LTM4601HVIVPBF Datasheet, PDF (10/30 Pages) Linear Dimensions Semiconductor – 12A 28VIN DC/DC μModule Regulator with PLL, Output Tracking and Margining

LTM4601HV
OPERATION
Power Module Description
The LTM4601HV is a standalone nonisolated switching
mode DC/DC power supply. It can deliver up to 12A of
DC output current with some external input and output
capacitors. This module provides a precisely regulated
output voltage programmable via one external resistor
from 0.6V_DC to 5.0V_DC over a 4.5V to 28V wide input
voltage. The typical application schematics are shown in
Figures 19 and 20.
The LTM4601HV has an integrated constant on-time
current mode regulator, ultralow R_DS(ON) FETs with fast
switching speed and integrated Schottky diodes. The typical
switching frequency is 850kHz at full load. With current
mode control and internal feedback loop compensation,
the LTM4601HV module has sufficient stability margins
and good transient performance under a wide range of
operating conditions and with a wide range of output
capacitors, even all ceramic output capacitors.
Current mode control provides cycle-by-cycle fast current
limit. Besides, foldback current limiting is provided in an
overcurrent condition while V_FB drops. Internal overvolt-
age and undervoltage comparators pull the open-drain
PGOOD output low if the output feedback voltage exits a
±10% window around the regulation point. Furthermore,
in an overvoltage condition, internal top FET Q1 is turned
off and bottom FET Q2 is turned on and held on until the
overvoltage condition clears.
Pulling the RUN pin below 1V forces the controller into its
shutdown state, turning off both Q1 and Q2. At low load
current, the module works in continuous current mode by
default to achieve minimum output voltage ripple.
When DRV_CC pin is connected to INTV_CC an integrated
5V linear regulator powers the internal gate drivers. If a
5V external bias supply is applied on the DRV_CC pin, then
an efficiency improvement will occur due to the reduced
power loss in the internal linear regulator. This is especially
true at the high end of the input voltage range.
The LTM4601HV has a very accurate differential remote
sense amplifier with very low offset. This provides for very
accurate output voltage sensing at the load. The MPGM
pin, MARG0 pin and MARG1 pin are used to support
voltage margining, where the percentage of margin is
programmed by the MPGM pin, and MARG0 and MARG1
select margining.
The PLLIN pin provides frequency synchronization of the
device to an external clock. The TRACK/SS pin is used
for power supply tracking and soft-start programming.
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