LM2703MF-ADJ/NOPB National Semiconductor, LM2703MF-ADJ/NOPB Datasheet

IC CONV DC/DC MICPWR SOT23-5

LM2703MF-ADJ/NOPB

Manufacturer Part Number
LM2703MF-ADJ/NOPB
Description
IC CONV DC/DC MICPWR SOT23-5
Manufacturer
National Semiconductor
Datasheet

Specifications of LM2703MF-ADJ/NOPB

Constant Current
*
Constant Voltage
*
Topology
*
Number Of Outputs
*
Internal Driver
*
Type - Primary
*
Type - Secondary
*
Frequency
*
Voltage - Supply
*
Voltage - Output
*
Mounting Type
Surface Mount
Package / Case
SOT-23-5, SC-74A, SOT-25
Operating Temperature
*
Current - Output / Channel
*
Internal Switch(s)
*
Efficiency
*
Primary Input Voltage
7V
No. Of Outputs
1
Output Voltage
21V
Output Current
350mA
No. Of Pins
5
Operating Temperature Range
-40°C To +125°C
Msl
MSL 1 - Unlimited
Filter Terminals
SMD
Rohs Compliant
Yes
For Use With
LM2703EV - BOARD EVALUATION LM2703
Lead Free Status / RoHS Status
Lead free / RoHS Compliant
Other names
LM2703MF-ADJ
LM2703MF-ADJTR
© 2006 National Semiconductor Corporation
LM2703
Micropower Step-Up DC/DC Converter with 350mA Peak
Current Limit
General Description
The LM2703 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 22V
switch allows for output voltages as high as 21V. 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 LM2703 is ideal for
LCD panels requiring low current and high efficiency as well
as white LED applications for cellular phone back-lighting.
The LM2703 can drive up to 4 white LEDs from a single
Li-Ion battery.
Typical Application Circuit
DS200306
FIGURE 1. Typical 20V Application
Features
n 350mA, 0.7Ω, internal switch
n Uses small surface mount components
n Adjustable output voltage up to 21V
n 2.2V to 7V input range
n Input undervoltage lockout
n 0.01µA shutdown current
n Small 5-Lead SOT-23 package
Applications
n LCD Bias Supplies
n White LED Back-Lighting
n Handheld Devices
n Digital Cameras
n Portable Applications
20030601
www.national.com
June 2006

Related parts for LM2703MF-ADJ/NOPB

LM2703MF-ADJ/NOPB Summary of contents

Page 1

... LED applications for cellular phone back-lighting. The LM2703 can drive white LEDs from a single Li-Ion battery. Typical Application Circuit © 2006 National Semiconductor Corporation Features n 350mA, 0.7Ω, internal switch n Uses small surface mount components n Adjustable output voltage up to 21V n 2 ...

Page 2

... Connection Diagram Ordering Information Order Number Package Type LM2703MF-ADJ SOT23-5 LM2703MFX-ADJ SOT23-5 Pin Descriptions/Functions Pin Name GND SHDN SW(Pin 1): Switch Pin. This is the drain of the internal NMOS power switch. Minimize the metal trace area con- nected to this pin to minimize EMI. GND(Pin 2): Ground Pin. Tie directly to ground plane. ...

Page 3

... Absolute Maximum Ratings If Military/Aerospace specified devices are required, please contact the National Semiconductor Sales Office/ Distributors for availability and specifications Voltage FB Voltage SHDN Voltage Maximum Junction Temp (Note 2) Lead Temperature (Soldering 10 sec.) Vapor Phase (60 sec.) Electrical Characteristics Specifications in standard type face are for T Range (T = − ...

Page 4

Typical Performance Characteristics Enable Current vs V (Part Switching) Efficiency vs Load Current www.national.com IN 20030605 20030610 4 Disable Current (Part Not Switching) 20030606 Efficiency vs Load Current 20030611 ...

Page 5

Typical Performance Characteristics Efficiency vs Load Current Switch Current Limit vs V (Continued) 20030612 IN 20030614 5 SHDN Threshold 20030613 Switch DSON IN 20030615 www.national.com ...

Page 6

Typical Performance Characteristics FB Trip Point and FB Pin Current vs Temperature Step Response V = 20V 2.5V OUT IN 1) Load, 1mA to 10mA to 1mA 200mV/div, AC OUT 200mA/div, ...

Page 7

Operation V = 20V 2.5V OUT 20V/div Inductor Current, 200mA/div 200mV/div, AC OUT T = 4µs/div FIGURE 2. LM2703 Block Diagram FIGURE 3. Typical Switching Waveform 7 ...

Page 8

Operation (Continued) The LM2703 features a constant off-time control scheme. Operation can be best understood by referring to Figure 2 and Figure 3. Transistors Q1 and Q2 and resistors R3 and R4 of Figure 2 form a bandgap reference used ...

Page 9

Application Information (Continued) FIGURE 4. White LED Application FIGURE 5. Li-Ion 5V Application FIGURE 6. Li-Ion 12V Application 9 20030609 20030619 20030620 www.national.com ...

Page 10

Application Information www.national.com (Continued) FIGURE 12V Application 10 20030621 ...

Page 11

... BANNED SUBSTANCE COMPLIANCE National Semiconductor follows the provisions of the Product Stewardship Guide for Customers (CSP-9-111C2) and Banned Substances and Materials of Interest Specification (CSP-9-111S2) for regulatory environmental compliance. Details may be found at: www.national.com/quality/green. ...

Page 12

Tel: 81-3-5639-7560 ...

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