LM3753/54 Scalable 2-Phase Synchronous Buck Controllers


National Semiconductor's integrated FET drivers and linear regulator controllers from the PowerWise® family

National Semiconductor's The LM3753 and LM3754 are full-featured, single-output, dual-phase, voltage-mode synchronous PWM buck controllers. They can be configured to control from 2 to 12 interleaved power stages, creating a single high power output. Both controllers utilize voltage-mode control with input voltage feed-forward for high noise immunity. An internal average current loop forces real-time current sharing between phases during load transients.    LM3753/54 Datasheet
National Semiconductor LM3753/54 Scalable 2-Phase Synchronous Buck Controllers

  • Overview
  • Features & Applications
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Overview

The LM3753 supports a Tracking function, while the LM3754 supports adjustable Soft-Start. The LM3753 Tracking is always enabled, so the output is controlled both up and down. The Soft-Start function on the LM3754 can only drive the output upwards – it will not pull it down. Therefore, pre-biased loads will not be discharged. It is available in the 5mm x 5mm thermally enhanced 32-lead LLP package with a thermal pad.


Features
  • Wide input voltage range of 4.5V to 18V
  • Up to 12 channels for 300A load
  • System accuracy better than 1%
  • 0.6V to 3.6V output voltage range
  • Switching frequency from 200kHz to 1MHz
  • Phase current sharing ±12% max over temperature
  • Integrated 4.35V ±2.3% LDO
  • Inductor DCR or sense resistor current sensing
  • Interleaved switching for low I/O ripple current
  • Integrated synchronous NFET drivers
  • Programmable Soft-Start (LM3754) or Tracking (LM3753)
  • Pre-biased startup (LM3754)
  • Output voltage differential remote sensing
  • Minimum controllable on-time of only 50ns
  • Programmable Enable and input UVLO
  • Power Good flag
  • OVP, UVP and hiccup over-current protection

Applications
  • CPUs, GPUs (graphic cards), ASICs, FPGAs, large memory arrays, DDR
  • High current POL converters
  • Networking systems
  • Power distribution systems
  • Telecom/datacom DC/DC converters
  • Desktops, servers, and workstations

  • RoHS Compliant


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 Available in Tape & Reel (TR-ND), Cut Tape (CT-ND), and custom Digi-Reel® (DKR-ND)
Digi-Key
Part Number
National Semiconductor
Part Number
    Description
LM3753SQ/NOPB
    LM3753 supports a Tracking function
LM3754SQ/NOPB
    LM3754 supports adjustable Soft-Start