Time (s)

Discontinuous Conduction Mode (DCM)

IPeak

Time (s)

Time (s)

Time (s)

Time (s)

Discontinuous Conduction Mode (DCM)

DCM - CCM Boundary

Continuous Conduction Mode (CCM)

Continuous Conduction Mode (CCM)

VIN

IAVERAGE

IAVERAGE

VIN

LM20145

SNVS530E – OCTOBER 2007 – REVISED MARCH 2013

www.ti.com

Figure 25. Modes of Operation for LM20145

Design Guide

This section walks the designer through the steps necessary to select the external components to build a fully

functional power supply. As with any DC-DC converter numerous trade-offs are possible to optimize the design

for efficiency, size, or performance. These will be taken into account and highlighted throughout this discussion.

To facilitate component selection discussions the circuit shown in Figure 26 below may be used as a reference.

Unless otherwise indicated all formulas assume units of amps (A) for current, farads (F) for capacitance, henries

(H) for inductance and volts (V) for voltages.

12

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