LM2705 Datasheet, PDF (1/20 Pages) National Semiconductor (TI) – Micropower Step-up DC/DC Converter with 150mA Peak Current Limit

LM2705
www.ti.com
SNVS191E – NOVEMBER 2002 – REVISED MAY 2013
LM2705 Micropower Step-up DC/DC Converter with 150mA Peak Current Limit
Check for Samples: LM2705
FEATURES
1
•2 150mA, 0.7Ω, internal switch
• Uses small surface mount components
• Adjustable output voltage up to 20V
• 2.2V to 7V input range
• Input undervoltage lockout
• 0.01µA shutdown current
• Small 5-Lead SOT-23 package
APPLICATIONS
• LCD Bias Supplies
• White LED Back-Lighting
• Handheld Devices
• Digital Cameras
• Portable Applications
DESCRIPTION
The LM2705 is a micropower step-up DC/DC in a
small 5-lead SOT-23 package. A current limited, fixed
off-time control scheme conserves operating current
resulting in high efficiency over a wide range of load
conditions. The 21V switch allows for output voltages
as high as 20V. The low 400ns off-time permits the
use of tiny, low profile inductors and capacitors to
minimize footprint and cost in space-conscious
portable applications. The LM2705 is ideal for LCD
panels requiring low current and high efficiency as
well as white LED applications for cellular phone
back-lighting. The LM2705 can drive up to 3 white
LEDs from a single Li-Ion battery. The low peak
inductor current of the LM2705 makes it ideal for USB
applications.
Typical Application Circuit
V_IN = Li-Ion
L
68 PH
D
20V
6 mA
C_IN
4.7 PF
5
1
V_IN
SW
4
LM2705
3
SHDN
FB
GND
2
R1
510k
R2
33k
C_OUT
1 PF
C_IN: Taiyo Yuden Ceramic
C_OUT: Taiyo Yuden Ceramic
L: Coilcraft DT1608C-683
D: ON Semiconductor MBRM130LT3
Figure 1. Typical 20V 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.
All trademarks are the property of their respective owners.
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 © 2002–2013, Texas Instruments Incorporated