- 您现在的位置：买卖IC网 > PDF目录1834 > LTC4077EDD#TRPBF (Linear Technology)IC CHARG BATT LI-ON USB 10DFN PDF资料下载
参数资料
| 型号： | LTC4077EDD#TRPBF |
| 厂商： | Linear Technology |
| 文件页数： | 13/16页 |
| 文件大小： | 0K |
| 描述： | IC CHARG BATT LI-ON USB 10DFN |
| 标准包装： | 2,500 |
| 功能： | 充电管理 |
| 电池化学： | 锂离子（Li-Ion） |
| 电源电压： | 4.3 V ~ 8 V |
| 工作温度： | -40°C ~ 85°C |
| 安装类型： | 表面贴装 |
| 封装/外壳： | 10-WFDFN 裸露焊盘 |
| 供应商设备封装： | 10-DFN（3x3） |
| 包装： | 带卷 (TR) |
LTC4077
APPLICATIO S I FOR ATIO
I BAT =
I BAT =
105 ° C ± 60 ° C 45 ° C
Stability Considerations
The constant-voltage mode feedback loop is stable without
any compensation provided a battery is connected to the
charger output. However, a 1μF capacitor with a 1 Ω series
resistor is recommended at the BAT pin to keep the ripple
voltage low when the battery is disconnected.
When the charger is in constant-current mode, the charge
current program pin (IDC, IUSB or IUSBL) is in the feed-
back loop, not the battery. The constant-current mode
stability is affected by the impedance at the charge current
program pin. With no additional capacitance on this pin,
the charger is stable with program resistor values as high
as 20k; however, additional capacitance on these nodes
reduces the maximum allowed program resistor.
Power Dissipation
When designing the battery charger circuit, it is not neces-
sary to design for worst-case power dissipation scenarios
because the LTC4077 automatically reduces the charge
current during high power conditions. The conditions
that cause the LTC4077 to reduce charge current through
thermal feedback can be approximated by considering the
power dissipated in the IC. Most of the power dissipation
is generated from the internal MOSFET pass device, thus,
the power dissipation is calculated to be:
P D = (V IN – V BAT ) ? I BAT
P D is the power dissipated, V IN is the input supply volt-
age (either DCIN or USBIN), V BAT is the battery voltage
and I BAT is the charge current. The approximate ambient
temperature at which the thermal feedback begins to
protect the IC is:
Example: An LTC4077 operating from a 5V wall adapter (on
the DCIN input) is programmed to supply 800mA full-scale
current to a discharged Li-Ion battery with a voltage of 3.3V.
Assuming θ JA is 40°C/W (see Thermal Considerations),
the ambient temperature at which the LTC4077 will begin
to reduce the charge current is approximately:
T A = 105°C – (5V – 3.3V) ? (800mA) ? 40°C/W
T A = 105°C – 1.36W ? 40°C/W = 105°C – 54.4°C
T A = 50.6°C
The LTC4077 can be used above 50.6°C ambient, but
the charge current will be reduced from 800mA. The ap-
proximate current at a given ambient temperature can be
approximated by:
105 ° C ± T A
( V IN ± V BAT ) ? Q JA
Using the previous example with an ambient tem-
perature of 60°C, the charge current will be reduced to
approximately:
=
( 5 V ± 3 . 3 V ) ? 40 ° C / W 68 ° C / A
I BAT = 662 MA
It is important to remember that LTC4077 applications do
not need to be designed for worst-case thermal conditions,
since the IC will automatically reduce power dissipation
when the junction temperature reaches approximately
105°C.
T A = 105°C – P D ? θ JA
T A = 105°C – (V IN – V BAT ) ? I BAT ? θ JA
4077fa
13
相关PDF资料 |
PDF描述 |
|---|---|
| LTC4078EDD-2#TRPBF | IC USB POWER MANAGER 10-DFN |
| LTC4080EMSE#TRPBF | IC CHARGER LI-ION 10-MSOP |
| LTC4081EDD#TRPBF | IC USB POWER MANAGER 10-DFN |
| LTC4085EDE#TRPBF | IC USB POWER MANAGER 14-DFN |
| LTC4088EDE#TRPBF | IC BATT CHARGER/USB 14-DFN |
相关代理商/技术参数 |
参数描述 |
|---|---|
| LTC4078EDD#PBF | 功能描述:IC USB POWER MANAGER 12-DFN 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 |
| LTC4078EDD#TRPBF | 功能描述:IC USB POWER MANAGER 12-DFN 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 |
| LTC4078EDD-2#PBF | 功能描述:IC USB POWER MANAGER 10-DFN 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 |
| LTC4078EDD-2#TRPBF | 功能描述:IC USB POWER MANAGER 10-DFN 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 |
| LTC4078X | 制造商:LINER 制造商全称:Linear Technology 功能描述:Dual Input Li-Ion Battery Charger with Overvoltage Protection |
发布紧急采购，3分钟左右您将得到回复。