LM3502_15 Datasheet, PDF (1/28 Pages) Texas Instruments – Step-Up Converter for White LED Applications

LM3502
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SNVS339B – SEPTEMBER 2005 – REVISED MAY 2013
LM3502 Step-Up Converter for White LED Applications
Check for Samples: LM3502
FEATURES
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•2 Drive up to 4, 6, 8 or 10 White LEDs for Dual
Display Backlighting
• >80% Efficiency
• Output Voltage Options: 16V , 25V , 35V, and
44V
• Input Under-Voltage Protection
• Internal Soft Start Eliminating Inrush Current
• 1 MHz Constant Switching Frequency
• Wide Input Voltage: 2.5V to 5.5V
• Small External Components
• Low Profile Packages: <1 mm Height
– 10 Bump DSBGA
– 16 Pin WQFN
APPLICATIONS
• Dual Display Backlighting in Portable Devices
• Cellular Phones and PDAs
DESCRIPTION
The LM3502 is a white LED driver for lighting
applications. For dual display or large single white
LED string backlighting applications, the LM3502
provides a complete solution. The LM3502 contains
two internal white LED current bypass FET(Field
Effect Transistor) switches that are ideal for
controlling dual display applications. The white LED
current can be adjusted with a PWM signal directly
from a microcontroller without the need of an RC filter
network.
Typical Application
L
22 PH
D
V_SUPPLY
C_IN
4.7 PF
Sw
V_IN
V_OUT1
Cntrl
V_OUT2
LM3502-44
En1
Fb
En2
AGND PGND
Logic
Voltage
Signal
Inputs
MAIN:
2 to 5
LEDs
C_OUT
1 PF
SUB:
2 to 5
LEDs
R1
Figure 1. Blacklight Configuration with 10 White LEDs
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Texas Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet.
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2
PRODUCTION DATA information is current as of publication date.
Products conform to specifications per the terms of the Texas
Instruments standard warranty. Production processing does not
necessarily include testing of all parameters.
Copyright © 2005–2013, Texas Instruments Incorporated