1. FAN5345: Asynchronous Series. Boost LED Driver with
FAN5345: Asynchronous Series Boost LED Driver with Single-wire Digital Interface
Product Presentation

2. Overview
Larger displays are an emerging trend in mobile handsets today’s especially in smartphones.
Typical size of LCD displays tend to be 3.7” to 4.3” in size.
Ideal solution to backlight LCD displays of this size is with LED drivers that drive white LEDs in series.
Simplifies layout and provides equal brightness for all LEDs.
Efficiency becomes an extremely important parameter with larger displays as more LEDs are needed to backlight it.
The more LEDs required means greater current consumption, therefore an efficient LED driver solution is highly desirable.

3. Introduction
FAN5345 is an asynchronous series boost LED driver that can drive up to 8 white LEDs in series
Compact and cost effective solution that provides superior performance
Up to 85% efficiency
32 linear dimming steps for greater brightness resolution
Small form factor SSOT6 package format
By driving the LEDs in series, it ensures that all LEDs will have equal brightness

4. FAN5345 Asynchronous Series Boost LED Driver w/ Digital Interface
Features
Asynchronous Serial LED Driver
Up to 85% efficiency
Supports up to 8 LEDs
1.2MHz switching frequency
Single-wire digital control interface
Program up to 32 different LED brightness levels
VIN = 2.5V to 5.5V
Over-Voltage Protection
Short Circuit Detection
Thermal Shutdown Protection
Pkg: 6-lead SSOT23
Applications
Mobile Handsets
MP3 Players
Mobile Internet Devices
Rugged Handheld PCs
Portable Medical Equipment
Company Confidential

5. Digital Dimming
32 linear dimming steps to provide greater brightness resolution control
Finer resolution at lower current levels to provide smoother dimming
Simple single-wire digital interface to set the appropriate brightness level by applying digital pulses

6. FAN5345 Efficiency
6 LEDs in Series
8 LEDs in Series

7. FAN5345 Features & Benefits
High Efficiency
Up to 85% peak efficiency to minimize power consumption in portable products
Serial Driver
Drives LEDs in series to enable equal level of brightness for all LEDs
Supports up to 8 LEDs to display 4” LCD displays
No need to worry about current matching between channels
Single-Wire Digital Interface
Simple single-wire digital interface to enable linear dimming
32 linear dimming steps to provide greater brightness resolution
1.2MHz Switching Frequency
Enables use of smaller size capacitors and inductors (10µH)
Lower inductor and capacitor costs
Small Form Factor
Saves PCB space in portable products
Company Confidential

8. Pricing & Availability
Fairchild Part Number
Package
Unit 1ku
Availability
FAN5345S20X
SSOT6
$0.59
Now
FAN5345S30X
$0.65

9. Technical Materials FAN5345 Datasheet
FAN5345 Product Overview
Evaluation Boards
Request via Sales Center
Samples

10. Marketing & Apps Contacts
Marketing Contact
Wayne Seto
Applications Support
Hunter Chou

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