Application Report
SLVA343A–June 2009–Revised May 2010
Medium Integrated Power Solution Using a Dual DC/DC
Converter and an LDO
Ambreesh Tripathi.......................................................................... PMP - DC/DC Low-Power Converters
ABSTRACT
This reference design is intended for users designing with the TMS320C6742, TMS320C6746,
TMS320C6748, or OMAP-L138 processor. Using sequenced power supplies, this reference design
describes a system having a 3.3-V input voltage and a high-efficiency dc/dc converter with integrated
FETs for a small, simple design.
Sequenced power supply architectures are becoming commonplace in high-performance microprocessor
and digital signal processor (DSP) systems. To save power and increase processing speeds, processor
cores have smaller geometry cells and require lower supply voltages than the system bus voltages. Power
management in these systems requires special attention. This application report addresses these topics
and suggests solutions for output voltage sequencing.
Contents
1 Introduction .................................................................................................................. 2
2 Power Requirements ....................................................................................................... 2
3 Features ...................................................................................................................... 3
4 Bill of Materials .............................................................................................................. 6
List of Figures
1 PMP4978 Reference Design Schematic................................................................................. 4
2 Optional Circuit for DVDD_A, DVDD_B and DVDD_C................................................................. 5
3 Sequencing in Start-up Waveform........................................................................................ 7
4 Efficiency V
OUT2
= 1.8 V..................................................................................................... 7
5 Efficiency V
OUT1
= 1.1 V..................................................................................................... 7
List of Tables
1 Power Requirements ....................................................................................................... 2
2 PMP4978 Bill of Materials ................................................................................................. 6
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SLVA343A–June 2009–Revised May 2010 Medium Integrated Power Solution Using a Dual DC/DC Converter and an LDO
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