Electronic Components Datasheet Search
  English  ▼
ALLDATASHEET.COM

X  

LM2673SD-3.3 Datasheet(PDF) 10 Page - Texas Instruments

Part # LM2673SD-3.3
Description  LM2673 SIMPLE SWITCHER 3A Step-Down Voltage Regulator with Adjustable Current
Download  35 Pages
Scroll/Zoom Zoom In 100%  Zoom Out
Manufacturer  TI [Texas Instruments]
Direct Link  http://www.ti.com
Logo TI - Texas Instruments

LM2673SD-3.3 Datasheet(HTML) 10 Page - Texas Instruments

Back Button LM2673SD-3.3 Datasheet HTML 6Page - Texas Instruments LM2673SD-3.3 Datasheet HTML 7Page - Texas Instruments LM2673SD-3.3 Datasheet HTML 8Page - Texas Instruments LM2673SD-3.3 Datasheet HTML 9Page - Texas Instruments LM2673SD-3.3 Datasheet HTML 10Page - Texas Instruments LM2673SD-3.3 Datasheet HTML 11Page - Texas Instruments LM2673SD-3.3 Datasheet HTML 12Page - Texas Instruments LM2673SD-3.3 Datasheet HTML 13Page - Texas Instruments LM2673SD-3.3 Datasheet HTML 14Page - Texas Instruments Next Button
Zoom Inzoom in Zoom Outzoom out
 10 / 35 page
background image
LM2673
SNVS030N – APRIL 2000 – REVISED APRIL 2013
www.ti.com
The individual components from the various manufacturers called out for use are still just a small sample of the
vast array of components available in the industry. While these components are recommended, they are not
exclusively the only components for use in a design. After a close comparison of component specifications,
equivalent devices from other manufacturers could be substituted for use in an application.
Important considerations for each external component and an explanation of how the nomographs and selection
tables were developed follows.
INDUCTOR
The inductor is the key component in a switching regulator. For efficiency the inductor stores energy during the
switch ON time and then transfers energy to the load while the switch is OFF.
Nomographs are used to select the inductance value required for a given set of operating conditions. The
nomographs assume that the circuit is operating in continuous mode (the current flowing through the inductor
never falls to zero). The magnitude of inductance is selected to maintain a maximum ripple current of 30% of the
maximum load current. If the ripple current exceeds this 30% limit the next larger value is selected.
The inductors offered have been specifically manufactured to provide proper operation under all operating
conditions of input and output voltage and load current. Several part types are offered for a given amount of
inductance. Both surface mount and through-hole devices are available. The inductors from each of the three
manufacturers have unique characteristics.
Renco: ferrite stick core inductors; benefits are typically lowest cost and can withstand ripple and transient peak
currents above the rated value. These inductors have an external magnetic field, which may generate EMI.
Pulse Engineering: powdered iron toroid core inductors; these also can withstand higher than rated currents and,
being toroid inductors, will have low EMI.
Coilcraft: ferrite drum core inductors; these are the smallest physical size inductors and are available only as
surface mount components. These inductors also generate EMI but less than stick inductors.
OUTPUT CAPACITOR
The output capacitor acts to smooth the dc output voltage and also provides energy storage. Selection of an
output capacitor, with an associated equivalent series resistance (ESR), impacts both the amount of output ripple
voltage and stability of the control loop.
The output ripple voltage of the power supply is the product of the capacitor ESR and the inductor ripple current.
The capacitor types recommended in the tables were selected for having low ESR ratings.
In addition, both surface mount tantalum capacitors and through-hole aluminum electrolytic capacitors are offered
as solutions.
Impacting frequency stability of the overall control loop, the output capacitance, in conjunction with the inductor,
creates a double pole inside the feedback loop. In addition the capacitance and the ESR value create a zero.
These frequency response effects together with the internal frequency compensation circuitry of the LM2673
modify the gain and phase shift of the closed loop system.
As a general rule for stable switching regulator circuits it is desired to have the unity gain bandwidth of the circuit
to be limited to no more than one-sixth of the controller switching frequency. With the fixed 260KHz switching
frequency of the LM2673, the output capacitor is selected to provide a unity gain bandwidth of 40KHz maximum.
Each recommended capacitor value has been chosen to achieve this result.
In some cases multiple capacitors are required either to reduce the ESR of the output capacitor, to minimize
output ripple (a ripple voltage of 1% of Vout or less is the assumed performance condition), or to increase the
output capacitance to reduce the closed loop unity gain bandwidth (to less than 40KHz). When parallel
combinations of capacitors are required it has been assumed that each capacitor is the exact same part type.
10
Submit Documentation Feedback
Copyright © 2000–2013, Texas Instruments Incorporated
Product Folder Links: LM2673


Similar Part No. - LM2673SD-3.3

ManufacturerPart #DatasheetDescription
logo
National Semiconductor ...
LM2673SD-3.3 NSC-LM2673SD-3.3 Datasheet
451Kb / 26P
   SIMPLE SWITCHER 3A Step-Down Voltage Regulator with Adjustable Current Limit
LM2673SD-3.3 NSC-LM2673SD-3.3 Datasheet
650Kb / 26P
   SIMPLE SWITCHER짰 3A Step-Down Voltage Regulator with Adjustable Current Limit
logo
Texas Instruments
LM2673SD-3.3/NOPB TI1-LM2673SD-3.3/NOPB Datasheet
2Mb / 37P
[Old version datasheet]   LM2673 SIMPLE SWITCHER짰 3-A Step-Down Voltage Regulator With Adjustable Current Limit
More results

Similar Description - LM2673SD-3.3

ManufacturerPart #DatasheetDescription
logo
National Semiconductor ...
LM2673 NSC-LM2673 Datasheet
451Kb / 26P
   SIMPLE SWITCHER 3A Step-Down Voltage Regulator with Adjustable Current Limit
logo
SeCoS Halbleitertechnol...
S5ELM2576 SECOS-S5ELM2576 Datasheet
967Kb / 8P
   Simple Switcher 3A Step-Down Voltage Regulator
logo
Cystech Electonics Corp...
PL2576-XXXF5 CYSTEKEC-PL2576-XXXF5 Datasheet
223Kb / 10P
   Simple Switcher 3A Step- Down Voltage Regulator
logo
National Semiconductor ...
LM2576 NSC-LM2576 Datasheet
639Kb / 24P
   SIMPLE SWITCHER 3A Step-Down Voltage Regulator
logo
List of Unclassifed Man...
AE2576 ETC-AE2576 Datasheet
569Kb / 11P
   SIMPLE SWITCHER 3A Step-Down Voltage Regulator
Jan.2010 V1.2
logo
Cystech Electonics Corp...
LM2576-XXE5 CYSTEKEC-LM2576-XXE5 Datasheet
340Kb / 12P
   Simple Switcher 3A Step- Down Voltage Regulator
logo
SeCoS Halbleitertechnol...
S5ULM2576 SECOS-S5ULM2576 Datasheet
998Kb / 8P
   Simple Switcher 3A Step-Down Voltage Regulator
logo
GTM CORPORATION
G5ELM2576 GTM-G5ELM2576 Datasheet
358Kb / 7P
   Simple Switcher 3A Step-Down Voltage Regulator
G5ULM2576 GTM-G5ULM2576 Datasheet
356Kb / 7P
   Simple Switcher 3A Step-Down Voltage Regulator
logo
ARTSCHIP ELECTRONICS CO...
LM2576 ARTSCHIP-LM2576 Datasheet
1Mb / 23P
   SIMPLE SWITCHER 3A Step-Down Voltage Regulator
More results


Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35


Datasheet Download

Go To PDF Page


Link URL




Privacy Policy
ALLDATASHEET.COM
Does ALLDATASHEET help your business so far?  [ DONATE ] 

About Alldatasheet   |   Advertisement   |   Datasheet Upload   |   Contact us   |   Privacy Policy   |   Link Exchange   |   Manufacturer List
All Rights Reserved©Alldatasheet.com


Mirror Sites
English : Alldatasheet.com  |   English : Alldatasheet.net  |   Chinese : Alldatasheetcn.com  |   German : Alldatasheetde.com  |   Japanese : Alldatasheet.jp
Russian : Alldatasheetru.com  |   Korean : Alldatasheet.co.kr  |   Spanish : Alldatasheet.es  |   French : Alldatasheet.fr  |   Italian : Alldatasheetit.com
Portuguese : Alldatasheetpt.com  |   Polish : Alldatasheet.pl  |   Vietnamese : Alldatasheet.vn
Indian : Alldatasheet.in  |   Mexican : Alldatasheet.com.mx  |   British : Alldatasheet.co.uk  |   New Zealand : Alldatasheet.co.nz
Family Site : ic2ic.com  |   icmetro.com