Buck controllers (external switch)

Achieve high reliability in high-power, thermally-demanding applications

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DC/DC step-down (buck) controllers with external FETs help you optimize your power supply for even the most challenging requirements. With buck controllers, you can reach levels of output power, operating temperature range and voltage step-down ratios with your power-supply design, that are simply not possible with converters or power modules.

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Select by input voltage range

Battery, 3.3 V

Buck controllers that typically take an Input voltage from batteries, supercapacitors (2.7 V or higher) or PCI Express connectors (3.3 V).

12 V

Buck controllers commonly found in automotive, server, communication systems or a supercapacitor output found in storage and UPS applications.

19 V or 24 V

Buck controllers for industrial and automotive systems with nominal 24-V input rails or PCB systems with a nominal 19-V input rail.

48 V

Buck controllers designed for 48-V input buses found in industrial, automotive and communications applications.

Multiphase

Multiphase buck-controller applications typically involve high-output current, low-output voltage and tight voltage regulation required for ASIC, FPGA, DDR, DSP and CPU core rails.

LM5149-Q1 NEW

80-V automotive synchronous buck DC/DC controller with ultra-low IQ and integrated active EMI filter

Approx. price (USD) 1ku | 1.947
TPS536C5 NEW

12-phase, step-down, digital multiphase controller with SVI3 and PMBus for AMD platform

Approx. price (USD) 1ku | 7.7
TPS53685 NEW

Eight-phase, step-down, digital multiphase controller with SVI3 and PMBus for AMD platform

Approx. price (USD) 1ku | 4.787
LM25143-Q1 NEW

Automotive, 3.5-V to 42-V low-Iq, dual output, stackable synchronous buck DC-DC controller

Approx. price (USD) 1ku | 1.562
LM5143A-Q1 NEW

Automotive, 3.5-V to 65-V low-IQ, dual output, stackable synchronous buck DC-DC controller

Approx. price (USD) 1ku | 1.953
LM5143 NEW

3.5-V to 65-V, dual-output, stackable, synchronous buck DC/DC controller with ultra-low IQ

Approx. price (USD) 1ku | 1.655

Power trends

Low EMI

Mitigating buck converter EMI is a major challenge for many power supply designers. Devices with built-in EMI reduction technologies save design time and headaches and help you comply with difficult standards like CISPR 25 Class-5. Take a look at our portfolio below for some of the latest and best DC/DC step-down controllers for excellent EMI performance. 

Technical article
How to reduce EMI and shrink power-supply size with an integrated active EMI filter
Learn how an active EMI filter (AEF) can reduce passive filter size by 50%, saving you PCB area and solution cost.
Application note
Improve DC/DC Regulator EMI for Free with Optimized Power Stage Layout
This tech note explores EMI abatement in high-current DC/DC regulator circuits that employ a controller paired with discrete high-side and low-side silicon power MOSFETs. 
PDF
Video
Reducing filter size and cost with an active EMI filter
See how the power of integration can not only reduce your filter size and volume, but cost and EMI. This video explains our integrated active EMI filtering technology (AEF), and how it can be used to reduce power supply size.
Featured products for low EMI
LM25149-Q1 PREVIEW 42-V automotive synchronous buck DC/DC controller with ultra-low IQ and integrated active EMI filter
LM5143-Q1 ACTIVE 3.5-V to 65-V low Iq, dual, 2-phase synchronous buck DC-DC controller
LM5141 ACTIVE Low Iq, Wide Input Range Synchronous Buck Controller
Low quiescent current (IQ)

DC/DC buck switching regulators with ultra-low standby quiescent current increase light-load efficiency and extend battery life in portable and battery-operated applications. Find some of the lowest IQ devices in our buck controller portfolio below.

White paper
Demystifying Input Supply Current in DC/DC Regulators:From Shutdown to Full Load
This paper sets out to clear up some of the confusion surrounding quiescent current by focusing on the current required from the input supply flowing into a buck regulator, rather than getting caught up in the terminology.
PDF
Video
How to extend battery life with low quiescent current technologies
What is quiescent current and why does it matter? Get the answers to these questions and much more in this training series. 
Featured products for low quiescent current (IQ)
LM5143-Q1 ACTIVE 3.5-V to 65-V low Iq, dual, 2-phase synchronous buck DC-DC controller
LM25141 ACTIVE Low Iq, Wide Input Range Synchronous Buck Controller
LM25149-Q1 PREVIEW 42-V automotive synchronous buck DC/DC controller with ultra-low IQ and integrated active EMI filter

Design & development resources

Design tool
WEBENCH® Power Designer
WEBENCH® Power Designer creates customized power-supply circuits based on your requirements. The environment gives you end-to-end power-supply design capabilities that save you time during all phases of the design process.
Simulation tool
PSpice® for TI design and simulation tool
PSpice® for TI is a design and simulation environment that helps evaluate functionality of analog circuits. This full-featured, design and simulation suite uses an analog analysis engine from Cadence®. Available at no cost, PSpice for TI includes one of the largest model libraries in the (...)
Design tool
Power Stage Designer™ Tool of Most Commonly Used Switch-mode Power Supplies
Power Stage DesignerTM is a JAVA-based tool (requires JAVA 8 or OpenJDK 8) that helps engineers accelerate their power-supply designs by calculating voltages and currents of 20 topologies according to the user’s inputs. Additionally, Power Stage Designer contains a Bode plotting tool and a (...)

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