- 您現(xiàn)在的位置：買賣IC網(wǎng) > PDF目錄44995 > LTC4071EMS8E#TRPBF (LINEAR TECHNOLOGY CORP) 1-CHANNEL POWER SUPPLY SUPPORT CKT, PDSO8 PDF資料下載
參數(shù)資料
| 型號： | LTC4071EMS8E#TRPBF |
| 廠商： | LINEAR TECHNOLOGY CORP |
| 元件分類： | 電源管理 |
| 英文描述： | 1-CHANNEL POWER SUPPLY SUPPORT CKT, PDSO8 |
| 封裝： | LEAD FREE, PLASTIC, MSOP-8 |
| 文件頁數(shù)： | 2/18頁 |
| 文件大小： | 219K |
| 代理商： | LTC4071EMS8E#TRPBF |
LTC4071
10
4071fb
applicaTions inForMaTion
adapter voltage (VWALL) is 12V and the maximum charge
current is calculated as:
IMAX_CHARGE =
VWALL VBAT_MIN
(
)
RIN
=
12V 3.2V
(
)
162Ω
= 54mA
Figure 3. 2-Cell Battery Charger
Care must be taken in selecting the input resistor. Power
dissipated in RIN under full charge current is given by the
following equation:
PDISS =
VWALL VBAT_MIN
(
)
2
RIN
=
12V 3.2V
(
)
2
162Ω
= 0.48W
The charge current decreases as the battery voltage
increases. If the battery voltage is 40mV less than the
programmed float voltage the LTC4071 consumes only
550nA of current, and all of the excess input current flows
into the battery. As the battery voltage reaches the float
voltage, the LTC4071 shunts current from the wall adapter
and regulates the battery voltage to VFLOAT = VCC. The
more shunt current the LTC4071 sinks, the less charge
current the battery gets. Eventually, the LTC4071 shunts
all the current flowing through RIN; up to the maximum
shunt current. The maximum shunt current in this case,
withnoNTCadjustmentisdeterminedbytheinputresistor
and is calculated as:
ISHUNT_MAX =
VWALL VFLOAT
(
)
RIN
=
12V 4.1V
(
)
162Ω
= 49mA
At this point the power dissipated in the input resistor is
388mW.
The LTC4071 can also be used to regulate series-con-
nected battery stacks as illustrated in Figure 3. Here two
LTC4071devicesareusedtochargetwobatteriesinseries.
A single resistor sets the maximum charge/shunt current.
LTC4071
BAT
RIN
GND
Li-Ion
BATTERY
VCC
+
1F
4071 F03
LTC4071
BAT
GND
Li-Ion
BATTERY
VCC
+
1F
WALL
ADAPTER
General Charging Considerations
The LTC4071 uses a different charging methodology from
previous chargers. Most Li-Ion chargers terminate the
charging after a period of time. The LTC4071 does not have
a discrete charge termination. Extensive measurements
on Li-Ion cells show that the cell charge current drops
to very low levels with the shunt charge control circuit
effectively terminating the charge. For improved battery
lifetime choose 4.0V or 4.1V float voltage.
The battery disconnect function requires some care in se-
lecting the input supply compliance for charging a battery
while powering a load at VCC. The internal battery discon-
nect switch remains off while charging the battery through
the body diode of the internal switch until VCC exceeds
VLBC_VCC. If the source voltage compliance is not greater
than VLBC_VCC, then the battery will never re-connect to
VCC and the system load will not be able to run on battery
power. Users may detect that the battery is connected by
monitoring the NTCBIAS pin as it will periodically pulse
highonceVCChasrisenaboveVLBC_VCC,andstopspulsing
once VCC falls below VLBD.
The simplest application of the LTC4071 is shown in Fig-
ure 2. This application requires only an external resistor
to program the charge/shunt current. Assume the wall
Figure 2. Single-Cell Battery Charger
4071 F02
LTC4071
BAT
RIN = 162, 0.5W
GND
Li-Ion
BATTERY
VCC
+
1F
WALL
ADAPTER
相關PDF資料 |
PDF描述 |
|---|---|
| LTC4071EDDB#TRMPBF | 1-CHANNEL POWER SUPPLY SUPPORT CKT, PDSO8 |
| LTC4071IMS8E#TRPBF | 1-CHANNEL POWER SUPPLY SUPPORT CKT, PDSO8 |
| LTC4071IDDB#TRMPBF | 1-CHANNEL POWER SUPPLY SUPPORT CKT, PDSO8 |
| LTC4071EDDB#TRPBF | 1-CHANNEL POWER SUPPLY SUPPORT CKT, PDSO8 |
| LTC4097EDDB | 2-CHANNEL POWER SUPPLY SUPPORT CKT, PDSO12 |
相關代理商/技術參數(shù) |
參數(shù)描述 |
|---|---|
| LTC4071IDDB | 制造商:LINEAR 制造商全稱:LINEAR 功能描述:Li-Ion/Polymer Shunt Battery Charger System with Low Battery Disconnect |
| LTC4071IDDB#PBF | 制造商:Linear Technology 功能描述:Battery Charger Li-Ion/Li-Polymer 50mA 8-Pin DFN EP |
| LTC4071IDDB#TRPBF | 功能描述:IC LI-ION/POLY BATT CHRGR 8-DFN RoHS:是 類別:集成電路 (IC) >> PMIC - 電池管理 系列:- 標準包裝:61 系列:- 功能:電源管理 電池化學:鋰離子（Li-Ion）、鋰聚合物（Li-Pol） 電源電壓:4.35 V ~ 5.5 V 工作溫度:-40°C ~ 85°C 安裝類型:表面貼裝 封裝/外殼:22-WFDFN 裸露焊盤 供應商設備封裝:22-DFN（6x3）裸露焊盤 包裝:管件 |
| LTC4071IMS8E | 制造商:LINEAR 制造商全稱:LINEAR 功能描述:Li-Ion/Polymer Shunt Battery Charger System with Low Battery Disconnect |
| LTC4071IMS8E#PBF | 功能描述:IC LI-ION/POLY BATT CHRGR 8-MSOP RoHS:是 類別:集成電路 (IC) >> PMIC - 電池管理 系列:- 標準包裝:61 系列:- 功能:電源管理 電池化學:鋰離子（Li-Ion）、鋰聚合物（Li-Pol） 電源電壓:4.35 V ~ 5.5 V 工作溫度:-40°C ~ 85°C 安裝類型:表面貼裝 封裝/外殼:22-WFDFN 裸露焊盤 供應商設備封裝:22-DFN（6x3）裸露焊盤 包裝:管件 |
發(fā)布緊急采購，3分鐘左右您將得到回復。