LTM4611(RevB) Ver la hoja de datos (PDF) - Linear Technology
Número de pieza
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Fabricante
LTM4611 Datasheet PDF : 30 Pages
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LTM4611
Operation
Power Module Description
The LTM4611 is a high performance single output stand-
alone nonisolated switching mode DC/DC power supply.
It can provide a 15A output with few external input and
output capacitors. This module provides precisely regu-
lated output voltages programmable via external resistors
from 0.8VDC to 5VDC over a 1.5V to 5.5V input range. The
typical application schematic is shown in Figure 21.
The LTM4611 has an integrated constant-frequency cur-
rent mode regulator, power MOSFETs, 0.2µH inductor
and other supporting discrete components. The nominal
switching frequency range is from 330kHz to 780kHz, and
the default operating frequency is 500kHz. For switching
noise-sensitive applications, it can be externally syn-
chronized from 360kHz to 710kHz. See the Applications
Information section.
With current mode control and internal feedback loop
compensation, the LTM4611 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 in an overcurrent condition. An internal overvoltage
monitor protects the output voltage in the event of an
overvoltage >7.5%. The top MOSFET is turned off and the
bottom MOSFET is turned on until the output is cleared.
Pulling the RUN pin below 1.1V forces the regulator into a
shutdown state. The TRACK/SS pin is used for program-
ming the output voltage ramp and voltage tracking during
start-up. See the Application Information section.
The LTM4611 is internally compensated to be stable over
all operating conditions. Table 5 provides a guideline for
input and output capacitances for several operating con-
ditions. 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.
A remote sense amplifier is provided for accurately sensing
output voltages ≤3.7V at the load point.
Multiphase operation can be easily employed with the
synchronization inputs using an external clock source.
See the Typical Applications.
High efficiency at light loads can be accomplished with
selectable Burst Mode operation using the MODE_PLLIN
pin. These light-load features will accommodate battery
operation. Efficiency graphs are provided for light-load
operation in the Typical Performance Characteristics
section.
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For more information www.linear.com/LTM4611
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