GND

FB

PGND

VG

DR

VIN

LM3017

COMP

VCC

EN/MODE

ISEN

AGND

CIN1

CBYP

CVCC

CCOMP2

CCOMP

RCOMP

L1

Q2

Q1

RFBT

RFBB

CO2

CO1

CO3

RSEN

RS

D1

U1

EN/MODE

GND

VIN = 8V to 12V

VOUT = 15V@1A

Copyright © 2016, Texas Instruments Incorporated

14

LM3017

SNOSC66D – MARCH 2012 – REVISED SEPTEMBER 2016

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Product Folder Links: LM3017

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Copyright © 2012–2016, 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 LM3017 may be operated in either continuous or discontinuous conduction mode. The following descriptions

assume continuous conduction operation (CCM). This mode of operation has higher efficiency and lower EMI

characteristics than the discontinuous mode.

8.2 Typical Application

Figure 16. 1-A High Efficiency Step-Up (Boost) Converter

8.2.1 Design Requirements

To properly size the components for the application, the designer requires the following parameters: Input

voltage range, output voltage, output current, and switching frequency. These four main parameters affect the

choices of component available to achieve a proper system behavior.

Table 2 lists the design parameters for this application example.

Table 2. Design Parameters

PARAMETER

VALUE

Input voltage, VIN

8 V to 12 V

Output voltage, VOUT

15 V

Output current, IOUT

1 A

Switching frequency, fS

600 kHz

8.2.2 Detailed Design Procedure

The most common topology for the LM3017 is the boost or step-up topology. The boost converter converts a low

input voltage into a higher output voltage. The basic configuration for a boost regulator is shown in Figure 17. In

continuous conduction mode (when the inductor current never reaches zero at steady state), the boost regulator

operates in two cycles. In the first cycle of operation, MOSFET Q is turned on and energy is stored in the

inductor. During this cycle, diode D1 is reverse biased and load current is supplied by the output capacitor,

COUT.