IN

HWEN

LM3648

SDA

SCL

SW

OUT

LED

STROBE

TORCH/

TEMP

GND

TX

10 PF

10 PF

C2

L1

C1

PP/PC

VIN

2.5V t 5.5V

1 PH

22

LM3648, LM3648TT

SNVSA68D – OCTOBER 2014 – REVISED NOVEMBER 2016

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Product Folder Links: LM3648 LM3648TT

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Copyright © 2014–2016, Texas Instruments Incorporated

8 Applications 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 LM3648 can drive a flash LED at currents up to 1.5 A. The 2-MHz or 4-MHz DC-DC boost regulator allows

for the use of small value discrete external components.

8.2 Typical Application

Figure 31. LM3648 Typical Application

8.2.1 Design Requirements

Example requirements based on default register values:

Table 1. Design Parameters

DESIGN PARAMETER

EXAMPLE VALUE

Input Voltage Range

2.5 V to 5.5 V

Brightness Control

I2C Register

LED Configuration

1 Flash LED

Boost Switching Frequency

2 MHz (4 MHz selectable)

Flash Brightness

1.5-A Max Current