參數(shù)資料
型號(hào): SP6134HVLED
英文描述: Illuminated panel mount pushbutton switch with standard red, green and yellow LED options
中文描述: 評(píng)估板手冊(cè)
文件頁數(shù): 8/14頁
文件大?。?/td> 141K
代理商: SP6134HVLED
8
Date: 5/25/04
SP6134 Dual Supply, Synchronous Buck Controller Copyright 2004 Sipex Corporation
APPLICATIONS INFORMATION
Inductor Selection
There are many factors to consider in selecting
the inductor including cost, efficiency, size and
EMI. In a typical SP6134 circuit, the inductor is
chosen primarily for value, saturation current
and DC resistance. Increasing the inductor value
will decrease output voltage ripple, but degrade
transient response. Low inductor values provide
the smallest size, but cause large ripple currents,
poor efficiency and more output capacitance to
smooth out the larger ripple current. The induc-
tor must also be able to handle the peak current
at the switching frequency without saturating,
and the copper resistance in the winding should
be kept as low as possible to minimize resistive
power loss. A good compromise between size,
loss and cost is to set the inductor ripple current
to be within 20% to 40% of the maximum output
current.
The switching frequency and the inductor oper-
ating point determine the inductor value as fol-
lows:
(max)
(max)
(max)
K
)
(
OUT
r
S
IN
OUT
IN
F
OUT
I
V
V
V
V
L
=
where:
Fs = switching frequency
Kr = ratio of the ac inductor ripple current to the
maximum output current
The peak to peak inductor ripple current is:
L
F
V
V
V
(
V
I
S
IN
OUT
IN
OUT
PP
(max)
(max)
)
=
Once the required inductor value is selected, the
proper selection of core material is based on
peak inductor current and efficiency require-
ments. The core must be large enough not to
saturate at the peak inductor current
2
(max)
PP
OUT
PEAK
I
I
I
+
=
and provide low core loss at the high switching
frequency. Low cost powdered iron cores have
a gradual saturation characteristic but can intro-
duce considerable ac core loss, especially when
the inductor value is relatively low and the
ripple current is high. Ferrite materials, on the
other hand, are more expensive and have an
abrupt saturation characteristic with the induc-
tance dropping sharply when the peak design
current is exceeded. Nevertheless, they are pre-
ferred at high switching frequencies because
they present very low core loss and the design
only needs to prevent saturation. In general,
ferrite or molypermalloy materials are better
choice for all but the most cost sensitive appli-
cations.
The power dissipated in the inductor is equal to
the sum of the core and copper losses. To mini-
mize copper losses, the winding resistance needs
to be minimized, but this usually comes at the
expense of a larger inductor. Core losses have a
more significant contribution at low output cur-
rent where the copper losses are at a minimum,
and can typically be neglected at higher output
currents where the copper losses dominate. Core
loss information is usually available from the
magnetic vendor.
The copper loss in the inductor can be calculated
using the following equation:
I
P
(
)
(
=
WINDING
R
RMS
L
Cu
L
2
)
where
I
L(RMS)
is the RMS inductor current that
can be calculated as follows:
I
L(RMS)
= I
OUT(max)
1 + 1
(
I
PP
)
2
3 I
OUT(max)
相關(guān)PDF資料
PDF描述
SP6134HVLEDEB Evaluation Board Manual
SP6222 50mA and 150mA CMOS Linear Regulators
SP6222EC5-L 50mA and 150mA CMOS Linear Regulators
SP6222EK-L 50mA and 150mA CMOS Linear Regulators
SP6223 50mA and 150mA CMOS Linear Regulators
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
SP6134HVLEDEB 功能描述:電源管理IC開發(fā)工具 Dual Supply Sync Buck Controller RoHS:否 制造商:Maxim Integrated 產(chǎn)品:Evaluation Kits 類型:Battery Management 工具用于評(píng)估:MAX17710GB 輸入電壓: 輸出電壓:1.8 V
SP6136 制造商:SIPEX 制造商全稱:Sipex Corporation 功能描述:Evaluation Board Manual
SP6136_06 制造商:SIPEX 制造商全稱:Sipex Corporation 功能描述:Evaluation Board Manual
SP6136EB 功能描述:DC/DC 開關(guān)控制器 Synchronous Buck Controller RoHS:否 制造商:Texas Instruments 輸入電壓:6 V to 100 V 開關(guān)頻率: 輸出電壓:1.215 V to 80 V 輸出電流:3.5 A 輸出端數(shù)量:1 最大工作溫度:+ 125 C 安裝風(fēng)格: 封裝 / 箱體:CPAK
SP6136ER1 制造商:SIPEX 制造商全稱:Sipex Corporation 功能描述:Evaluation Board Manual