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参数资料
| 型号： | IR3629 |
| 厂商： | International Rectifier |
| 英文描述： | HIGH FREQUENCY SYNCHRONOUS PWM BUCK CONTROLLER WITH POWER GOOD OUTPUT |
| 中文描述： | 高频同步PWM降压控制器与电源良好输出 |
| 文件页数： | 5/23页 |
| 文件大小： | 598K |
| 代理商： | IR3629 |
IR3629/IR3629A MPbF
11/26/2007
Power MOSFET Selection
The IR3629 uses two N-Channel MOSFETs per
channel. The selection criteria to meet power
transfer requirements are based on maximum
drain-source voltage (V
DSS), gate-source drive
voltage (V
gs),
maximum output current, On-
resistance R
DS(on), and thermal management.
The MOSFET must have a maximum operating
voltage (V
DSS) exceeding the maximum input
voltage (V
in).
The gate drive requirement is almost the same
for both MOSFETs. A logic-level transistor can
be used and caution should be taken with
devices at very low gate threshold voltage (V
gs)
to
prevent
undesired
turn-on
of
the
complementary MOSFET, which results in a
shoot-through current.
The total power dissipation for MOSFETs
includes conduction and switching losses. For
the Buck converter the average inductor current
is equal to the DC load current. The conduction
loss is defined as:
The R
DS(on) temperature dependency should be
considered for the worst case operation. This is
typically given in the MOSFET datasheet. Ensure
that the conduction losses and switching losses
do not exceed the package ratings or violate the
overall thermal budget.
For this design, the IRF7823 is selected for
control FET and IRF7832Z is selected for the
synchronous FET. These devices provide low on
resistance in a cost effective SO8 package.
The MOSFETs have the following data:
The conduction losses will be:
P
con=0.44W. The
switching loss is more difficult to calculate, even
though
the
switching
transition
is
well
understood. The reason is the effect of the
parasitic components and switching times during
the switching procedures such as turn-on / turn-
off delays and rise and fall times. The control
MOSFET contributes to the majority of the
switching
losses
in
a
synchronous
Buck
converter. The synchronous MOSFET turns on
under zero voltage conditions, therefore, the turn
on losses for synchronous MOSFET can be
neglected. With a linear approximation, the total
switching loss can be expressed as:
Where:
V
ds(off) = Drain to source voltage at the off time
t
r = Rise time
t
f = Fall time
T = Switching period
I
load = Load current
The switching time waveforms is shown in
figure12.
From IRF7832Z data sheet:
tr = 13ns
tf = 14ns
These values are taken under a certain test
condition. For more details please refer to the
IRF7832Z data sheet.
By using equation (10), we can calculate the
switching losses.
P
sw=0.74W
The reverse recovery loss is also another
contributing factor in control FET switching
losses. This is equivalent to extra current
required to remove the minority charges from the
synchronous FET. The reverse recovery loss can
be expressed as:
(10)
-
*
)
(
load
f
r
off
ds
sw
I
T
t
V
P
+
=
2
VDS
VGS
10%
90%
td(ON)
td(OFF)
tr
tf
Fig. 12: switching time waveforms
cy
g Frequen
: Switchin
F
ery Time
verse
:
t
e
ery Ch
verse
:
Q
*F
*t
Q
P
s
rr
s
rr
Qrr
cov
Re
arg
cov
Re
=
13
dependency
e
temperatur
R
D)
(1
R
I
switch)
(lower
P
D
R
I
switch)
(upper
P
ds(on)
2
load
cond
ds(on)
2
load
cond
=
=
=
V
m
R
nC
V,Q
V
gs
ds(on)
g
ds
10
7
8
14
30
=
@
.
:
(IRF7823)
ControlFET
V
m
R
nC
V,Q
V
gs
ds(on)
g
ds
10
@
8
.
3
45
30
:
(IRF7832Z)
SyncFET
=
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相关代理商/技术参数 |
参数描述 |
|---|---|
| IR3629A | 制造商:IRF 制造商全称:International Rectifier 功能描述:HIGH FREQUENCY SYNCHRONOUS PWM BUCK CONTROLLER WITH POWER GOOD OUTPUT |
| IR3629AMPBF | 制造商:IRF 制造商全称:International Rectifier 功能描述:HIGH FREQUENCY SYNCHRONOUS PWM BUCK CONTROLLER WITH POWER GOOD OUTPUT |
| IR3629AMTRPBF | 功能描述:电压模式 PWM 控制器 HI FREQ SYNC PWM 600kHz 5 or 12V 0.6 RoHS:否 制造商:Texas Instruments 输出端数量:1 拓扑结构:Buck 输出电压:34 V 输出电流: 开关频率: 工作电源电压:4.5 V to 5.5 V 电源电流:600 uA 最大工作温度:+ 125 C 最小工作温度:- 40 C 封装 / 箱体:WSON-8 封装:Reel |
| IR3629MPBF | 功能描述:IC CTLR PWM BUCK SYNC 12-MLPD RoHS:是 类别:集成电路 (IC) >> PMIC - 稳压器 - 专用型 系列:- 产品培训模块:Lead (SnPb) Finish for COTS Obsolescence Mitigation Program 标准包装:2,000 系列:- 应用:电源，ICERA E400，E450 输入电压:4.1 V ~ 5.5 V 输出数:10 输出电压:可编程 工作温度:-40°C ~ 85°C 安装类型:表面贴装 封装/外壳:42-WFBGA，WLCSP 供应商设备封装:42-WLP 包装:带卷 (TR) |
| IR3629MTRPBF | 功能描述:电压模式 PWM 控制器 HI FREQ SYNC PWM 600kHz 5 or 12V 0.6 RoHS:否 制造商:Texas Instruments 输出端数量:1 拓扑结构:Buck 输出电压:34 V 输出电流: 开关频率: 工作电源电压:4.5 V to 5.5 V 电源电流:600 uA 最大工作温度:+ 125 C 最小工作温度:- 40 C 封装 / 箱体:WSON-8 封装:Reel |
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