Texas Instruments Evaluation Board for the LM25118 Wide Vin Buck-Boost Controller LM25118EVAL/NOPB LM25118EVAL/NOPB Datenbogen
Produktcode
LM25118EVAL/NOPB
User's Guide
SNVA614B – January 2012 – Revised January 2014
AN-2205 LM25118 Evaluation Board
1
Introduction
The LM25118 Evaluation Board is designed to provide the design engineer with a fully functional,
Emulated Current Mode Control, buck-boost power converter to evaluate the LM25118 controller IC. The
evaluation board provides a 12 V output with 3 A of output current capability. The evaluation board’s wide
input voltage range is from 42 V to 5 V, with operation down to 3 V with some component changes. The
evaluation board operates at 300 kHz, a good compromise between conversion efficiency, tradeoffs
between buck and buck-boost mode requirements, and converter size. The printed circuit board consists
of 4 layers with 2 ounce copper top and bottom, and 1 ounce copper on internal layers. The board is
constructed with FR4 material. This user' guide contains the evaluation board schematic, bill-of-materials
(BOM) and a quick setup procedure. For more complete circuit and design information, see the
LM25118/LM25118Q Wide Voltage Range Buck-Boost Controller (
Emulated Current Mode Control, buck-boost power converter to evaluate the LM25118 controller IC. The
evaluation board provides a 12 V output with 3 A of output current capability. The evaluation board’s wide
input voltage range is from 42 V to 5 V, with operation down to 3 V with some component changes. The
evaluation board operates at 300 kHz, a good compromise between conversion efficiency, tradeoffs
between buck and buck-boost mode requirements, and converter size. The printed circuit board consists
of 4 layers with 2 ounce copper top and bottom, and 1 ounce copper on internal layers. The board is
constructed with FR4 material. This user' guide contains the evaluation board schematic, bill-of-materials
(BOM) and a quick setup procedure. For more complete circuit and design information, see the
LM25118/LM25118Q Wide Voltage Range Buck-Boost Controller (
) data sheet and quick start.
The performance of the evaluation board is as follows:
•
Input Range: 42 V to less than 5 V at Full Current
•
Operation to 3 V at Reduced Current and Appropriate Adjustments*
•
Output Voltage: 12 V
•
Output Current: 0 to 3 A
•
Frequency of Operation: 300 kHz
•
Board Size: 3.45 X 2.65 inches
•
Load Regulation: 1%
•
Line Regulation: 0.1%
•
Over-Current Limiting
•
Operation with V
IN
Greater or Less than V
OUT
*Operation at full current to around 3 V is possible with current limit sense resistor, UVLO threshold, and
corresponding C
corresponding C
ramp
adjustment. Additional input capacitance may be required. For more details, see the
LM25118/LM25118Q Wide Voltage Range Buck-Boost Controller (
) data sheet.
2
IC Features
•
Integrated High and Low Side Driver
•
Internal High Voltage Bias Regulator
•
Wide Input Voltage Range: 5 V to 42 V
•
Emulated Current Mode Control
•
Single Inductor Architecture
•
V
OUT
Operation below and above V
IN
•
Single Resistor Sets Oscillator Frequency
•
Oscillator Synchronization Capability
•
Programmable Soft-Start
•
Ultra Low (<10 µA) Shutdown Current
•
Enable Input
•
Wide Bandwidth Error Amplifier
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1
SNVA614B – January 2012 – Revised January 2014
AN-2205 LM25118 Evaluation Board
Copyright © 2012–2014, Texas Instruments Incorporated