9 Application and Implementation

Note

Information in the following applications sections is not part of the TI component specification,

and TI does not warrant its accuracy or completeness. TI’s customers are responsible for

determining suitability of components for their purposes, as well as validating and testing their design

implementation to confirm system functionality.

9.1 Application Information

The LM5013 requires only a few external components to step down from a wide range of supply voltages

to a fixed output voltage. Several features are integrated to meet system design requirements, including the

following:

• Precision enable

• Input voltage UVLO

• Internal soft start

• Programmable switching frequency

• A PGOOD indicator

To expedite the process of designing with LM5013, a LM5013 design calculator is available on the product folder

"tool" section. This calculator is complemented by an evaluation module for order, PSPICE models, as well as

TI's WEBENCH® Power Designer.

9.2 Typical Application

Figure 9-1 shows the schematic for 48-V to 12-V conversion.

SW

BST

PGOOD

VIN

EN/UVLO

GND

RON

FB

LM5013

CIN

2 × 2.2 µF

VIN = 6 V...100 V

CBST

2.2 nF

RRON

100 k

U1

VOUT = 12 V

COUT

22 F

IOUT = 3.5 A

LO

H

RFB1

453 k

RFB2

49.9 k

RA

453 k

CA

3.3 nF

CB

56 pF

DSW

Figure 9-1. Typical Application, VIN(nom) = 48 V, VOUT = 12 V, IOUT(max) = 3.5 A, fSW(nom) = 300 kHz

Note

This and subsequent design examples are provided herein to showcase the LM5013 converter

in several different applications. Depending on the source impedance of the input supply bus, an

electrolytic capacitor can be required at the input to ensure stability, particularly at low input voltage

and high output current operating conditions. See the Power Supply Recommendations section for

more details.

9.2.1 Design Requirements

The target full-load efficiency is 92% based on a nominal input voltage of 48 V and an output voltage of 12 V.

The required input voltage range is 15 V to 100 V. The switching frequency is set by resistor RON at 300 kHz.

The output voltage soft-start time is 3 ms. Refer to LM5013-Q1 EVM user's guide for more detail on component

selection.

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LM5013

SNVSCB3 – OCTOBER 2022

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