ATSAM4LS4BA-UUR - 48MHz Cortex-M4 MCU 256KB Flash | Microchip
MPN: ATSAM4LS4BA-UUR ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $7.42 | $7.42 |
| 10 | $6.68 | $66.80 |
| 100 | $6.5123 | $651.23 |
| 500 | $6.12 | $3,060.00 |
| 1,000 | $5.75 | $5,750.00 |
ATSAM4LS4BA-UUR Overview
A microcontroller unit (MCU) is a single integrated circuit that combines a processor core, memory, and programmable peripherals into one chip, forming the lowest layer of the embedded systems hierarchy: MCU -> embedded processor -> system-on-chip -> semiconductor device. The SAM4L family belongs to Atmel (now Microchip Technology) ARM-based flash microcontrollers, positioned for low-power embedded control.
Key features include the high-performance 32-bit ARM Cortex-M4 RISC processor core, 10-bit and 12-bit ADC options for analog sensing, and operation across multiple nominal supply rails of 1.8V, 2V, 2.3V, and 3.3V. The extremely compact 64-WLCSP (4.31 x 4.43 mm) ball grid array package makes the device attractive for space-constrained portable electronics where board area is the dominant constraint.
Technically, the SAM4L series is a member of a family of flash microcontrollers based on the high-performance 32-bit ARM Cortex-M4 RISC processor. The Cortex-M4 core brings hardware DSP instructions and single-cycle MAC capability, allowing filtering and control-loop math to execute efficiently at the modest 48 MHz clock while preserving the SAM4L series low-power design philosophy.
Typical applications include battery-powered portable instruments, wearable and sensor-node designs, industrial sensing front-ends using the 10/12-bit ADCs, and compact embedded controllers where a 32-bit ARM ecosystem with 256KB of on-chip flash is required in a minimal footprint.
A key design consideration is the WLCSP package itself: wafer-level chip-scale balls demand tight PCB pad accuracy and reflow control, and the underside ball array requires careful via-in-pad or escape-routing strategy for signal access.
This page synthesizes distributor pricing, drop-in family alternatives, comparison data, and practical WLCSP layout guidance not consolidated in the manufacturer datasheet.
Drop-in alternatives for ATSAM4LS4BA-UUR — 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 ATSAM4LS4BA-UUR (same form factor and footprint) — differing in Core Size, Package, Packaging, ADC Resolution, Flash Memory.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
ATSAM4LC4BA-UUR
✅ Drop-In✓ In Stock
Contact for price
View Datasheet →ATSAM4LC8BA-UUR
✅ Drop-In ⚠️ 参数待验证✓ In Stock
$3.95 / Unit
View Datasheet →ATSAM4LS8BA-UUR
✅ Drop-In ⚠️ 参数待验证✓ In Stock
$2.03 / Unit
View Datasheet →ATSAM4LS2BA-UUR
✅ Drop-In ⚠️ 参数待验证📋 Reference alternative (not in catalog)
ATSAM4LC2BA-UUR
✅ Drop-In ⚠️ 参数待验证📋 Reference alternative (not in catalog)
ATSAM4LS4BA-UUR Maximum Ratings & Electrical Characteristics
| Core Processor | ARM Cortex-M4 |
| Core Size | 32-Bit |
| Maximum Clock Frequency | 48 MHz |
| Program Memory Type | FLASH |
| Program Memory Size | 256KB (256K x 8) |
| RAM Size | 32K x 8 |
| Supply Voltage Range (Vcc/Vdd) | 1.62V to 3.6V |
| Nominal Supply Voltages | 1.8V / 2V / 2.3V / 3.3V |
| Series | SAM4L |
| ADC Resolution | 10-bit and 12-bit |
| Package | 64-WLCSP (4.31 x 4.43 mm) |
| Supplier Device Package | 64-WLCSP (4.31x4.43) |
| Terminal Form | Ball Grid Array (WLCSP) |
| Number of Terminals | 64 |
| Mounting Type | Surface Mount |
| Packaging | Tape & Reel (T/R) |
ATSAM4LS4BA-UUR 64-wlcsp (4.31x4.43) Pin Configuration Guide
Pin configuration for ATSAM4LS4BA-UUR (64-wlcsp (4.31x4.43) 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 ATSAM4LS4BA-UUR.
Refer to the datasheet for full pin configuration.
Typical Applications
ATSAM4LS4BA-UUR is suitable for 6 applications: Wearable and Portable Devices, Battery-Powered Sensor Nodes, Industrial Analog Sensing Front-Ends, Compact Embedded Controllers, Health and Medical Monitoring Devices, IoT Edge Nodes and Smart Home Devices.
Wearable and Portable Devices
The ATSAM4LS4BA-UUR fits wearables because its 64-ball WLCSP measures only 4.31 x 4.43 mm, one of the smallest footprints available for a 256KB flash 32-bit ARM MCU, freeing board area for battery and sensors. The 1.62V to 3.6V supply range allows direct connection to a 3V coin cell or single-cell primary lithium across its full discharge curve, eliminating a regulator stage. The 48 MHz Cortex-M4 with hardware DSP instructions processes sensor fusion and filtering locally at low clock rates, conserving energy compared with higher-clocked parts. Place the MCU on a rigid-flex segment with via-in-pad escapes; the SAM4L low-power architecture supports long standby between sensor samples.
Recommended
Battery-Powered Sensor Nodes
In battery-powered sensor nodes, the ATSAM4LS4BA-UUR aligns through its 10-bit and 12-bit ADCs, which digitize analog sensors without an external converter, and its 1.62V to 3.6V input tolerance that accepts three alkaline cells (4.5V via LDO) or a 3V lithium cell directly. The 48 MHz Cortex-M4 core executes duty-cycled acquisition bursts quickly, so the MCU spends most of its lifetime in sleep. With 256KB flash, protocol stacks such as BLE host layers or LoRaWAN MAC firmware fit on-chip without external storage. Budget sensor excitation and radio transmit as the dominant energy consumers; the MCU contribution shrinks further when sampling intervals exceed one second.
Recommended
Industrial Analog Sensing Front-Ends
Industrial sensor front-ends benefit from the ATSAM4LS4BA-UUR because the integrated 10-bit and 12-bit ADCs convert 0-3.3V analog channels directly, while the Cortex-M4 single-cycle MAC and DSP instructions run digital filtering (IIR notch, FIR averaging) at 48 MHz without external DSP hardware. The 1.62V to 3.6V tolerance survives the sag and ripple typical of industrial 3.3V rails, and the 256KB flash holds lookup tables, calibration data, and communication firmware simultaneously. Mount the WLCSP on the underside of a four-layer board with a solid ground plane under the ball array; keep ADC reference traces short and star-grounded to preserve effective converter resolution in electrically noisy panels.
Recommended
Compact Embedded Controllers
For compact embedded controllers where a 32-bit ARM ecosystem is required in minimal area, the ATSAM4LS4BA-UUR provides 256KB flash and 32KB SRAM on-chip, sufficient for a bootloader plus application image with room for field firmware updates. The 48 MHz Cortex-M4 delivers roughly 1.25 DMIPS/MHz class throughput adequate for I/O scheduling and lightweight control loops, and the WLCSP-64 ball count exposes enough GPIO for keypad, display, and actuator interfaces in a 4.31 x 4.43 mm body. Design the carrier PCB with HDI microvias and X-ray inspection in the test plan; the concealed ball array prevents optical inspection of solder joints after reflow.
Recommended
Health and Medical Monitoring Devices
Medical monitoring accessories such as pulse oximeters and portable ECG front-ends use the ATSAM4LS4BA-UUR for its combination of 12-bit ADC resolution for physiological signals, DSP capability for digital filtering of motion artifacts, and the small 64-WLCSP body that suits adhesive patch and handheld form factors. The wide 1.62V to 3.6V operating range tolerates battery voltage droop across the full discharge profile, an important reliability factor in safety-relevant wearables. Sample physiologic channels at typical rates of 125 to 500 sps, apply the Cortex-M4 MAC unit to 50/60 Hz notch filtering in firmware, and confirm the final assembly meets applicable medical electrical safety standards for patient-coupled circuits.
Recommended
IoT Edge Nodes and Smart Home Devices
IoT edge nodes leverage the ATSAM4LS4BA-UUR because 256KB of flash accommodates network stacks (MQTT, BLE peripheral profiles) plus application logic, while the 48 MHz Cortex-M4 with DSP instructions handles payload encryption and sensor preprocessing locally. The WLCSP 4.31 x 4.43 mm package lets designers embed compute inside wall plates, door sensors, and bulb form factors where every square millimeter counts, and the 1.62V floor permits direct operation from two NiMH cells (2.4V nominal). Keep the radio power amplifier supply separate from the MCU rail, as transmit bursts of 100-300 mA can induce droop; the MCU tolerance range of up to 3.6V provides headroom for a shared 3.3V rail design.
Recommended
Recommended Products Summary
Engineering reference data for ATSAM4LS4BA-UUR — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | ATSAM4LC4BA-UUR | ATSAM4LC8BA-UUR | ATSAM4LS8BA-UUR | ATSAM4LS2BA-UUR | ATSAM4LC2BA-UUR |
|---|---|---|---|---|---|---|
| Package | 64-WLCSP (4.31 x 4.43 mm) | 64-WLCSP (4.31 x 4.43 mm) - same | 64-WLCSP (4.31 x 4.43 mm) - same | 64-WLCSP (4.31 x 4.43 mm) - same | 64-WLCSP (4.31 x 4.43 mm) - same | 64-WLCSP (4.31 x 4.43 mm) - same |
| Brand | Microchip Technology (Atmel) | Microchip Technology (Atmel) | Microchip Technology (Atmel) | Microchip Technology (Atmel) | Microchip Technology (Atmel) | Microchip Technology (Atmel) |
| Core | ARM Cortex-M4, 32-bit | ARM Cortex-M4, 32-bit | ARM Cortex-M4, 32-bit | ARM Cortex-M4, 32-bit | ARM Cortex-M4, 32-bit | ARM Cortex-M4, 32-bit |
| Maximum Clock Frequency | 48 MHz | 48 MHz | 48 MHz | 48 MHz | 48 MHz | 48 MHz |
| Flash Memory | 256KB (256K x 8) | 256KB | 512KB | 512KB | 128KB | 128KB |
| Supply Voltage Range | 1.62V to 3.6V | 1.62V to 3.6V | 1.62V to 3.6V | 1.62V to 3.6V | 1.62V to 3.6V | 1.62V to 3.6V |
| Family / Peripheral Emphasis | SAM4LS (low-power walk/sleep modes) | SAM4LC (complete feature set) | SAM4LC (complete feature set) | SAM4LS (low-power walk/sleep modes) | SAM4LS (low-power walk/sleep modes) | SAM4LC (complete feature set) |
| Packaging | Tape & Reel (T/R) | Tape & Reel (T/R) | Tape & Reel (T/R) | Tape & Reel (T/R) | Tape & Reel (T/R) | Tape & Reel (T/R) |
Key Differentiators
- Smallest-footprint 256KB ARM MCU option (vs ATSAM4LS4BA-AUR)
- Pin-compatible 512KB flash upgrade (vs ATSAM4LC8BA-UUR)
- Cost-down path without redesign (vs ATSAM4LS2BA-UUR)
Design Notes
The 64-WLCSP (4.31 x 4.43 mm) package uses a fine-pitch ball array on the underside of the die, so route escapes with via-in-pad (filled and plated) or 0.2 mm-class microvias on the layer directly beneath. Use NSMD pads sized per the manufacturer package drawing and follow Microchip WLCSP application guidance for solder-mask opening and reflow profile to avoid solder beading. Because solder joints are invisible after reflow, include X-ray or boundary-scan coverage in your production test plan; optical AOI will only see the perimeter balls.
The 1.62V to 3.6V supply range accepts 1.8V, 2V, 2.3V, and 3.3V nominal rails directly. Decouple each supply ball with 100 nF ceramics placed on the immediate layer beneath the array, plus one bulk 4.7-10 uF capacitor per rail. If sharing a 3.3V rail with radios or motor drivers, isolate the MCU rail with a ferrite bead, since transmit bursts on a shared rail can dip below the 1.62V brown-out threshold. Verify the brown-out reset threshold setting in firmware matches your worst-case rail droop.
Do not confuse the U-suffix WLCSP part with the A-suffix TQFP part (e.g., ATSAM4LS4BA-AUR): although the silicon and memory are identical, the packages are mechanically incompatible and the AUR variant cannot be substituted onto a WLCSP land pattern. Also confirm the SAM4LS versus SAM4LC family selection before tape-out, because peripheral sets differ between the two families even on the same footprint. Flash-size variants within the same package are pin-compatible, but always verify the exact ball map in the current datasheet revision before layout release.
Compliance Information
Compliance status was not stated in the provided verified web data; confirm RoHS/REACH status on the official Microchip product page before ordering.
