LTM4618EVPBF datasheet(9/24 Pages) LINER

9 / 24 page

LTM4618

4618f

OPERATION

Power Module Description

The LTM4618 is a standalone non-isolated switching mode

DC/DC power supply. It can deliver up to 6A (DC current)

output with few external input and output capacitors. This

module provides precisely regulated output voltages pro-

grammable via external resistors from 0.8VDC to 5.0VDC

over 4.5V to 26.5V input voltages. The typical application

schematic is shown in Figure 21. For ≤6V inputs, connect

VIN, INTVCC and EXTVCC together.

The LTM4618 has an integrated constant frequency current

mode regulator and built-in power MOSFET devices with

fast switching speed. The typical switching frequency is

750kHz.

With current mode control and internal feedback loop

compensation, the LTM4618 module has sufﬁcient stabil-

ity margins and good transient performance with a wide

range of output capacitors, even with all ceramic output

capacitors.

Current mode control provides cycle-by-cycle fast current

limit and current foldback in a short-circuit condition. Pull-

ing the RUN pin below 1.1V forces the controller into its

shutdown state, by turning off both MOSFETs. The TK/SS

pin can be used for programming the output voltage ramp

and voltage tracking during start-up. See the Applications

Information section.

The LTM4618 is internally compensated to be stable over

all operating conditions. The Linear Technology μModule

Power Design Tool will be provided for transient and

stability analysis. The VFB pin is used to program the

output voltage with a single external resistor to ground.

Multiphase operation can be easily employed with the

synchronization control.

High efﬁciency at light loads can be accomplished with

selectable Burst Mode or pulse-skipping mode operations

using the MODE/PLLIN pin. Efﬁciency graphs are provided

for light load operation in the Typical Performance Char-

acteristics section.

LTM4618EVPBF Datasheet(PDF) 9 Page - Linear Technology