參數(shù)資料
型號: LM3208TLX
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
中文描述: 1.2 A SWITCHING REGULATOR, 2200 kHz SWITCHING FREQ-MAX, PBGA8
封裝: ROHS COMPLIANT, THIN MICRO SMD, 8 PIN
文件頁數(shù): 12/17頁
文件大?。?/td> 1651K
代理商: LM3208TLX
Block Diagram
Operation Description
The LM3208 is a simple, step-down DC-DC converter opti-
mized for powering RF power amplifiers (PAs) in mobile
phones, portable communicators, and similar battery pow-
ered RF devices. It is designed to allow the RF PAto operate
at maximum efficiency over a wide range of power levels
from a single Li-Ion battery cell. It is based on a current-
mode buck architecture, with synchronous rectification for
high efficiency. It is designed for a maximum load capability
of 650mA when V
>
1.05V (typ.) and 400mA when V
OUT
<
1.00V (typ.) in PWM mode.
Maximum load range may vary from this depending on input
voltage, output voltage and the inductor chosen.
Efficiency is typically around 95% for a 400mAload with 3.4V
output, 3.9V input. The LM3208 has an R
DSON
management
scheme to increase efficiency when V
1V. The output
voltage is dynamically programmable from 0.8V to 3.6V by
adjusting the voltage on the control pin without the need for
external feedback resistors. This prolongs battery life by
changing the PA supply voltage dynamically depending on
its transmitting power.
Additional features include current overload protection and
thermal overload shutdown.
The LM3208 is constructed using a chip-scale 8-pin micro
SMD package. This package offers the smallest possible
size, for space-critical applications such as cell phones,
where board area is an important design consideration. Use
of a high switching frequency (2MHz, typ.) reduces the size
of external components. As shown in
Figure 1
, only three
external power components are required for implementation.
Use of a micro SMD package requires special design con-
siderations for implementation. (See Micro SMD Package
Assembly and use in the Applications Information section.)
Its fine bump-pitch requires careful board design and preci-
sion assembly equipment. Use of this package is best suited
for opaque-case applications, where its edges are not sub-
ject to high-intensity ambient red or infrared light. In addition,
the system controller should set EN low during power-up and
other low supply voltage conditions. (See Shutdown Mode in
the Device Information section.)
20166304
FIGURE 2. Functional Block Diagram
L
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LM3208TLX/NOPB 功能描述:DC/DC 開關(guān)控制器 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
LM3208UR/NOPB 功能描述:DC/DC 開關(guān)控制器 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
LM3208URX/NOPB 功能描述:DC/DC 開關(guān)控制器 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
LM3209-G3 制造商:TI 制造商全稱:Texas Instruments 功能描述:LM3209-G3 PRODUCT BRIEF Seamless-Transition Buck-Boost Converter for Battery- Powered 3G/4G RF Power Amplifiers
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