FB

GND

SW

C

B

SHDN

LM2840/1/2-ADJL

3.3V OUT

4.5V to 42V IN

D1

MA2YD26

R1

3.4k

R2

1.02k

CBOOT

VIN

CIN

2.2 PF

0.1 PF

L1

15 PH

COUT

10 PF

Copyright © 2016, Texas Instruments Incorporated

11

LM2840-Q1, LM2841-Q1, LM2842-Q1

www.ti.com

SNVSBE5 – APRIL 2019

Product Folder Links: LM2840-Q1 LM2841-Q1 LM2842-Q1

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Copyright © 2019, Texas Instruments Incorporated

8 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. Customers should

validate and test their design implementation to confirm system functionality.

8.1 Application Information

The LM284x-Q1 are step-down DC/DC regulators. They are typically used to convert a higher DC voltage to a

lower DC voltage with a maximum output current of 100 mA, 300 mA, or 600 mA. The following design

procedure can be used to select components for the LM284x-Q1. Alternately, the WEBENCH® software may be

used to generate complete designs. When generating a design, the WEBENCH software uses iterative design

procedure and accesses comprehensive databases of components. See ti.com and Detailed Design Procedure

for more details

8.2 Typical Applications

Figure 9. Application Circuit With 3.3-V Output Voltage at 100 mA

8.2.1 Design Requirements

Table 1 lists the design parameters for this example.

Table 1. Design Parameters

DESIGN PARAMETER

EXAMPLE VALUE

Input voltage

4.5 V to 42 V

Output voltage

3.3 V

Output current

0.1 A

8.2.2 Detailed Design Procedure

8.2.2.1 Custom Design With WEBENCH® Tools

Click here to create a custom design using the LM2840 device with the WEBENCH® Power Designer.

1. Start by entering the input voltage (VIN), output voltage (VOUT), and output current (IOUT) requirements.

2. Optimize the design for key parameters such as efficiency, footprint, and cost using the optimizer dial.

3. Compare the generated design with other possible solutions from Texas Instruments.

The WEBENCH Power Designer provides a customized schematic along with a list of materials with real-time

pricing and component availability.

In most cases, these actions are available: