欧美成人免费电影,国产欧美一区二区三区精品酒店,精品国产a毛片,色网在线免费观看

參數資料
型號: SC2463TSTRT
廠商: Semtech
文件頁數: 16/23頁
文件大小: 459K
描述: IC REG QD BCK/LINEAR 28TSSOP
標準包裝: 1
拓撲: 降壓(降壓)同步(2),線性(LDO)(2)
功能: 任何功能
輸出數: 4
頻率 - 開關: 600kHz
電壓/電流 - 輸出 1: 控制器
電壓/電流 - 輸出 2: 控制器
電壓/電流 - 輸出 3: 控制器
帶 LED 驅動器:
帶監控器:
帶序列發生器:
電源電壓: 4.5 V ~ 30 V
工作溫度: -40°C ~ 105°C
安裝類型: 表面貼裝
封裝/外殼: 28-TSSOP(0.173",4.40mm 寬)
供應商設備封裝: 28-TSSOP
包裝: 標準包裝
產品目錄頁面: 1358 (CN2011-ZH PDF)
其它名稱: SC2463TSDKR
16
?2007 Semtech Corp.
www.semtech.com
SC2463
POWER MANAGEMENT
Applications Information (Cont.)
 
.
f
V
I
)
1
)(
t
t
(
P
s
in
o
2
f
r
2
1
ts
?/DIV>
+
+
=
where t
r
 is the rise time and t
f
 is the fall time of the
switching process. Different manufactures have different
definitions and test conditions for t
r
 and t
f
. To clarify
these, we sketch the typical MOSFET switching
characteristics under clamped inductive mode in Figure
6.
Figure 6. MOSFET switching characteristics
Where,
Q
gs1
 is the gate charge needed to bring the gate-to-source
voltage V
gs
 to the threshold voltage V
gs_th
,
Q
gs2
 is the additional gate charge required for the switch
current to reach its full-scale value I
ds
.
and
Q
gd
 is the charge needed to charge gate-to-drain (Miller)
capacitance when V
ds
 is falling.
Switching losses occur during the time interval [t
1
, t
3
].
Defining t
r
= t
3
-t
1
 and t
r
 can be approximated as
.
V
V
R
)
Q
Q
(
t
gsp
cc
gt
gd
2
gs
r

+
=
where R
gt
 is the total resistance from the driver supply
rail to the gate of the MOSFET. It includes the gate driver
internal impedance R
gi
, external resistance R
ge
 and the
gate resistance R
g
within the MOSFET i.e.
  R
gt
= R
gi
+R
ge
+R
g
.
V
gsp
 is the Miller plateau voltage shown in Figure 11.
Similarly an approximate expression for t
f
 is
.
V
R
)
Q
Q
(
t
gsp
gt
gd
2
gs
f
+
=
Only a portion of the total losses P
g
= Q
g
V
cc
f
s
 is dissipated
in the MOSFET package. Here Q
g
 is the total gate charge
specified in the datasheet. The power dissipated within
the MOSFET package is
 
.
f
V
Q
R
R
P
s
cc
g
gt
g
tg
=
The total power loss of the top switch is then
  P
t
= P
tc
+P
ts
+P
tg
.
If the input supply of the power converter varies
over a wide range, then it will be necessary to weigh
the relative importance of conduction and switching
losses. This is because conduction losses are inversely
proportional to the input voltage. Switching loss how-
ever increases with the input voltage. The total power
loss of MOSFET should be calculated and compared for
high-line and low-line cases. The worst case is then
used for thermal design.
Bottom Switch:
The RMS current in bottom switch can be shown to be
.
)
1
)(
D
1
(
I
I
12
o
rms
,
2
Q
2
?/DIV>
+

=
The conduction losses are then
    P
bc
=I
Q2,rms
2
R
ds(on)
.
where R
ds(on)
 is the channel resistance of bottom MOSFET.
If the input voltage to output voltage ratio is high (e.g.
V
in
=12V, V
o
=1.5V), the duty ratio D will be small. Since
the bottom switch conducts with duty ratio (1-D), the
corresponding conduction losses can be quite high.
Due to non-overlapping conduction between the top and
the bottom MOSFETs, the internal body diode or the
external Schottky diode across the drain and source
terminals always conducts prior to the turn on of the
bottom MOSFET. The bottom MOSFET switches on with
only a diode voltage between its drain and source
terminals. The switching loss
s
d
o
2
f
r
2
1
bs
f
V
I
)
1
)(
t
t
(
P
?/DIV>
+
+
=
is negligible due to near zero-voltage switching.
The gate losses are estimated as
.
f
V
Q
R
R
P
s
cc
g
gt
g
bg
=
The total bottom switch losses are then
  P
b
=P
bc
+P
bs
+P
bg
.
相關PDF資料
PDF描述
SC338AIMSTRT IC REG CTRLR DUAL POS ADJ 10MSOP
SC402BMLTRT IC REG DL BCK/LINEAR SYNC 32MLPQ
SC403MLTRT IC REG DL BCK/LINEAR SYNC 32MLPQ
SC418ULTRT IC REG DL BUCK/LINEAR 20MLPQ
SC424MLTRT IC REG DL BUCK/LINEAR 28MLPQ
相關代理商/技術參數
參數描述
SC24-681-R 功能描述:INDUCTOR SHIELD 680UH 40MA SMD RoHS:是 類別:電感器,線圈,扼流圈 >> 固定式 系列:SC24 標準包裝:500 系列:1331 電感:1.2µH 電流:247mA 電流 - 飽和:247mA 電流 - 溫升:- 類型:鐵芯體 容差:±10% 屏蔽:屏蔽 DC 電阻(DCR):最大 730 毫歐 Q因子@頻率:40 @ 7.9MHz 頻率 - 自諧振:130MHz 材料 - 芯體:鐵 封裝/外殼:0.312" L x 0.115" W x 0.135" H(7.94mm x 2.92mm x 3.43mm) 安裝類型:表面貼裝 包裝:帶卷 (TR) 工作溫度:-55°C ~ 105°C 頻率 - 測試:7.9MHz
SC246B 制造商:Genteq 功能描述: 制造商:GENTEQ / GE 功能描述:
SC246D 制造商:未知廠家 制造商全稱:未知廠家 功能描述:TRIAC|400V V(DRM)|10A I(T)RMS|TO-203AA
SC246M 制造商:未知廠家 制造商全稱:未知廠家 功能描述:TRIAC|600V V(DRM)|10A I(T)RMS|TO-203AA
SC2475 制造商:SYSTEMSENSOR 制造商全稱:SYSTEMSENSOR 功能描述:Strobes and Horn Strobes
主站蜘蛛池模板: 武冈市| 额济纳旗| 德江县| 永兴县| 若羌县| 内乡县| 黄陵县| 勐海县| 安图县| 巫山县| 禄劝| 称多县| 加查县| 德清县| 永嘉县| 临城县| 高密市| 博兴县| 宣威市| 高淳县| 抚宁县| 章丘市| 巴马| 沽源县| 汝州市| 吴旗县| 旬邑县| 任丘市| 岳西县| 上思县| 永川市| 环江| 安康市| 鄂州市| 桑日县| 宁远县| 卢湾区| 德令哈市| 雷波县| 土默特左旗| 贺兰县|