Wide input voltage range synchronous DC-DC step-down controller features extreme voltage conversion ratio over switching frequency range for improved efficiency, thermals, and ripple performance

This feature-rich buck converter includes a Power Good output useful for monitoring and output voltage sequencing for digital ICs during the power-up phase. Embedded protections ensure controlled and safe operation for critical environments in telecom, networking and industrial applications.

Available in a 20-lead QFN mm package with wettable flanks, its embedded gate driver minimizes the number of external components, lowering BOM costs.

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 techinal bulletin


This article describes a synchronous step-down controller application for the telecom sector and can also be used as a guideline for applications in other sectors. The solution is based on our L3751 synchronous buck controller coupled with the ZC1818 shielded power inductor from Coilcraft for a 60 to 12 V conversion with an output current of 10 to 15 A and delivering up to 180W.

Key features

10 year longevity
  • Wide 6 to 75 V input voltage range
  • Adjustable output voltage from 0.8 to 60V
  • 100 kHz to 1 MHz switching frequency range
  • 40 nsec minimum on-time for extreme duty ratio
  • Internal voltage monitoring
  • Thermal protection
  • Operating junction temperature range: -40 to 150°C

Application examples

 Telecom, networking and industrial applications Telecom, networking and industrial applications
 Failsafe systems Failsafe systems
 Unregulated 24V and 48V input voltage bus Unregulated 24V and 48V input voltage bus
 Conversion from high voltage battery to 12V and 5V rail Conversion from high voltage battery to 12V and 5V rail

Recommended resources

steval l3751v12

This flexible buck converter evaluation board provides a regulated 5 V output at 230 kHz switching frequency with a configurable output voltage and current limit. Compliant with CISPR 16-4-2 standards, the board includes an input filter to reduce EMI.

stsw edsim

Our easy-to-use interactive eDesign tool simplifies designers’ lives! A fast, powerful electrical simulation tool for SMPS and analog ICs featuring enhanced accuracy, eDSim is 10 to 50 times faster than traditional analog SPICE simulators.

dc dc converter pdf

This guide provides developers with an overview of our most commonly used switching regulators and will help identify the most appropriate solution for each type of application.

 The 6V to 75V synchronous buck controller : L3751 

Looking for a synchronous step-down switching controller with extreme conversion ratios for virtually any application? Start by simulating and analyzing L3751 performance in your industrial bus, telecom & networking, and many other applications. 




ウェッタブル・フランク付きの20リードQFN mmパッケージで提供される、本製品の組込みのゲート・ドライバは、外部コンポーネント数を最小限に抑えることで、部品(BOM)コストを低減します。

Key features

10 year longevity
  • 幅広い6V~75Vの入力電圧範囲
  • 0.8V~60Vの範囲で調整可能な出力電圧
  • 100kHz~1MHzのスイッチング周波数範囲
  • 40nsecの最小オン時間で、非常に高いデューティ比を実現
  • 内部電圧監視
  • 過熱保護
  • 動作温度範囲:-40℃~+150℃


通信 / ネットワーキング / 産業用アプリケーション


steval l3751v12

この柔軟性の高い降圧コンバータ評価ボードは、設定可能な出力電圧および電流制限とあわせて、230kHzのスイッチング周波数で安定化された5V出力を提供します。CISPR 16-4-2規格に準拠した本ボードには、EMIを低減する入力フィルタが内蔵されています。

stsw edsim


dc dc converter pdf