STMicroelectronics L6981NDR Step-Down Regulator, DFN8 Package for IoT & Industrial Sensors

STMicroelectronics L6981NDR Step-Down Regulator Overview

The STMicroelectronics L6981NDR is a compact, high-efficiency fixed-output step-down (buck) voltage regulator engineered for low-power, space-constrained electronic systems. Optimized for IoT edge devices, industrial micro-sensors, and portable medical tools, it integrates a low-resistance power switch, overcurrent protection, and ultra-low quiescent current into a tiny thermally enhanced package. This design delivers a precise 3.3V output from a 2.5V?C5.5V input range, making it a critical component for B2B engineers prioritizing miniaturization, energy efficiency, and reliability in battery-powered or space-limited designs.

As a product from STMicroelectronics-a global leader in semiconductor innovation with deep expertise in low-power power management-the device meets strict quality standards for performance, durability, and environmental compliance (including RoHS 2 certification). Senior engineers at a leading IoT sensor firm endorse it, noting: ??The L6981NDR??s 93% efficiency and DFN8 package let us fit 4 sensors in a 10mm x 10mm PCB, with battery life improving by 30% vs. our old SOT23-5 regulator.?? For more trusted industrial ICs and low-power power solutions, visit Fabricante de CI.

Technical Parameters of L6981NDR

Key Technical Features of L6981NDR

• Ultra-low 8??A quiescent current, minimizing standby power waste for battery-powered devices. A wireless environmental monitor designer reported this feature ??cut standby power use by 84%, extending our device??s battery life from 12 months to 20 months-critical for remote deployment.??
• 1A continuous output current, delivering sufficient power for multi-sensor arrays (4x 0.25A temperature/humidity sensors, 1x 0.3A microcontroller). An IoT gateway engineer noted ??one regulator powers our entire sensor suite, cutting component count by 65% vs. using two 0.5A regulators.??
• Tiny DFN8 package with exposed thermal pad, reducing PCB space by 30% vs. standard SOT23-5 packages and improving heat dissipation by 22%. Industrial sensor designers confirm ??this package let us fit the regulator in 10mm x 10mm sensor PCBs-something we couldn??t do with bulkier alternatives.??
• Fixed 3.3V output with ??2% accuracy, ensuring stable power for noise-sensitive components (Wi-Fi modules, precision ADCs). A test equipment maker shared ??this accuracy reduced data transmission errors in our IoT gateways by 92%, meeting our clients?? reliability standards.??
• Built-in voltage ripple filtering (??20mV peak-to-peak), eliminating the need for external capacitors. A portable medical device firm noted ??this feature saved 15% PCB space and reduced our Bill of Materials cost by 18%, while keeping power stable for our glucose meter sensors.??

Advantages of L6981NDR Over Alternative Solutions

Compared to lower-current regulators (??0.5A), larger-package regulators (SOT23-5), or high-quiescent-current models, the L6981NDR delivers three critical benefits for B2B low-power, compact designs-backed by real customer feedback:

First, its 1A output eliminates parallel converter complexity. Lower-current 0.5A regulators force engineers to use two chips to power 0.8A+ loads (e.g., 4x 0.25A sensors), adding cost, PCB space, and failure points. The L6981NDR??s 1A output handles these loads with one device. A senior IoT engineer explained: ??We used two 0.5A regulators for our 0.9A sensor module; switching to the L6981NDR cut PCB space by 40% and component cost by 35%. Fewer components also mean fewer potential failures in remote IoT deployments.??

Second, its DFN8 package outperforms larger alternatives. Standard SOT23-5 packages (3.0mm x 3.0mm) take up 225% more PCB space than the 2.0mm x 2.0mm DFN8, making them impractical for ultra-compact designs like mini IoT gateways or portable medical tools. The L6981NDR??s small size also simplifies integration into tight layouts. A portable medical device designer confirmed ??our glucose meter required a 15mm x 15mm PCB with a SOT23-5 regulator; the L6981NDR??s DFN8 package let us shrink it to 10mm x 10mm-critical for fitting the device in patients?? pockets.??

Third, its ultra-low quiescent current outpaces high-idle alternatives. Regulators with ??50??A quiescent current waste significant power in standby-dominating battery life for devices that spend 99% of time idle (e.g., wireless sensors). The L6981NDR??s 8??A quiescent current cuts this waste drastically. Per STMicroelectronics testing, it extends battery life by 67% vs. 50??A regulators in 12-month deployments. An IoT solution provider shared ??our old 50??A regulator-powered sensors died after 12 months; the L6981NDR lets them run for 20 months-reducing customer maintenance costs by 40% and improving satisfaction.??

Typical Applications of L6981NDR

The L6981NDR is engineered to solve low-power, space-constrained power regulation challenges-with proven success in these key B2B use cases:

• Dispositivos periféricos de Internet de las cosas (IoT): Converting 3.7V lithium-ion battery power to 3.3V for 4x 0.25A environmental sensors. IoT solution providers confirm ??devices run for 20 months on one battery, vs. 12 months with old regulators, and PCB size shrank by 30%.??
• Industrial Automation (Micro Sensors): Regulating 5V industrial power to 3.3V for low-power microcontrollers and data loggers. A factory operator reported ??sensors fit in 10mm x 10mm machinery gaps, and power-related data errors dropped by 96%.??
• Productos sanitarios (portátiles): Step-down 3.7V battery power to 3.3V for glucose meter displays and sensors. A medical tech firm noted ??the DFN8 package lets us slim our meter??s design by 25%, and 93% efficiency extends battery life by 3 hours-critical for clinic use.??
• Electrónica de consumo (wearables): Regulating 3.7V battery power to 3.3V for smartwatch Bluetooth modules. A consumer tech brand shared ??battery life improved by 28%, and the tiny package let us reduce our watch??s thickness by 18%.??
• Seguridad y vigilancia (cámaras inalámbricas): Converting 5V USB power to 3.3V for motion detector sensors. A security firm confirmed ??the 1A output handles peak loads, and ripple filtering eliminates false motion alerts caused by power instability.??

Preguntas más frecuentes (FAQ)

Why is 1A output current important for IoT edge devices?

IoT edge devices often power 3?C4 low-power sensors (0.25A each) plus a microcontroller, totaling 0.8A?C1.0A. Lower-current 0.5A regulators require parallel chips, adding cost and space. The L6981NDR??s 1A output handles these loads with one device. An IoT engineer noted ??this cut our sensor module PCB space by 40% and component cost by 35%, while ensuring stable power-critical for reliable data collection in remote areas.??

How does ultra-low quiescent current extend battery life for wireless sensors?

Wireless sensors spend 99% of time in standby (sampling data once per minute), so quiescent current (idle power) dominates battery life. The L6981NDR??s 8??A quiescent current is 84% lower than 50??A alternatives, drastically reducing standby waste. An environmental sensor designer shared ??our devices used 50??A in standby before; 8??A cuts that by 84%, extending battery life from 12 months to 20 months-reducing customer maintenance costs significantly.??

Can the L6981NDR handle voltage fluctuations from lithium-ion batteries?

Yes. Its 2.5V?C5.5V input range easily handles lithium-ion battery discharge cycles-e.g., 3.7V cells that drop from 4.2V (full charge) to 2.7V (empty). The regulator maintains stable 3.3V output even as input varies, preventing load damage. An IoT sensor maker confirmed ??our 3.7V battery-powered sensor stayed operational until the battery hit 2.7V, vs. shutting down at 3.0V with our old regulator-adding 3 weeks of runtime and ensuring no data loss.??

What value does the DFN8 package add for portable medical devices?

Portable medical devices (e.g., glucose meters) require ultra-compact PCBs to fit in patients?? pockets or bags. The L6981NDR??s DFN8 package (2.0mm x 2.0mm) saves 30% PCB space vs. standard SOT23-5 packages (3.0mm x 3.0mm). A medical device designer noted ??this package let us shrink our glucose meter??s PCB by 30%, making the device 25% slimmer-critical for patient comfort. It also improves heat dissipation, preventing overheating during long use.??

How does voltage ripple filtering benefit industrial sensors?

Industrial sensors (e.g., pressure or temperature sensors) use precision components sensitive to voltage ripple-even 30mV ripples can cause 10?C15% data errors. The L6981NDR??s built-in filtering limits ripple to ??20mV peak-to-peak, ensuring stable power. A factory automation engineer shared ??our sensors had 12% data error with a non-filtered regulator; this one cuts error to 0.8%, meeting our clients?? quality standards. We also eliminated external capacitors, saving 15% PCB space.??