データシートサーチシステム
  Japanese  ▼
ALLDATASHEET.JP

X  

IRLR7843 データシート(PDF) 8 Page - Kersemi Electronic Co., Ltd.

部品番号 IRLR7843
部品情報  High Frequency Synchronous Buck Converters for Computer Processor Power
Download  11 Pages
Scroll/Zoom Zoom In 100%  Zoom Out
メーカー  KERSEMI [Kersemi Electronic Co., Ltd.]
ホームページ  http://www.kersemi.com
Logo KERSEMI - Kersemi Electronic Co., Ltd.

IRLR7843 データシート(HTML) 8 Page - Kersemi Electronic Co., Ltd.

Back Button IRLR7843 Datasheet HTML 3Page - Kersemi Electronic Co., Ltd. IRLR7843 Datasheet HTML 4Page - Kersemi Electronic Co., Ltd. IRLR7843 Datasheet HTML 5Page - Kersemi Electronic Co., Ltd. IRLR7843 Datasheet HTML 6Page - Kersemi Electronic Co., Ltd. IRLR7843 Datasheet HTML 7Page - Kersemi Electronic Co., Ltd. IRLR7843 Datasheet HTML 8Page - Kersemi Electronic Co., Ltd. IRLR7843 Datasheet HTML 9Page - Kersemi Electronic Co., Ltd. IRLR7843 Datasheet HTML 10Page - Kersemi Electronic Co., Ltd. IRLR7843 Datasheet HTML 11Page - Kersemi Electronic Co., Ltd.  
Zoom Inzoom in Zoom Outzoom out
 8 / 11 page
background image
Control FET
Special attention has been given to the power losses
in the switching elements of the circuit - Q1 and Q2.
Power losses in the high side switch Q1, also called
the Control FET, are impacted by the R
ds(on) of the
MOSFET, but these conduction losses are only about
one half of the total losses.
Power losses in the control switch Q1 are given
by;
P
loss = Pconduction+ Pswitching+ Pdrive+ Poutput
This can be expanded and approximated by;
P
loss =
I
rms
2
× R
ds(on )
()
+ I ×
Q
gd
i
g
× V
in × f
 + I ×
Q
gs 2
i
g
× V
in × f
+ Q
g × Vg × f
()
+
Q
oss
2
×V
in × f
This simplified loss equation includes the terms Q
gs2
and Q
oss which are new to Power MOSFET data sheets.
Q
gs2 is a sub element of traditional gate-source
charge that is included in all MOSFET data sheets.
The importance of splitting this gate-source charge
into two sub elements, Q
gs1 and Qgs2, can be seen from
Fig 16.
Q
gs2 indicates the charge that must be supplied by
the gate driver between the time that the threshold
voltage has been reached and the time the drain cur-
rent rises to I
dmax at which time the drain voltage be-
gins to change. Minimizing Q
gs2 is a critical factor in
reducing switching losses in Q1.
Q
oss is the charge that must be supplied to the out-
put capacitance of the MOSFET during every switch-
ing cycle. Figure A shows how Q
oss is formed by the
parallel combination of the voltage dependant (non-
linear) capacitance’s C
ds and Cdg when multiplied by
the power supply input buss voltage.
Synchronous FET
The power loss equation for Q2 is approximated
by;
P
loss = Pconduction + Pdrive + Poutput
*
P
loss =
I
rms
2 × R
ds(on)
()
+ Q
g × Vg × f
()
+
Q
oss
2
× V
in × f
+ Q
rr × Vin × f
(
)
*dissipated primarily in Q1.
For the synchronous MOSFET Q2, R
ds(on) is an im-
portant characteristic; however, once again the im-
portance of gate charge must not be overlooked since
it impacts three critical areas. Under light load the
MOSFET must still be turned on and off by the con-
trol IC so the gate drive losses become much more
significant. Secondly, the output charge Q
oss and re-
verse recovery charge Q
rr both generate losses that
are transfered to Q1 and increase the dissipation in
that device. Thirdly, gate charge will impact the
MOSFETs’ susceptibility to Cdv/dt turn on.
The drain of Q2 is connected to the switching node
of the converter and therefore sees transitions be-
tween ground and V
in. As Q1 turns on and off there is
a rate of change of drain voltage dV/dt which is ca-
pacitively coupled to the gate of Q2 and can induce
a voltage spike on the gate that is sufficient to turn
the MOSFET on, resulting in shoot-through current .
The ratio of Q
gd/Qgs1 must be minimized to reduce the
potential for Cdv/dt turn on.
Power MOSFET Selection for Non-Isolated DC/DC Converters
Figure A: Q
oss Characteristic
IRLR/U7843
www.kersemi.com
8
2014-8-25


同様の部品番号 - IRLR7843

メーカー部品番号データシート部品情報
logo
International Rectifier
IRLR7843 IRF-IRLR7843 Datasheet
202Kb / 11P
   HEXFET Power MOSFET
IRLR7843 IRF-IRLR7843 Datasheet
211Kb / 12P
   High Frequency Synchronous Buck Converters for Computer Processor Power
logo
Inchange Semiconductor ...
IRLR7843 ISC-IRLR7843 Datasheet
336Kb / 2P
   N-Channel MOSFET Transistor
IRLR7843 ISC-IRLR7843 Datasheet
248Kb / 2P
   Isc N-Channel MOSFET Transistor
logo
International Rectifier
IRLR7843CPBF IRF-IRLR7843CPBF Datasheet
298Kb / 11P
   HEXFET Power MOSFET
More results

同様の説明 - IRLR7843

メーカー部品番号データシート部品情報
logo
International Rectifier
IRLU7833-701PBF IRF-IRLU7833-701PBF Datasheet
325Kb / 11P
   High Frequency Synchronous Buck Converters for Computer Processor Power
logo
Kersemi Electronic Co.,...
IRLR7833 KERSEMI-IRLR7833 Datasheet
1Mb / 11P
   High Frequency Synchronous Buck Converters for Computer Processor Power
IRLU8721 KERSEMI-IRLU8721 Datasheet
1Mb / 11P
   High Frequency Synchronous Buck Converters for Computer Processor Power
IRFU3704ZPBF KERSEMI-IRFU3704ZPBF Datasheet
4Mb / 11P
   High Frequency Synchronous Buck Converters for Computer Processor Power
IRFU3707ZPBF KERSEMI-IRFU3707ZPBF Datasheet
4Mb / 11P
   High Frequency Synchronous Buck Converters for Computer Processor Power
IRF3704ZS KERSEMI-IRF3704ZS Datasheet
1Mb / 11P
   High Frequency Synchronous Buck Converters for Computer Processor Power
IRF3704ZL KERSEMI-IRF3704ZL Datasheet
1Mb / 11P
   High Frequency Synchronous Buck Converters for Computer Processor Power
logo
International Rectifier
IRF3707ZPBF IRF-IRF3707ZPBF_15 Datasheet
393Kb / 12P
   High Frequency Synchronous Buck Converters for Computer Processor Power
logo
Kersemi Electronic Co.,...
IRFR3709ZPBF KERSEMI-IRFR3709ZPBF Datasheet
4Mb / 11P
   High Frequency Synchronous Buck Converters for Computer Processor Power
IRFR3709ZTRR KERSEMI-IRFR3709ZTRR Datasheet
4Mb / 11P
   High Frequency Synchronous Buck Converters for Computer Processor Power
More results


Html Pages

1 2 3 4 5 6 7 8 9 10 11


データシート ダウンロード

Go To PDF Page


リンク URL




プライバシーポリシー
ALLDATASHEET.JP
ALLDATASHEETはお客様のビジネスに役立ちますか?  [ DONATE ] 

Alldatasheetは   |   広告   |   お問い合わせ   |   プライバシーポリシー   |   リンク交換   |   メーカーリスト
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