Electronic Components Datasheet Search
  English  ▼
ALLDATASHEET.NET

X  

LM25574 Datasheet(PDF) 11 Page - Texas Instruments

Click here to check the latest version.
Part # LM25574
Description  SIMPLE SWITCHER짰 42V, 0.5A Step-Down Switching Regulator
Download  30 Pages
Scroll/Zoom Zoom In 100%  Zoom Out
Manufacturer  TI1 [Texas Instruments]
Direct Link  http://www.ti.com
Logo TI1 - Texas Instruments

LM25574 Datasheet(HTML) 11 Page - Texas Instruments

Back Button LM25574 Datasheet HTML 7Page - Texas Instruments LM25574 Datasheet HTML 8Page - Texas Instruments LM25574 Datasheet HTML 9Page - Texas Instruments LM25574 Datasheet HTML 10Page - Texas Instruments LM25574 Datasheet HTML 11Page - Texas Instruments LM25574 Datasheet HTML 12Page - Texas Instruments LM25574 Datasheet HTML 13Page - Texas Instruments LM25574 Datasheet HTML 14Page - Texas Instruments LM25574 Datasheet HTML 15Page - Texas Instruments Next Button
Zoom Inzoom in Zoom Outzoom out
 11 / 30 page
background image
SYNC
10k
S
R
Q
Q
DEADTIME
ONE-SHOT
5V
2.5V
I = f(RT)
LM25574
www.ti.com
SNVS483F – JANUARY 2007 – REVISED FEBRUARY 2009
Figure 5. Simplified Oscillator Block Diagram and SYNC I/O Circuit
Error Amplifier and PWM Comparator
The internal high gain error amplifier generates an error signal proportional to the difference between the
regulated output voltage and an internal precision reference (1.225V). The output of the error amplifier is
connected to the COMP pin allowing the user to provide loop compensation components, generally a type II
network, as illustrated in Typical Application Circuit and Block Diagram. This network creates a pole at DC, a
zero and a noise reducing high frequency pole. The PWM comparator compares the emulated current sense
signal from the RAMP generator to the error amplifier output voltage at the COMP pin.
RAMP Generator
The ramp signal used in the pulse width modulator for current mode control is typically derived directly from the
buck switch current. This switch current corresponds to the positive slope portion of the output inductor current.
Using this signal for the PWM ramp simplifies the control loop transfer function to a single pole response and
provides inherent input voltage feed-forward compensation. The disadvantage of using the buck switch current
signal for PWM control is the large leading edge spike due to circuit parasitics that must be filtered or blanked.
Also, the current measurement may introduce significant propagation delays. The filtering, blanking time and
propagation delay limit the minimum achievable pulsewidth. In applications where the input voltage may be
relatively large in comparison to the output voltage, controlling small pulsewidths and duty cycles is necessary for
regulation. The LM25574 utilizes a unique ramp generator, which does not actually measure the buck switch
current but rather reconstructs the signal. Reconstructing or emulating the inductor current provides a ramp
signal to the PWM comparator that is free of leading edge spikes and measurement or filtering delays. The
current reconstruction is comprised of two elements; a sample & hold DC level and an emulated current ramp.
Copyright © 2007–2009, Texas Instruments Incorporated
Submit Documentation Feedback
11
Product Folder Links: LM25574


Similar Part No. - LM25574

ManufacturerPart #DatasheetDescription
logo
National Semiconductor ...
LM25574 NSC-LM25574 Datasheet
414Kb / 22P
   SIMPLE SWITCHER짰 42V, 0.5A Step-Down Switching Regulator
logo
Texas Instruments
LM25574 TI-LM25574 Datasheet
886Kb / 29P
[Old version datasheet]   LM25574/LM25574-Q1 SIMPLE SWITCHER 42V, 0.5A Step-Down Switching Regulator
LM25574 TI-LM25574 Datasheet
886Kb / 29P
[Old version datasheet]   LM25574/LM25574-Q1 SIMPLE SWITCHER 42V, 0.5A Step-Down Switching Regulator
LM25574 TI1-LM25574 Datasheet
973Kb / 30P
[Old version datasheet]   SIMPLE SWITCHER 42V, 0.5A Step-Down Switching Regulator
LM25574 TI1-LM25574 Datasheet
970Kb / 30P
[Old version datasheet]   SIMPLE SWITCHER 42V, 0.5A Step-Down Switching Regulator
More results

Similar Description - LM25574

ManufacturerPart #DatasheetDescription
logo
National Semiconductor ...
LM25574_0703 NSC-LM25574_0703 Datasheet
414Kb / 22P
   SIMPLE SWITCHER짰 42V, 0.5A Step-Down Switching Regulator
logo
Texas Instruments
LM25575 TI1-LM25575_14 Datasheet
989Kb / 29P
[Old version datasheet]   SIMPLE SWITCHER짰 42V, 1.5A Step-Down Switching Regulator
logo
National Semiconductor ...
LM25576_0703 NSC-LM25576_0703 Datasheet
434Kb / 24P
   SIMPLE SWITCHER짰 42V, 3A Step-Down Switching Regulator
logo
Texas Instruments
LM5574 TI1-LM5574_14 Datasheet
911Kb / 28P
[Old version datasheet]   SIMPLE SWITCHER짰 75V, 0.5A Step-Down Switching Regulator
LM25574 TI1-LM25574_16 Datasheet
973Kb / 30P
[Old version datasheet]   SIMPLE SWITCHER 42V, 0.5A Step-Down Switching Regulator
LM25574 TI1-LM25574_17 Datasheet
970Kb / 30P
[Old version datasheet]   SIMPLE SWITCHER 42V, 0.5A Step-Down Switching Regulator
logo
National Semiconductor ...
LM25007 NSC-LM25007_08 Datasheet
282Kb / 12P
   42V, 0.5A Step-Down Switching Regulator
LM25007 NSC-LM25007 Datasheet
617Kb / 12P
   42V, 0.5A Step-Down Switching Regulator
logo
Texas Instruments
LM25007 TI1-LM25007_14 Datasheet
933Kb / 17P
[Old version datasheet]   42V, 0.5A Step-Down Switching Regulator
LM25007 TI-LM25007_15 Datasheet
956Kb / 20P
[Old version datasheet]   LM25007 42V, 0.5A Step-Down Switching 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


Datasheet Download

Go To PDF Page


Link URL




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

About Alldatasheet   |   Advertisement   |   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