GND

FB

VSW

VIN

SHDN

L

22 PH

LM3501-16

VOUT

AGND

A1

CNTRL

C3

B1

C1

C2

B3

A2

A3

<0.3V

>1.1V

VIN

2.7V - 5.5V

Voltage

Control

R2

24:

COUT

1PF

Ceramic

CIN

1PF

Ceramic

LM3501

www.ti.com

SNVS230C – DECEMBER 2003 – REVISED MAY 2013

LM3501 Synchronous Step-up DC/DC Converter for White LED Applications

Check for Samples: LM3501

1

FEATURES

APPLICATIONS

2

•

Synchronous Rectification, High Efficiency

•

LCD Bias Supplies

and no External Schottky Diode required

•

White LED Back-Lighting

•

Uses Small Surface Mount Components

•

Handheld Devices

•

Can Drive 2-5 White LEDs in Series (May

•

Digital Cameras

Function with More Low VF LEDs)

•

Portable Applications

•

2.7V to 7V Input Range

•

True Shutdown Isolation, no LED Leakage

DESCRIPTION

Current

The LM3501 is a fixed-frequency step-up DC/DC

converter that is ideal for driving white LEDs for

•

DC Voltage LED Current Control

display backlighting and other lighting functions. With

•

Input Undervoltage Lockout

fully integrated synchronous switching (no external

•

Internal Output Over-Voltage Protection (OVP)

schottky diode required) and a low feedback voltage

Circuitry, with no External Zener Diode

(515 mV), power efficiency of the LM3501 circuit has

Required LM3501-16: 15.5V OVP; LM3501-21:

been optimized for lighting applications in wireless

phones and other portable products (single cell Li-Ion

20.5V OVP.

or 3-cell NiMH battery supplies). The LM3501

•

Requires Only a Small 16V (LM3501-16) or 25V

operates with a fixed 1 MHz switching frequency.

(LM3501-21) Ceramic Capacitor at the Input

When used with ceramic input and output capacitors,

and Output

the LM3501 provides a small, low-noise, low-cost

•

Thermal Shutdown

solution.

•

0.1µA shutdown Current

•

Small 8-Bump Thin DSBGA Package

Typical Application Circuit

Figure 1. Typical 3 LED Application

1

Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of

Texas Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet.

2

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PRODUCTION DATA information is current as of publication date.

Copyright © 2003–2013, Texas Instruments Incorporated

Products conform to specifications per the terms of the Texas

Instruments standard warranty. Production processing does not

necessarily include testing of all parameters.