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: LM3352MTCX-3.0
廠商: NATIONAL SEMICONDUCTOR CORP
元件分類: 穩壓器
英文描述: Reed Relay; Contacts:SPDT; Contact Carry Current:0.2A; Coil Voltage DC Max:5V; Relay Terminals:SMT J-Lead; Switching Current Max:0.1A; Switching Voltage Max:30V; Contact Carrying Power:3W; Leaded Process Compatible:Yes RoHS Compliant: Yes
中文描述: SWITCHED CAPACITOR REGULATOR, 1350 kHz SWITCHING FREQ-MAX, PDSO16
封裝: 1.10 MM HEIGHT, TSSOP-16
文件頁數: 8/11頁
文件大小: 516K
代理商: LM3352MTCX-3.0
Filter Capacitor Selection
a) CAPACITOR TECHNOLOGIES
The three major technologies of capacitors that can be used
as filter capacitors for LM3352 are: i) tantalum, ii) ceramic
and iii) polymer electrolytic technologies.
i) Tantalum
Tantalum capacitors are widely used in switching regulators.
Tantalum capacitors have the highest CV rating of any tech-
nology; as a result, high values of capacitance can be ob-
tained in relatively small package sizes. It is also possible to
obtain high value tantalum capacitors in very low profile
(
<
1.2 mm) packages. This makes the tantalums attractive
for low-profile, small size applications. Tantalums also pos-
sess very good temperature stability; i.e., the change in the
capacitance value, and impedance over temperature is rela-
tively small. However, the tantalum capacitors have relatively
high ESR values which can lead to higher voltage ripple and
their frequency stability (variation over frequency) is not very
good, especially at high frequencies (
>
1 MHz).
ii) Ceramic
Ceramic capacitors have the lowest ESR of the three tech-
nologies and their frequency stability is exceptionally good.
These characteristics make the ceramics an attractive
choice for low ripple, high frequency applications. However,
the temperature stability of the ceramics is bad, except for
the X7R and X5R dielectric types. High capacitance values
(
>
1
μF)
are
achievable
Taiyo-yuden which are suitable for use with regulators. Ce-
ramics are taller and larger than the tantalums of the same
capacitance value.
from
companies
such
as
iii) Polymer Electrolytic
Polymer electrolytic is a third suitable technology. Polymer
capacitors provide some of the best features of both the ce-
ramic and the tantalum technologies. They provide very low
ESR values while still achieving high capacitance values.
However, their ESR is still higher than the ceramics, and
their capacitance value is lower than the tantalums of the
same size. Polymers offer good frequency stability (compa-
rable to ceramics) and good temperature stability (compa-
rable to tantalums). The Aluminum Polymer Electrolytics of-
fered by Cornell-Dubilier and Panasonic, and the POSCAPs
offered by Sanyo fall under this category.
Table 1 compares the features of the three capacitor tech-
nologies.
TABLE 1. Comparison of Capacitor Technologies
Ceramic
Tantalum
Polymer
Electrolytic
Low
Low
ESR
Relative Height
Lowest
Low for Small Values (
<
10 μF); Taller for
Higher Values
Large
X7R/X5R-Acceptable
Good
Low
Low
Lowest
High
Lowest
Relative Footprint
Temperature Stability
Frequency Stability
V
OUT
Ripple Magnitude
@
<
50 mA
V
OUT
Ripple Magnitude
@
>
100 mA
dv/dt of V
OUT
Ripple
@
All Loads
Small
Good
Acceptable
High
Slightly Higher
High
Largest
Good
Good
Low
Low
Low
b) CAPACITOR SELECTION
i) Output Capacitor (C
OUT
)
The output capacitor C
directly affects the magnitude of
the output ripple voltage so C
should be carefully se-
lected. The graphs titled V
Ripple vs. C
in the Typical
Performance Characteristics section show how the ripple
voltage magnitude is affected by the C
value and the ca-
pacitor technology. These graphs are taken at the gain at
which worst case ripple is observed. In general, the higher
the value of C
, the lower the output ripple magnitude. At
lighter loads, the low ESR ceramics offer a much lower V
ripple than the higher ESR tantalums of the same value. At
higher loads, the ceramics offer a slightly lower V
ripple
magnitude than the tantalums of the same value. However,
the dv/dt of the V
ripple with the ceramics and polymer
electrolytics is much lower than the tantalums under all load
conditions. The tantalums are suggested for very low profile,
small size applications. The ceramics and polymer electrolyt-
ics are a good choice for low ripple, low noise applications
where size is less of a concern.
ii) Input Capacitor (C
IN
)
The input capacitor C
directly affects the magnitude of the
input ripple voltage, and to a lesser degree the V
ripple.
A higher value C
will give a lower V
ripple. To optimize
low input and output ripple as well as size a 15 μF polymer
electrolytic, 22 μF ceramic, or 33 μF tantalum capacitor is
recommended. This will ensure low input ripple at 200 mA
load current. If lower currents will be used or higher input
ripple can be tolerated then a smaller capacitor may be used
to reduce the overall size of the circuit. The lower ESR ce-
ramics and polymer electrolytics achieve a lower V
ripple
than the higher ESR tantalums of the same value. Tantalums
make a good choice for small size, very low profile applica-
tions. The ceramics and polymer electrolytics are a good
choice for low ripple, low noise applications where size is
less of a concern. The 15 μF polymer electrolytics are physi-
cally much larger than the 33 μF tantalums and 22 μF ceram-
ics.
www.national.com
8
相關PDF資料
PDF描述
LM337LM 3-Terminal Adjustable Regulator
LM337L 3-Terminal Adjustable Regulator
LM337LZ 3-Terminal Adjustable Regulator
LM380 Audio Power Amplifier
LM380N Audio Power Amplifier
相關代理商/技術參數
參數描述
LM3354 制造商:NSC 制造商全稱:National Semiconductor 功能描述:Regulated 90mA Buck-Boost Switched Capacitor DC/DC Converter
LM3354-1.8EVAL 功能描述:BOARD EVALUATION LM3354-1.8 RoHS:否 類別:編程器,開發系統 >> 評估板 - DC/DC 與 AC/DC(離線)SMPS 系列:- 產品培訓模塊:Obsolescence Mitigation Program 標準包裝:1 系列:True Shutdown™ 主要目的:DC/DC,步升 輸出及類型:1,非隔離 功率 - 輸出:- 輸出電壓:- 電流 - 輸出:1A 輸入電壓:2.5 V ~ 5.5 V 穩壓器拓撲結構:升壓 頻率 - 開關:3MHz 板類型:完全填充 已供物品:板 已用 IC / 零件:MAX8969
LM3354-3.7 制造商:TI 制造商全稱:Texas Instruments 功能描述:LM3354-3.7 Regulated 90mA Buck-Boost Switched Capacitor DC/DC Converter
LM3354-37 制造商:NSC 制造商全稱:National Semiconductor 功能描述:Regulated 90mA Buck-Boost Switched Capacitor DC/DC
LM3354-4.1EVAL 功能描述:BOARD EVALUATION LM3354-4.1 RoHS:否 類別:編程器,開發系統 >> 評估板 - DC/DC 與 AC/DC(離線)SMPS 系列:- 產品培訓模塊:Obsolescence Mitigation Program 標準包裝:1 系列:True Shutdown™ 主要目的:DC/DC,步升 輸出及類型:1,非隔離 功率 - 輸出:- 輸出電壓:- 電流 - 輸出:1A 輸入電壓:2.5 V ~ 5.5 V 穩壓器拓撲結構:升壓 頻率 - 開關:3MHz 板類型:完全填充 已供物品:板 已用 IC / 零件:MAX8969
主站蜘蛛池模板: 永和县| 缙云县| 樟树市| 苍山县| 高雄县| 登封市| 监利县| 德令哈市| 平定县| 曲松县| 会宁县| 齐齐哈尔市| 泾阳县| 华阴市| 大宁县| 渝中区| 汉寿县| 邢台县| 阿图什市| 大埔县| 嘉黎县| 北海市| 平塘县| 辛集市| 佛教| 巩留县| 罗定市| 南汇区| 吐鲁番市| 米林县| 西和县| 宁都县| 全州县| 兰溪市| 福建省| 大兴区| 梁平县| 济阳县| 乌兰察布市| 枞阳县| 丹东市|