전자부품 데이터시트 검색엔진
  Korean  ▼
ALLDATASHEET.CO.KR

X  

LM2655 데이터시트(PDF) 11 Page - Texas Instruments

Click here to check the latest version.
부품명 LM2655
상세설명  2.5A High Efficiency Synchronous Switching Regulator
Download  18 Pages
Scroll/Zoom Zoom In 100%  Zoom Out
제조업체  TI [Texas Instruments]
홈페이지  http://www.ti.com
Logo TI - Texas Instruments

LM2655 데이터시트(HTML) 11 Page - Texas Instruments

Back Button LM2655 Datasheet HTML 7Page - Texas Instruments LM2655 Datasheet HTML 8Page - Texas Instruments LM2655 Datasheet HTML 9Page - Texas Instruments LM2655 Datasheet HTML 10Page - Texas Instruments LM2655 Datasheet HTML 11Page - Texas Instruments LM2655 Datasheet HTML 12Page - Texas Instruments LM2655 Datasheet HTML 13Page - Texas Instruments LM2655 Datasheet HTML 14Page - Texas Instruments LM2655 Datasheet HTML 15Page - Texas Instruments Next Button
Zoom Inzoom in Zoom Outzoom out
 11 / 18 page
background image
Design Procedure (Continued)
ment. A reasonable value is setting the ripple current to be
30% of the DC output current. Since the ripple current in-
creases with the input voltage, the maximum input voltage is
always used to determine the inductance. The DC resistance
of the inductor is a key parameter for the efficiency. Lower
DC resistance is available with a bigger winding area. A good
tradeoff between the efficiency and the core size is letting the
inductor copper loss equal 2% of the output power.
OUTPUT CAPACITOR
The selection of C
OUT is primarily determined by the maxi-
mum allowable output voltage ripple. The output ripple in the
constant frequency, PWM mode is approximated by:
The ESR term usually plays the dominant role in determining
the voltage ripple. A low ESR aluminum electrolytic or tanta-
lum capacitor (such as Nichicon PL series, Sanyo OS-CON,
Sprague 593D, 594D, AVX TPS, and CDE polymer alumi-
num) is recommended. An electrolytic capacitor is not rec-
ommended for temperatures below −25˚C since its ESR
rises dramatically at cold temperature. A tantalum capacitor
has a much better ESR specification at cold temperature and
is preferred for low temperature applications.
The output voltage ripple in constant frequency mode has to
be less than the sleep mode voltage hysteresis to avoid
entering the sleep mode at full load:
V
RIPPLE < 20mV * VOUT /VFB
TABLE 1. MOSFET Manufacturers
Manufacturer
Model Number
Package Type
www Address
Phone
Fax
Fairchild
Semiconductor
FDC653N
SuperSOT-6
www.fairchildsemi.com 888-522-5372
207-761-6020
General
Semiconductor
GF4420
SO-8
www.gensemi.com
631-847-3000
631-847-3236
International
Rectifier
IRF7807
SO-8
www.irf.com
310-322-3331
310-322-3332
Vishay Siliconix
Si4812DY
SO-8
www.vishay.com
800-554-5565
408-567-8995
Si4874DY
SO-8
Zetex
ZXM64N03X
SO-8
www.zetex.com
(44) 161-622-4422
(44) 161-622-4420
LOW-SIDE MOSFET SELECTION
When operating in synchronous mode, special attention
should be given to the selection of the low-side MOSFET.
Besides choosing a MOSFET with minimal size and on
resistance, it is critical that the MOSFET meet certain rise
and fall time specifications. A 30ns deadtime between the
low-side and high-side MOSFET switching transitions is pro-
grammed into the LM2655, as shown in Figure 1. The pre-
vent shoot-through current, the low-side MOSFET must turn
off before the high-side MOSFET turns on. Hence, the low-
side MOSFET has 30ns to turn off from the time the low-side
driver goes low. The fall time of the low-side MOSFET is
governed by the equation:
I
C =CIN*dVC/dt.
where I
C is the LDR sink current capability, CIN is the equiva-
lent capacitance seen at the LDR pin, and V
C is the gate-to-
source voltage of the MOSFET. I
C is limited by the low-side
driver of the LM2655, but C
IN is fixed by the MOSFET.
Therefore, it is important that the chosen MOSFET has a
suitable C
IN so that the LM2655 will be able to turn it off
10128421
FIGURE 1. Low-side/high-side driver timing diagram.
www.national.com
10


유사한 부품 번호 - LM2655

제조업체부품명데이터시트상세설명
logo
National Semiconductor ...
LM2655 NSC-LM2655 Datasheet
377Kb / 16P
   2.5A High Efficiency Synchronous Switching Regulator
LM2655 NSC-LM2655 Datasheet
769Kb / 16P
   2.5A High Efficiency Synchronous Switching Regulator
LM2655MTC-3.3 NSC-LM2655MTC-3.3 Datasheet
769Kb / 16P
   2.5A High Efficiency Synchronous Switching Regulator
LM2655MTC-ADJ NSC-LM2655MTC-ADJ Datasheet
377Kb / 16P
   2.5A High Efficiency Synchronous Switching Regulator
LM2655MTC-ADJ NSC-LM2655MTC-ADJ Datasheet
769Kb / 16P
   2.5A High Efficiency Synchronous Switching Regulator
More results

유사한 설명 - LM2655

제조업체부품명데이터시트상세설명
logo
National Semiconductor ...
LM2655 NSC-LM2655 Datasheet
377Kb / 16P
   2.5A High Efficiency Synchronous Switching Regulator
LM2655 NSC-LM2655_05 Datasheet
769Kb / 16P
   2.5A High Efficiency Synchronous Switching Regulator
logo
Fitipower Integrated Te...
FP6375 FITIPOWER-FP6375 Datasheet
1Mb / 13P
   High Efficiency 1MHz 2.5A Synchronous Step Down Regulator
logo
Texas Instruments
LM2651 TI1-LM2651_14 Datasheet
966Kb / 20P
[Old version datasheet]   1.5A High Efficiency Synchronous Switching Regulator
logo
National Semiconductor ...
LM2653 NSC-LM2653 Datasheet
243Kb / 13P
   1.5A High Efficiency Synchronous Switching Regulator
LM2653 NSC-LM2653_05 Datasheet
663Kb / 12P
   1.5A High Efficiency Synchronous Switching Regulator
LM2651 NSC-LM2651 Datasheet
222Kb / 10P
   1.5A High Efficiency Synchronous Switching Regulator
LM2651 NSC-LM2651_05 Datasheet
630Kb / 11P
   1.5A High Efficiency Synchronous Switching Regulator
logo
Monolithic Power System...
MP2120 MPS-MP2120 Datasheet
367Kb / 11P
   2.5A, 5.5V Synchronous Step-Down Switching Regulator
logo
ACE Technology Co., LTD...
ACE713C ACE-ACE713C Datasheet
414Kb / 4P
   High Efficiency 1.25MHz, 2.5A Boost Regulator
VER 1.2
More results


Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18


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