LM3753 Datasheet, PDF (1/38 Pages) National Semiconductor (TI) – Scalable 2-Phase Synchronous Buck Controllers with Integrated FET Drivers and Linear Regulator Controller

LM3753/54
December 14, 2009
Scalable 2-Phase Synchronous Buck Controllers with
Integrated FET Drivers and Linear Regulator Controller
General Description
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 con-
trollers 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.
The LM3753 supports a Tracking function, while the LM3754
supports adjustable Soft-Start. The LM3753 Tracking is al-
ways enabled, so the output is controlled both up and down.
The Soft-Start function on the LM3754 can only drive the out-
put upwards – it will not pull it down, therefore, pre-biased
loads will not be discharged. Available in the 5 mm x 5 mm
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 200 kHz to 1 MHz}
■ ^{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 50 ns}
■ ^{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}
Simplified Application
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