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SNVU518 – April 2016
Copyright © 2016, Texas Instruments Incorporated
LM5175RHF (QFN) EVM User Guide
User's Guide
SNVU518 – April 2016
LM5175RHF (QFN) EVM User Guide
1
High Density EVM Description
The LM5175RHFEVM-HD demonstrates a compact buck-boost design using the LM5175 high
performance 4-switch buck-boost controller. This evaluation module is designed to operate with input
voltage from 5 V to 42 V and provide a regulated 12 V output with load current up to 6 A. The transition
region control method of the LM5175 maintains high efficiency over the entire operating input voltage in
contrast with a conventional four-switch buck-boost converter which has a drop in efficiency at V
IN
close to
V
OUT
. The switching frequency is set at 400 kHz and can be synchronized to an external clock signal. The
board specifications are listed in
Table 1. Board Specifications
Parameter
Value
Input Voltage (V
IN
)
5.5V to 42V (45V transient)
Output Voltage (V
OUT
)
12V
Maximum Output Current (I
OUT
)
6A
Default Switching Frequency (f
sw
)
400 kHz
Synchronizable Frequency Range
Up to 600 kHz
Efficiency (I
OUT
= 5A, V
IN
= 6V to 36V)
95.1% to 98.4%
Board Size (6 layers)
50 mm x 43 mm
(1.98 in x 1.7 in)
1.1
Additional Features
•
Smooth Buck-Boost Operation
•
Ultra-high (>98%) peak power conversion efficiency
•
High power density compact design
•
Adjustable output voltage using TRIM
•
Resistor programmable switching frequency (adjustable) with optional external synchronization (SYNC)
up to 600 kHz
•
Cycle-by-cycle overcurrent protection via shunt resistor current sensing
•
Optional hiccup mode overload protection (off by default)
•
Default forced PWM (CCM) fixed switching operation with option to set diode emulation mode (DCM)
•
Programmable V
IN
UVLO threshold and hysteresis
•
Spread spectrum dither option for reduced EMI
•
Power Good indicator
•
Input circuit damping and energy storage provided by bulk electrolytic capacitor
•
Easy access to PGOOD, ENABLE, TRIM and SYNC using conveniently located test points
