전자부품 데이터시트 검색엔진
  Korean  ▼
ALLDATASHEET.CO.KR

X  

LM3481QMM 데이터시트(PDF) 8 Page - Texas Instruments

부품명 LM3481QMM
상세설명  LM3481/LM3481Q High Efficiency Low-Side N-Channel Controller for Switching
Download  30 Pages
Scroll/Zoom Zoom In 100%  Zoom Out
제조업체  TI [Texas Instruments]
홈페이지  http://www.ti.com
Logo TI - Texas Instruments

LM3481QMM 데이터시트(HTML) 8 Page - Texas Instruments

Back Button LM3481QMM Datasheet HTML 4Page - Texas Instruments LM3481QMM Datasheet HTML 5Page - Texas Instruments LM3481QMM Datasheet HTML 6Page - Texas Instruments LM3481QMM Datasheet HTML 7Page - Texas Instruments LM3481QMM Datasheet HTML 8Page - Texas Instruments LM3481QMM Datasheet HTML 9Page - Texas Instruments LM3481QMM Datasheet HTML 10Page - Texas Instruments LM3481QMM Datasheet HTML 11Page - Texas Instruments LM3481QMM Datasheet HTML 12Page - Texas Instruments Next Button
Zoom Inzoom in Zoom Outzoom out
 8 / 30 page
background image
FB
FA/SYNC/SD
COMP
ISEN
AGND
PGND
DR
VIN
Shutdown Detect
SYNC/Fixed
Frequency detect
Soft-start
+
EA
+
-
+
Slope
Compensation
Thermal
Shutdown
Set/Blankout
Switch
Logic
Switch
Driver
1.275V
Reference
Oscillator
+
220 mV
Level Shifter
6
+
One Shot
Bias
Voltages
6V
Overvoltage
Comparator
Short-circuit
Comparator
Ramp
Adjust
V-I
Converter
I-V
Converter
PWM
Comparator
R
S
Q
VCC
UVLO
UVLO
40 é
A
Vfb + Vovp
-
-
-
-
LM3481
SNVS346E – NOVEMBER 2007 – REVISED APRIL 2012
www.ti.com
FUNCTIONAL BLOCK DIAGRAM
FUNCTIONAL DESCRIPTION
The LM3481 uses a fixed frequency, Pulse Width Modulated (PWM), current mode control architecture. In a
typical application circuit, the peak current through the external MOSFET is sensed through an external sense
resistor. The voltage across this resistor is fed into the ISEN pin. This voltage is then level shifted and fed into the
positive input of the PWM comparator. The output voltage is also sensed through an external feedback resistor
divider network and fed into the error amplifier (EA) negative input (feedback pin, FB). The output of the error
amplifier (COMP pin) is added to the slope compensation ramp and fed into the negative input of the PWM
comparator.
At the start of any switching cycle, the oscillator sets the RS latch using the SET/Blank-out and switch logic
blocks. This forces a high signal on the DR pin (gate of the external MOSFET) and the external MOSFET turns
on. When the voltage on the positive input of the PWM comparator exceeds the negative input, the RS latch is
reset and the external MOSFET turns off.
The voltage sensed across the sense resistor generally contains spurious noise spikes, as shown in Figure 18.
These spikes can force the PWM comparator to reset the RS latch prematurely. To prevent these spikes from
resetting the latch, a blank-out circuit inside the IC prevents the PWM comparator from resetting the latch for a
short duration after the latch is set. This duration, called the blank-out time, is typically 250 ns and is specified as
tmin (on) in the electrical characteristics section.
Under extremely light load or no-load conditions, the energy delivered to the output capacitor when the external
MOSFET is on during the blank-out time is more than what is delivered to the load. An over-voltage comparator
inside the LM3481 prevents the output voltage from rising under these conditions by sensing the feedback (FB
pin) voltage and resetting the RS latch. The latch remains in a reset state until the output decays to the nominal
value. Thus the operating frequency decreases at light loads, resulting in excellent efficiency.
8
Submit Documentation Feedback
Copyright © 2007–2012, Texas Instruments Incorporated
Product Folder Links: LM3481


유사한 부품 번호 - LM3481QMM

제조업체부품명데이터시트상세설명
logo
Texas Instruments
LM3481QMM/NOPB TI1-LM3481QMM/NOPB Datasheet
1Mb / 30P
[Old version datasheet]   LM3481/LM3481Q High Efficiency Low-Side N-Channel Controller for Switching Regulators
LM3481QMMX/NOPB TI1-LM3481QMMX/NOPB Datasheet
1Mb / 30P
[Old version datasheet]   LM3481/LM3481Q High Efficiency Low-Side N-Channel Controller for Switching Regulators
More results

유사한 설명 - LM3481QMM

제조업체부품명데이터시트상세설명
logo
Texas Instruments
LM3481MM TI1-LM3481MM Datasheet
1Mb / 30P
[Old version datasheet]   LM3481/LM3481Q High Efficiency Low-Side N-Channel Controller for Switching Regulators
logo
National Semiconductor ...
LM3488 NSC-LM3488_05 Datasheet
1,001Kb / 24P
   High Efficiency Low-Side N-Channel Controller for Switching Regulators
LM3478 NSC-LM3478 Datasheet
624Kb / 21P
   High Efficiency Low-Side N-Channel Controller for Switching Regulator
logo
Texas Instruments
LM3488MMX TI-LM3488MMX Datasheet
1Mb / 33P
[Old version datasheet]   High Efficiency Low-Side N-Channel Controller for Switching Regulators
LM3488 TI1-LM3488 Datasheet
1Mb / 37P
[Old version datasheet]   High-Efficiency, Low-Side, N-Channel Controller for Switching Regulators
LM3478 TI1-LM3478 Datasheet
1Mb / 32P
[Old version datasheet]   High-Efficiency Low-Side N-Channel Controller for Switching Regulator
LM3478MA TI-LM3478MA_15 Datasheet
670Kb / 26P
[Old version datasheet]   High-Efficiency Low-Side N-Channel Controller for Switching Regulator
logo
National Semiconductor ...
LM3488 NSC-LM3488 Datasheet
626Kb / 24P
   High Efficiency Low-Side N-Channel Controller for Switching Regulators
LM3481 NSC-LM3481 Datasheet
445Kb / 22P
   High Efficiency Low-Side N-Channel Controller for Switching Regulators
logo
Texas Instruments
LM3488MM TI-LM3488MM Datasheet
1Mb / 33P
[Old version datasheet]   High Efficiency Low-Side N-Channel Controller for Switching Regulators
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


데이터시트 다운로드

Go To PDF Page


링크 URL




개인정보취급방침
ALLDATASHEET.CO.KR
ALLDATASHEET 가 귀하에 도움이 되셨나요?  [ DONATE ] 

Alldatasheet는?   |   광고문의   |   운영자에게 연락하기   |   개인정보취급방침   |   링크교환   |   제조사별 검색
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