參數(shù)資料
型號: LM3207TL
廠商: NATIONAL SEMICONDUCTOR CORP
元件分類: 穩(wěn)壓器
英文描述: 650mA Miniature, Adjustable, Step-Down DC-DC Converter for RF Power Amplifiers with Integrated Vref LDO
中文描述: 1.2 A SWITCHING REGULATOR, 2300 kHz SWITCHING FREQ-MAX, BGA9
封裝: MICRO SMD, 9 PIN
文件頁數(shù): 17/19頁
文件大?。?/td> 1335K
代理商: LM3207TL
Application Information
(Continued)
wide, for a section approximately 6mil long or longer, to
provide thermal relief. Each trace should then neck up or
down to its optimal width. The important criterion is symme-
try. This ensures the solder bumps re-flow evenly and that
the device solders level to the board. In particular, special
attention must be paid to the pads for bumps A1, A3 and B3.
Because P
GND
and PV
IN
are typically connected to large
copper planes, inadequate thermal relief’s may result in late
or inadequate re-flow of these bumps. The Micro SMD pack-
age is optimized for the smallest possible size in applications
with red or infrared opaque cases. Because the Micro SMD
package lacks the plastic encapsulation characteristic of
larger devices, it is vulnerable to light. Backside metalization
and/or epoxy coating, along with front-side shading by the
printed circuit board, reduce this sensitivity. However, the
package has exposed die edges. Micro SMD devices are
sensitive to light, in the red and infrared range, shining on the
package’s exposed die edges.
BOARD LAYOUT CONSIDERATIONS
Referring to
Figure 4
, the LM3207 has two major current
loops where pulse and ripple current flow. The loop shown in
the left hand side is most important, because pulse current
shown in
Figure 4
flows in this path. The right hand side is
next. The current waveform in this path is triangular, as
shown in
Figure 4
. Pulse current has many high-frequency
components due to fast di/dt. Triangular ripple current also
has wide high-frequency components. Board layout and cir-
cuit pattern design of these two loops are the key factors for
reducing noise radiation and stable operation. Other lines,
such as from battery to C1(+) and C2(+) to load, are almost
DC current, so it is not necessary to take so much care. Only
pattern width (current capability) and DCR drop consider-
ations are needed.
20165354
FIGURE 4. Current Loop
L
www.national.com
17
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相關代理商/技術參數(shù)
參數(shù)描述
LM3207TL/NOPB 功能描述:DC/DC 開關控制器 RoHS:否 制造商:Texas Instruments 輸入電壓:6 V to 100 V 開關頻率: 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 安裝風格: 封裝 / 箱體:CPAK
LM3207TL-2.53 制造商:NSC 制造商全稱:National Semiconductor 功能描述:650mA Miniature, Adjustable, Step-Down DC-DC Converter for RF Power Amplifiers with Integrated Vref LDO
LM3207TL-2.53/NOPB 功能描述:DC/DC 開關控制器 RoHS:否 制造商:Texas Instruments 輸入電壓:6 V to 100 V 開關頻率: 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 安裝風格: 封裝 / 箱體:CPAK
LM3207TL-2.53EV 功能描述:電源管理IC開發(fā)工具 LM3207TL-2.53 EVAL BOARD RoHS:否 制造商:Maxim Integrated 產(chǎn)品:Evaluation Kits 類型:Battery Management 工具用于評估:MAX17710GB 輸入電壓: 輸出電壓:1.8 V
LM3207TLEV 功能描述:電源管理IC開發(fā)工具 LM3207TL EVAL BOARD RoHS:否 制造商:Maxim Integrated 產(chǎn)品:Evaluation Kits 類型:Battery Management 工具用于評估:MAX17710GB 輸入電壓: 輸出電壓:1.8 V