- 您現(xiàn)在的位置：買賣IC網(wǎng) > PDF目錄44552 > LM3420M5-8.4/NOPB (NATIONAL SEMICONDUCTOR CORP) 1-CHANNEL POWER SUPPLY SUPPORT CKT, PDSO5 PDF資料下載
參數(shù)資料
| 型號： | LM3420M5-8.4/NOPB |
| 廠商： | NATIONAL SEMICONDUCTOR CORP |
| 元件分類： | 電源管理 |
| 英文描述： | 1-CHANNEL POWER SUPPLY SUPPORT CKT, PDSO5 |
| 封裝： | MINIATURE, SOT-23, 5 PIN |
| 文件頁數(shù)： | 4/17頁 |
| 文件大?。?/td> | 441K |
| 代理商： | LM3420M5-8.4/NOPB |
V
REG External Voltage Trim
(Continued)
Formulas for selecting trim resistor values are shown below,
based on the percent of increase (%incr) or percent of
decrease (%decr) of the output voltage from the nominal
voltage.
For LM3420-4.2
R
increase = 22x10
5/%incr
R
decrease = (53x10
5/%decr) 75x103
For LM3420-8.2
R
increase = 26x10
5/%incr
R
decrease = (150x10
5/%decr) 176x103
For LM3420-8.4
R
increase = 26x10
5/%incr
R
decrease = (154x10
5/%decr) 181x103
For LM3420-12.6
R
increase = 28x10
5/%incr
R
decrease = (259x10
5/%decr) 287x103
For LM3420-16.8
R
increase = 29x10
5/%incr
R
decrease = (364x10
5/%decr) 392x103
Application Information
The LM3420 regulator/driver provides the reference and
feedback drive functions for a Lithium-Ion battery charger. It
can be used in many different charger configurations using
both linear and switching topologies to provide the precision
needed for charging Lithium-Ion batteries safely and effi-
ciently. Output voltage tolerances better than 0.5% are pos-
sible without using trim pots or precision resistors. The cir-
cuits shown are designed for 2 cell operation, but they can
readily be changed for either 1, 3 or 4 cell charging applica-
tions.
One item to keep in mind when designing with the LM3420 is
that there are parasitic diodes present. In some designs,
under special electrical conditions, unwanted currents may
flow. Parasitic diodes exist from OUT to IN, as well as from
GROUND to IN. In both instances the diode arrow is pointed
toward the IN pin.
Application Circuits
The circuit shown in Figure 5 performs constant-current,
constant-voltage charging of two Li-Ion cells. At the begin-
ning of the charge cycle, when the battery voltage is less
than 8.4V, the LM3420 sources no current from the OUT pin,
keeping Q2 off, thus allowing the LM317 Adjustable voltage
regulator to operate as a constant-current source. (The
LM317 is rated for currents up to 1.5A, and the LM350 and
LM338 can be used for higher currents.) The LM317 forces
a constant 1.25V across R
LIM, thus generating a constant
current of
I
LIM = 1.25V/RLIM
01235909
Increasing V
REG
01235910
Decreasing V
REG
FIGURE 4. Changing V
REG
01235901
FIGURE 5. Constant Current/Constant Voltage Li-Ion Battery Charger
LM3420-4.2/LM3420-8.2/LM3420-8.4/LM3420-12.6/LM3420-16.8
www.national.com
12
相關(guān)PDF資料 |
PDF描述 |
|---|---|
| LM3420M5-8.2/NOPB | 1-CHANNEL POWER SUPPLY SUPPORT CKT, PDSO5 |
| LM3420AM5X-8.4/NOPB | 1-CHANNEL POWER SUPPLY SUPPORT CKT, PDSO5 |
| LM3460-1.5MWC | 1-OUTPUT THREE TERM VOLTAGE REFERENCE, 1.5 V, UUC |
| LM3460-1.2MDC | 1-OUTPUT THREE TERM VOLTAGE REFERENCE, 1.22 V, UUC |
| LM34919BTL | SWITCHING REGULATOR, PBGA10 |
相關(guān)代理商/技術(shù)參數(shù) |
參數(shù)描述 |
|---|---|
| LM3420M5X-12.6 | 功能描述:IC CTRLR LI-ION BAT CHRG SOT23-5 RoHS:是 類別:集成電路 (IC) >> PMIC - 電池管理 系列:- 標(biāo)準(zhǔn)包裝:1 系列:- 功能:充電管理 電池化學(xué):鋰離子（Li-Ion）、鋰聚合物（Li-Pol） 電源電壓:3.75 V ~ 6 V 工作溫度:-40°C ~ 85°C 安裝類型:表面貼裝 封裝/外殼:SC-74A，SOT-753 供應(yīng)商設(shè)備封裝:SOT-23-5 包裝:剪切帶 (CT) 產(chǎn)品目錄頁面:669 (CN2011-ZH PDF) 其它名稱:MCP73831T-2ACI/OTCT |
| LM3420M5X-16.8 | 功能描述:IC CTRLR LI-ION BAT CHRG SOT23-5 RoHS:是 類別:集成電路 (IC) >> PMIC - 電池管理 系列:- 標(biāo)準(zhǔn)包裝:1 系列:- 功能:充電管理 電池化學(xué):鋰離子（Li-Ion）、鋰聚合物（Li-Pol） 電源電壓:3.75 V ~ 6 V 工作溫度:-40°C ~ 85°C 安裝類型:表面貼裝 封裝/外殼:SC-74A，SOT-753 供應(yīng)商設(shè)備封裝:SOT-23-5 包裝:剪切帶 (CT) 產(chǎn)品目錄頁面:669 (CN2011-ZH PDF) 其它名稱:MCP73831T-2ACI/OTCT |
| LM3420M5X-4.2 | 功能描述:IC CTRLR LI-ION BAT CHRG SOT23-5 RoHS:是 類別:集成電路 (IC) >> PMIC - 電池管理 系列:- 標(biāo)準(zhǔn)包裝:1 系列:- 功能:充電管理 電池化學(xué):鋰離子（Li-Ion）、鋰聚合物（Li-Pol） 電源電壓:3.75 V ~ 6 V 工作溫度:-40°C ~ 85°C 安裝類型:表面貼裝 封裝/外殼:SC-74A，SOT-753 供應(yīng)商設(shè)備封裝:SOT-23-5 包裝:剪切帶 (CT) 產(chǎn)品目錄頁面:669 (CN2011-ZH PDF) 其它名稱:MCP73831T-2ACI/OTCT |
| LM3420M5X-8.2 | 功能描述:IC CTRLR LI-ION BAT CHRG SOT23-5 RoHS:是 類別:集成電路 (IC) >> PMIC - 電池管理 系列:- 標(biāo)準(zhǔn)包裝:1 系列:- 功能:充電管理 電池化學(xué):鋰離子（Li-Ion）、鋰聚合物（Li-Pol） 電源電壓:3.75 V ~ 6 V 工作溫度:-40°C ~ 85°C 安裝類型:表面貼裝 封裝/外殼:SC-74A，SOT-753 供應(yīng)商設(shè)備封裝:SOT-23-5 包裝:剪切帶 (CT) 產(chǎn)品目錄頁面:669 (CN2011-ZH PDF) 其它名稱:MCP73831T-2ACI/OTCT |
| LM3420M5X-8.4 | 功能描述:電池管理 RoHS:否 制造商:Texas Instruments 電池類型:Li-Ion 輸出電壓:5 V 輸出電流:4.5 A 工作電源電壓:3.9 V to 17 V 最大工作溫度:+ 85 C 最小工作溫度:- 40 C 封裝 / 箱體:VQFN-24 封裝:Reel |
發(fā)布緊急采購，3分鐘左右您將得到回復(fù)。