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参数资料
| 型号： | LTC4080EMSE |
| 厂商： | LINEAR TECHNOLOGY CORP |
| 元件分类： | 稳压器 |
| 英文描述： | 0.8 A BATTERY CHARGE CONTROLLER, 2750 kHz SWITCHING FREQ-MAX, PDSO10 |
| 封装： | PLASTIC, MSOP-10 |
| 文件页数： | 10/20页 |
| 文件大小： | 288K |
| 代理商： | LTC4080EMSE |
LTC4080
18
4080fa
APPLICATIO S I FOR ATIO
WU
U
reasonable starting point for setting ripple current is
ΔIL
=0.3 ILIM, where ILIM is the peak switch current limit.
The largest ripple current occurs at the maximum input
voltage. To guarantee that the ripple current stays below a
specied maximum, the inductor value should be chosen
according to the following equation:
L
V
fI
V
OUT
L
OUT
IN MAX
≥
()
0
1
For applications with VOUT = 1.8V, the above equation
suggests that an inductor of at least 6.8H should be used
for proper operation.
Many different sizes and shapes of inductors are
available from numerous manufacturers. To maximize
efciency, choose an inductor with a low DC resistance.
Keep in mind that most inductors that are very thin or
have a very small volume typically have much higher
core and DCR losses and will not give the best efciency.
Also choose an inductor with a DC current rating at least
1.5 times larger than the peak inductor current limit to
ensure that the inductor does not saturate during nor-
mal operation. To minimize radiated noise, use a toroid,
or shielded pot core inductors in ferrite or permalloy
materials. Table 1 shows a list of several inductor manu-
facturers.
Table 1. Recommended Surface Mount Inductor Manufacturers
Coilcraft
www.coilcraft.com
Sumida
www.sumida.com
Murata
www.murata.com
Toko
www.tokoam.com
Input and Output Capacitor Selection
Since the input current waveform to a buck converter is a
square wave, it contains very high frequency components.
It is strongly recommended that a low equivalent series
resistance (ESR) multilayer ceramic capacitor be used to
bypass the BAT pin which is the input for the converter.
Tantalum and aluminum capacitors are not recommended
because of their high ESR. The value of the capacitor on
BAT directly controls the amount of input voltage ripple for
a given load current. Increasing the size of this capacitor
will reduce the input ripple.
To prevent large VOUT voltage steps during transient
load conditions, it is also recommended that a ceramic
capacitor be used to bypass VOUT. The typical value for
this capacitor is 4.7F.
Multilayer Ceramic Chip Capacitors (MLCC) typically have
exceptional ESR performance. MLCCs combined with a
carefully laid out board with an unbroken ground plane will
yield very good performance and low EMI emissions.
There are several types of ceramic capacitors with con-
siderably different characteristics. Y5V and X5R ceramic
capacitors have apparently higher packing density but
poor performance over their rated voltage or temperature
ranges. Under given voltage and temperature conditions,
Y5V, X5R and X7R ceramic capacitors should be com-
pared directly by case size rather than specied value for
a desired minimum capacitance. Some manufacturers
provide excellent data on their websites about achiev-
able capacitance. Table 2 shows a list of several ceramic
capacitor manufacturers.
Table 2. Recommended Ceramic Capacitor Manufacturers
Taiyo Yuden
www.t-yuden.com
AVX
www.avxcorp.com
Murata
www.murata.com
TDK
www.tdk.com
Board Layout Considerations
To be able to deliver maximum charge current under all
conditions, it is critical that the exposed metal pad on the
backside of the LTC4080’s package has a good thermal
contact to the PC board ground. Correctly soldered to a
2500mm2 double-sided 1 oz. copper board, the LTC4080
has a thermal resistance of approximately 43°C/W. Failure
to make thermal contact between the exposed pad on the
backside of the package and the copper board will result
in thermal resistances far greater than 43°C/W.
Furthermore due to its high frequency switching circuitry,
it is imperative that the input capacitor, BAT pin capaci-
tor, inductor, and the output capacitor be as close to the
LTC4080 as possible and that there is an unbroken ground
plane under the LTC4080 and all of its high frequency
components.
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| LTC4080EMSE#PBF | 功能描述:IC CHARGER LI-ION 10-MSOP RoHS:是 类别:集成电路 (IC) >> PMIC - 电池管理 系列:- 标准包装:61 系列:- 功能:电源管理 电池化学:锂离子（Li-Ion）、锂聚合物（Li-Pol） 电源电压:4.35 V ~ 5.5 V 工作温度:-40°C ~ 85°C 安装类型:表面贴装 封装/外壳:22-WFDFN 裸露焊盘 供应商设备封装:22-DFN（6x3）裸露焊盘 包装:管件 |
| LTC4080EMSE#TRPBF | 功能描述:IC CHARGER LI-ION 10-MSOP RoHS:是 类别:集成电路 (IC) >> PMIC - 电池管理 系列:- 标准包装:61 系列:- 功能:电源管理 电池化学:锂离子（Li-Ion）、锂聚合物（Li-Pol） 电源电压:4.35 V ~ 5.5 V 工作温度:-40°C ~ 85°C 安装类型:表面贴装 封装/外壳:22-WFDFN 裸露焊盘 供应商设备封装:22-DFN（6x3）裸露焊盘 包装:管件 |
| LTC4080EMSE-PBF | 制造商:LINER 制造商全称:Linear Technology 功能描述:500mA Standalone Li-Ion Charger with Integrated 300mA Synchronous Buck |
| LTC4080EMSE-TRPBF | 制造商:LINER 制造商全称:Linear Technology 功能描述:500mA Standalone Li-Ion Charger with Integrated 300mA Synchronous Buck |
| LTC4080X | 制造商:LINER 制造商全称:Linear Technology 功能描述:500mA Standalone Li-Ion Charger with Integrated 300mA Synchronous Buck in 3mm × 3mm DFN |
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