STMicroelectronics L4971D Buck Regulator, TO220 Package for Industrial & Energy Systems

STMicroelectronics L4971D Synchronous Buck Regulator Overview

The STMicroelectronics L4971D is a rugged, high-performance synchronous step-down (buck) regulator engineered for heavy-duty B2B power management-including Industrial Automation drives, Energy and Power systems (solar inverters, energy storage), and large-scale Internet of Things (IoT) infrastructure. Designed to convert an 8V?C40V wide input voltage range to an adjustable 1.2V?C30V output (with 3A continuous current capacity), it delivers stable power to high-load components like industrial motor controllers, solar inverter gate drivers, and energy storage system (ESS) battery management modules. Integrating a synchronous rectifier, pulse-width modulation (PWM) control, overcurrent protection, thermal shutdown, and short-circuit protection into a durable TO220 through-hole package, it operates reliably across -40??C to +150??C-making it a top choice for engineers prioritizing adjustability, high current handling, and thermal resilience in industrial-grade power designs.

As a flagship product from STMicroelectronics-a global leader in semiconductor solutions for industrial and energy sectors with 30+ years of expertise-the L4971D meets strict quality standards (RoHS 2 compliance, ISO 9001 certification, and AEC-Q100 Grade 3 qualification) and undergoes 1,000+ hours of durability testing. Senior engineers at a leading industrial automation firm endorse it, noting: ??The L4971D??s 95% efficiency and wide input range let us power 3 different motor drives with one chip, while its TO220 package eliminates extra cooling fans.?? For more reliable industrial and energy-focused ICs, visit IC-fabrikant.

Technical Parameters of STMicroelectronics L4971D

Key Technical Features of L4971D Buck Regulator

• Adjustable 1.2V?C30V output, eliminating the need for multiple fixed-voltage regulators and reducing component count by 65%. An industrial automation engineer reported: ??This feature lets us power 3 components (5V PLC, 12V sensor, 24V relay) with one chip-saving 35% PCB space and 45% assembly time for control panels.??
• 8V?C40V wide input range, accommodating industrial 12V/24V supplies, solar 24V/36V arrays, and ESS 40V batteries without external voltage clamping. A solar inverter designer noted: ??We use the same regulator across 24V residential and 36V commercial inverters-standardizing inventory and cutting part SKUs by 60%.??
• TO220 package with metal heat tab, delivering 50% better heat dissipation than QFN10 packages at 3A load. Industrial motor control teams confirm: ??This package keeps the regulator 38??C cooler at full load, eliminating active cooling in motor drives-saving 25% space in factory control cabinets.??
• 95% peak efficiency, minimizing energy loss in grid-connected and battery-powered systems. An ESS engineer shared: ??This efficiency extends our backup battery life by 40%-from 10 hours to 14 hours during outages-critical for industrial clients needing uninterrupted production power.??
• ??20mV_pp low output ripple, preventing signal interference for noise-sensitive components like industrial DACs and solar inverter current sensors. A power systems firm noted: ??This ripple reduced grid synchronization errors by 99.6%, ensuring our inverters meet utility standards without extra filtering-saving 20% component cost.??

Advantages of L4971D vs. Typical Alternative Power Regulators

Compared to low-efficiency linear regulators, smaller-package buck regulators (e.g., QFN10), and fixed-output power ICs, the L4971D delivers three critical benefits for B2B industrial and energy power designs-backed by real customer feedback:

First, its 95% efficiency outperforms linear regulators. Linear regulators for 5V outputs max out at 73% efficiency, wasting 27% of energy as heat. The L4971D??s synchronous design cuts this loss to 5%. A solar energy firm explained: ??Our old linear regulator wasted 3.1W at 2A load-this converter wastes just 0.1W. For 1,000 inverters, that??s a 3,000W daily energy savings and 5.5% more solar energy fed to the grid annually.??

Second, its TO220 package solves thermal challenges vs. smaller alternatives. QFN10 packages overheat at 3A load, requiring fans or large heat sinks that add size and cost. The TO220??s metal tab dissipates heat 50% better, eliminating extra cooling. An industrial motor firm confirmed: ??Our old QFN10 regulator hit 150??C at 3A, triggering motor shutdowns; this TO220 stays at 112??C-well below its 150??C max. We removed the cooling fan, cutting drive power use by 28% and weight by 18%.??

Third, its adjustable output outperforms fixed-output regulators. Fixed-output ICs require 3 separate parts to power 5V/12V/24V components-adding inventory complexity and failure points. The L4971D??s 1.2V?C30V range eliminates this. An IoT infrastructure designer shared: ??We use one part for our 5V sensor hubs and 24V communication modules-cutting part count by 55% and simplifying supply chain management. This also reduced engineering time for new IoT models by 30%.??

Typical Applications of STMicroelectronics L4971D

The L4971D is engineered to solve high-efficiency, adjustable-voltage power challenges-with proven success in these key B2B use cases:

• Energie en vermogen (zonne-omvormers): Converting 24V/36V solar panel power to 5V for inverter control units. A solar firm confirmed: ??95% efficiency cuts energy loss, and wide input range handles low-light voltage dips-solar energy harvest improved by 5.5% annually vs. old regulators.??
• Industriële automatisering (motoraandrijvingen): Regulating 24V factory power to 12V for motor drive ICs and 5V for position sensors. A factory operator noted: ??3A current handles peak loads, and low ripple reduces drive errors-motor uptime improved to 99.99% vs. 99.5% with old regulators.??
• Energie en vermogen (energieopslagsystemen): Step-down 40V battery power to 3.3V for ESS monitoring modules. An ESS provider reported: ??TO220 package handles heat, and high efficiency extends backup life by 40%-clients now get 14 hours of backup vs. 10 before.??
• Internet of Things (IoT) zware hubs: Regulating 24V industrial power to 5V for 8 high-load sensors and 12V for Wi-Fi modules. An IoT provider noted: ??Adjustable output cuts part count by 55%, and 95% efficiency extends hub battery life by 35%-maintenance intervals doubled from 2 to 4 months.??
• Test and Measurement (Portable Calibrators): Converting 12V battery power to 5V/9V for precision test circuits. A test equipment maker shared: ??Wide input range fits 8V?C12V sources, and ??1.4% output accuracy ensures calibration reliability-tool error rates dropped by 98% vs. fixed-output regulators.??

Frequently Asked Questions (FAQ) About L4971D

Why is adjustable output critical for industrial control panels?

Industrial control panels power multiple components (5V PLCs, 12V sensors, 24V relays) that require different voltages. Fixed-output regulators need 3 separate chips, but the L4971D??s 1.2V?C30V range powers all with one. An automation engineer noted: ??This cuts component count by 65%, saving 35% PCB space-critical for compact control panels. Fewer parts also reduce failure risks by 75%, ensuring 24/7 factory operation without unexpected downtime.??

Wat zijn de voordelen van het TO220-pakket voor de regeling van omvormers voor zonne-energie?

Solar inverters generate intense heat from sun exposure and 3A continuous operation, and small packages like QFN10 overheat quickly. The TO220??s metal tab dissipates heat 50% better, keeping temperatures safe. A solar designer shared: ??Our old QFN10 regulator hit 150??C in direct sunlight, stopping the inverter; this TO220 stays at 112??C. We removed the cooling fan, cutting inverter power use by 28% and making it easier to fit in residential rooftop enclosures.??

Can the L4971D operate with low-voltage industrial backup generators?

Yes. Its 8V?C40V input range handles 8V?C12V backup generator outputs (common in small factories) while maintaining stable output. An industrial plant manager confirmed: ??Our backup generator dips to 8.4V during startup; this regulator keeps the PLC and sensors powered, eliminating 99.7% of generator-related production halts. We no longer need a separate voltage booster, saving 32% space in our control cabinet.??

What value does low output ripple add for industrial motor drives?

Industrial motor drives rely on precise voltage signals to control speed and position-high ripple causes erratic motor behavior, leading to product defects. The L4971D??s ??20mV_pp ripple eliminates this. A manufacturing engineer noted: ??Our old regulator??s 95mV ripple caused 15% of parts to be out of tolerance; this model cuts ripple by 79%, ensuring 99.9% part accuracy. This reduced scrap costs by $52,000 annually for our production line.??

Hoe helpt een breed ingangsbereik IoT-hubs met meerdere voedingsbronnen?

Industrial IoT hubs use diverse power sources-24V factory mains, 12V batteries for portability, and 40V ESS backups. The 8V?C40V range handles all without external adapters. An IoT deployment firm shared: ??This lets us use the same hub across 4 factory zones, standardizing inventory and cutting logistics costs by 45%. We also avoid designing 4 separate power circuits, saving 28% engineering time for new hub models.??