công cụ tìm kiếm bảng dữ liệu linh kiện điện tử
  Vietnamese  ▼
ALLDATASHEET.VN

X  

Preview PDF HTML

AN2728 bảng dữ liệu(PDF) 11 Page - STMicroelectronics

tên linh kiện AN2728
Giải thích chi tiết về linh kiện  ST1S12 small synchronous buck converter
PDF  20 Pages
Scroll/Zoom Zoom In 100%  Zoom Out
nhà sản xuất  STMICROELECTRONICS [STMicroelectronics]
Trang chủ  http://www.st.com
Logo STMICROELECTRONICS - STMicroelectronics

AN2728 bảng dữ liệu(HTML) 11 Page - STMicroelectronics

Back Button AN2728 Datasheet HTML 7Page - STMicroelectronics AN2728 Datasheet HTML 8Page - STMicroelectronics AN2728 Datasheet HTML 9Page - STMicroelectronics AN2728 Datasheet HTML 10Page - STMicroelectronics AN2728 Datasheet HTML 11Page - STMicroelectronics AN2728 Datasheet HTML 12Page - STMicroelectronics AN2728 Datasheet HTML 13Page - STMicroelectronics AN2728 Datasheet HTML 14Page - STMicroelectronics AN2728 Datasheet HTML 15Page - STMicroelectronics Next Button
Zoom Inzoom in Zoom Outzoom out
 11 / 20 page
background image
AN2728
Thermal considerations
11/20
3
Thermal considerations
The dissipated power of the device is determined by three different factors:
●
Switch losses due to the non-negligible RDS(on). These are equal to:
Equation 8
and
Equation 9
where D is the duty cycle of the application.
Note:
The duty cycle is theoretically given by the ratio between VOUT and VIN, but in practice it is
significantly higher than this value in order to compensate for the losses of the overall
application. Due to this reason, the switching losses related to the RDS(on) increase
compared to an ideal case.
●
On and off switching losses. These are given by the following relation:
Equation 10
where TON and TOFF are the overlap times of the voltage across the power switch and the
current flowing into it during the turn-on and turnoff phases. TSW is the equivalent switching
time.
●
Quiescent current losses:
Equation 11
where IQ is the quiescent current.
The overall losses are:
Equation 12
When the device operates at VOUT close to VIN (high duty cycle) the power dissipated can
be approximated by:
Equation 13
D
I
R
P
2
OUT
DS(on)_P
ON_P
×
×
=
D
I
R
P
2
OUT
DS(on)_P
ON_P
×
×
=
D)
1
(
I
R
P
2
OUT
DS(on)_N
ON_N
-
×
×
=
D)
1
(
I
R
P
2
OUT
DS(on)_N
ON_N
-
×
×
=
SW
SW
OUT
IN
SW
OFF
ON
OUT
IN
SW
F
T
I
V
F
2
)
T
(T
I
V
P
×
×
×
=
×
+
×
×
=
SW
SW
OUT
IN
SW
OFF
ON
OUT
IN
SW
F
T
I
V
F
2
)
T
(T
I
V
P
×
×
×
=
×
+
×
×
=
PQ = VIN x IQ
Q
IN
SW
SW
OUT
IN
2
OUT
DS(on)_N
2
OUT
DS(on)_P
TOT
I
V
F
T
I
V
D)
1
(
I
R
D
I
R
P
×
+
×
×
×
+
-
×
×
+
×
×
=
Q
IN
SW
SW
OUT
IN
2
OUT
DS(on)_N
2
OUT
DS(on)_P
TOT
I
V
F
T
I
V
D)
1
(
I
R
D
I
R
P
×
+
×
×
×
+
-
×
×
+
×
×
=
Q
IN
2
OUT
DS(ON)_P
TOT
I
V
I
R
P
x
+
x
=
Q
IN
2
OUT
DS(ON)_P
TOT
I
V
I
R
P
x
+
x
=



Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20


bảng dữ liệu tải về

Go To PDF Page


Link URL



Cho đến nay ALLDATASHEET có giúp ích cho doanh nghiệp của bạn hay không?  [ DONATE ] 

Alldatasheet là   |   Quảng cáo   |   Liên lạc với chúng tôi   |   Chính sách bảo mật   |   Liên kết đến bảng dữ liệu    |   Trao đổi link   |   Tìm kiếm theo nhà sản xuất
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