LM3743 High-Performance Synchronous Buck Controller with Comprehensive Fault Protection Features | TI.com

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High-Performance Synchronous Buck Controller with Comprehensive Fault Protection Features



The LM3743 is a DC-DC voltage mode PWM buck controller featuring synchronous rectification at 300 kHz or 1 MHz. It can deliver current as high as 20A and step down from an input voltage between 3V and 5.5V down to a minimum output voltage of 0.8V, with a ±1.75% internal reference accuracy. The LM3743 provides a set of comprehensive fault protection features such as high-side current limit, output under-voltage protection, and low-side current limit. When any of these fault protection features are engaged, it enters a hiccup protection mode which is suitable for high reliability systems such as rack mounted servers and telecom base station subsystems. The LM3743 also employs a proprietary monolithic glitch free pre-bias start-up method suited for FPGA and ASIC logic devices. An external programmable soft-start allows for tracking and timing flexibility. The driver features 1.6Ω of pull-up resistance and 1Ω of pull-down drive resistance for high power density and very efficient power processing.


  • Input Voltage From 3.0V to 5.5V
  • Output Voltage Adjustable Down to 0.8V
  • Reference Accuracy: ±1.75%, over Full Temperature and Input Voltage Range
  • High-Side and Low-Side N-Channel MOSFETs
  • Switching Frequency Options of 1 MHz or 300 kHz
  • Comprehensive Fault Protection Features:
    • High-Side Current Limit
    • Low-Side Current Limit
    • Output Under-Voltage Protection
  • Hiccup Mode Protection Eliminates Thermal Runaway During Fault Conditions
  • Externally Programmable Soft-Start with Tracking Capability
  • Pre-Bias Start-Up Capability
  • VSSOP-10 Package

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Part number Order Vin (Min) (V) Vin (Max) (V) Vout (Min) (V) Vout (Max) (V) Iout (Max) (A) Regulated outputs (#) Number of Phases Switching frequency (Min) (kHz) Switching frequency (Max) (kHz) Iq (Typ) (mA) Features Duty cycle (Max) (%) Operating temperature range (C) Rating Package Group Type Control mode
LM3743 Order now 3     5.5     0.8     4.6     10     1     1     300     1000     1.8     Enable
Pre-Bias Start-Up
91     -40 to 125     Catalog     VSSOP | 10     Controller     Voltage Mode