakes: (1) Flash memory requires the proper wait-state configuration as clock frequency changes - the flash accelerator and wait states must be programmed before raising the core to 64 MHz, or code execution will corrupt; always follow the startup sequence in the Microchip startup files (EEFC configuration before clock switching). (2) Pin multiplexing on the 64-QFN means many peripherals share pins - verify the datasheet signal-multiplexing tables for your exact peripheral combination early in schematic capture, since not all peripheral functions are available simultaneously on the 64-pin variant.
Estimated: A Cortex-M3 MCU at 64 MHz typically dissipates well under 300 mW (3.3 V x ~50-90 mA full-active, depending on peripherals), producing a junction rise of only a few degrees C over ambient with the QFN exposed pad soldered to a ground pour. Thermal design is rarely the limiting factor; instead, ensure the exposed pad is actually connected to ground - a floating pad raises die temperature slightly and, more importantly, degrades EMC performance by removing the low-inductance ground return.
Compliance Information
Mouser lists the part as 'QFN,Green,IND TEMP,MRL A', indicating a green (halogen-free) package with industrial temperature grade. REACH and conflict-minerals declarations should be obtained from the Microchip product compliance documentation.
