STMicroelectronics ST1S10PHR Step-Down DC DC Converter, DFN8 Package for Low-Power IoT

STMicroelectronics ST1S10PHR Step-Down DC DC Converter Overview

The STMicroelectronics ST1S10PHR is a high-efficiency, synchronous step-down (buck) DC DC converter engineered for low-power, space-constrained electronic systems-optimized for IoT edge devices, portable medical tools, and compact industrial sensors. It integrates a synchronous power stage (dual low-resistance MOSFETs), programmable output voltage, and ultra-low quiescent current into a tiny package, delivering stable, regulated power from a wide input range to low-voltage loads like microcontrollers, multi-sensor arrays, and wireless modules. This makes it a critical component for B2B engineers prioritizing energy efficiency, miniaturization, and reliable power delivery 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-this converter 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 ST1S10PHR??s 96% efficiency and 1A output let us power 4 sensors in a 12mm x 12mm PCB, with battery life improving by 32% vs. our old converter.?? For more trusted industrial ICs and low-power power management solutions, visit IC Manufacturer.

Technical Parameters of ST1S10PHR

Key Technical Features of ST1S10PHR

• Synchronous power stage with low on-resistance (R_DS(on)) MOSFETs, eliminating the need for external Schottky diodes and reducing power losses-critical for maximizing battery life in portable devices. A wearable tech designer reported this feature ??cut power loss by 45% vs. asynchronous converters, extending our fitness tracker battery life by 4 days.??
• Ultra-low quiescent current (15??A typical at light load; 0.1??A in shutdown), minimizing power waste when devices are in standby (e.g., IoT sensors that sample data once per minute). An environmental sensor firm confirmed ??standby power use dropped by 85%, letting our devices run for 20 months on one AA battery.??
• Tiny DFN8 package (2.0mm x 2.0mm), reducing PCB space by 30% vs. standard SOT23-6 packages. IoT gateway engineers note: ??This package let us fit the converter alongside 10 other components in a 15mm x 15mm PCB-something we couldn??t do with bulkier alternatives.??
• Programmable output voltage (0.8V?C3.6V) via a single external resistor, enabling compatibility with a wide range of low-voltage loads (e.g., 0.9V microcontrollers, 1.8V sensors, 3.3V wireless modules). A medical device designer shared ??one converter powers 3 different loads in our portable pulse oximeter, cutting component count by 55%.??
• Built-in voltage ripple filtering (??20mV peak-to-peak), ensuring stable power for noise-sensitive components like precision sensors. An industrial sensor maker noted ??this feature reduced data errors from power instability by 95%, improving sensor accuracy for our factory clients.??

Advantages of ST1S10PHR Over Alternative Solutions

Compared to asynchronous step-down converters, larger-package converters, or low-current alternatives, the ST1S10PHR delivers three critical benefits for B2B low-power designs-backed by real customer feedback:

First, its synchronous design outperforms asynchronous converters in efficiency. Asynchronous converters use external Schottky diodes that cause significant power losses (especially at high currents), limiting efficiency to 75?C80%. The ST1S10PHR??s integrated synchronous MOSFETs eliminate this loss, boosting efficiency to 96% at typical loads. A wearable tech engineer explained: ??We switched from an asynchronous converter to the ST1S10PHR, and our fitness tracker??s battery life jumped from 5 days to 8 days-users no longer need weekly charges.?? This efficiency also reduces heat generation, critical for compact devices with no cooling.

Second, its 1A output current outpaces low-current converters (??600mA). Low-current models force engineers to use parallel converters to power multi-sensor arrays (e.g., 4x 0.2A sensors = 0.8A total), adding cost and PCB space. The ST1S10PHR??s 1A output powers 4+ sensors with one chip. An IoT sensor designer confirmed ??we used to need two 600mA converters for our 4-sensor module; now we use one ST1S10PHR, cutting PCB space by 40% and component cost by 30%.?? This simplifies design and reduces failure points.

Third, its DFN8 package and ripple filtering outpace bulkier, unfiltered alternatives. Standard SOT23-6 converters (3.0mm x 3.0mm) take up 225% more PCB space than the DFN8, making them impractical for ultra-compact designs. Additionally, many converters lack built-in ripple filtering, requiring external capacitors that waste space. The ST1S10PHR??s integrated filtering eliminates extra components, while its DFN8 package fits tight layouts. A medical device firm shared ??our portable glucose meter needed 3 extra capacitors with a SOT23-6 converter; the ST1S10PHR??s built-in filtering let us remove them, shrinking the meter by 20% and improving reliability.??

Typical Applications of ST1S10PHR

The ST1S10PHR is engineered to solve low-power, space-constrained power regulation challenges-with proven success in these key B2B use cases:

• Internet of Things (IoT) Edge Devices: Powering 3.3V Wi-Fi modules and 4x 1.8V sensors from 3.7V lithium-ion batteries. IoT solution providers confirm ??devices run for 20 months on one battery, vs. 12 months with old converters, and PCB size shrank by 30%.??
• Medical Devices (Portable): Regulating 3.7V battery power to 1.8V for glucose meter sensors and 3.3V for displays. A medical tech firm noted ??the converter??s small size let us make our meter 25% smaller, and 96% efficiency extends battery life during 10-hour clinic shifts.??
• Industrial Automation (Mini Sensors): Converting 5V industrial power to 0.9V for low-power microcontrollers and 3.3V for data loggers. A factory operator reported ??sensors fit in 12mm x 12mm machinery gaps, and power-related data errors dropped by 98%.??
• Consumer Electronics (Wearables): Step-down 3.7V battery power to 1.2V for fitness tracker accelerometers and 3.3V for Bluetooth modules. A consumer tech brand shared ??battery life improved by 32%, and the tiny package let us slim our tracker??s design by 20%.??
• Home Appliances (Smart Sensors): Regulating 5V USB power to 3.3V for smart thermostat sensors and 1.8V for motion detectors. A home tech maker confirmed ??sensors use 45% less power, and the small size let us hide them in thermostat housings.??

Frequently Asked Questions (FAQ)

Why is synchronous design important for battery-powered IoT devices?

Synchronous converters use two integrated MOSFETs (instead of one MOSFET + external diode) to eliminate diode power losses, which are a major efficiency drain in battery devices. The ST1S10PHR??s synchronous design boosts efficiency to 96%, vs. 75?C80% for asynchronous converters. An IoT engineer noted: ??This efficiency gap let our 3.7V battery-powered sensor run for 20 months instead of 12-cutting customer battery replacement costs by 40%.?? For devices that rely on long battery life, this design is critical to avoiding frequent maintenance.

How does the 1A output current benefit multi-sensor IoT modules?

Many IoT modules use 3?C4 low-power sensors (e.g., temperature, humidity, motion) that draw 0.2A?C0.3A each, totaling 0.6A?C1.2A. Low-current converters (??600mA) can??t power these arrays alone, forcing parallel converters that add cost and space. The ST1S10PHR??s 1A output handles 4x 0.2A sensors with one chip. An IoT module designer shared ??we used to need two 600mA converters; now we use one, cutting PCB space by 40% and reducing our Bill of Materials by 30%.??

Can the ST1S10PHR handle input voltage fluctuations from batteries?

Yes. Its 2.7V?C5.5V input range easily handles voltage changes from common batteries-e.g., 3.7V lithium-ion batteries (which discharge from 4.2V to 2.7V) or 4x AA alkaline batteries (which drop from 6V to 4V, safe for regulated 5V inputs). The converter maintains stable output voltage even as input drops, 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 converter-adding 3 weeks of runtime.??

What is the benefit of ultra-low quiescent current for standby-mode sensors?

Many IoT sensors spend 99% of their time in standby (e.g., sampling data once per minute), so quiescent current (power used when idle) dominates battery life. The ST1S10PHR??s 15??A quiescent current is 70% lower than 50??A alternatives, drastically reducing standby power use. A wireless environmental monitor engineer noted ??our monitor uses 15??A in standby vs. 50??A before-this cut standby power use by 70%, extending battery life from 12 months to 20 months.?? For low-duty-cycle devices, this feature is a key driver of long battery life.

How does built-in voltage ripple filtering improve sensor accuracy?

Precision sensors (e.g., industrial pressure sensors, medical glucose sensors) are sensitive to voltage ripple-even 50mV ripples can cause 5?C10% data errors. The ST1S10PHR??s built-in filtering limits ripple to ??20mV peak-to-peak, ensuring stable power for sensors. An industrial engineer confirmed ??our pressure sensors had 8% error with a non-filtered converter; with the ST1S10PHR, error dropped to 0.5%-meeting our clients?? strict accuracy requirements.?? This eliminates the need for external capacitors, saving space and cost.