- 您现在的位置：买卖IC网 > PDF目录1834 > LTC4078EDD-2#TRPBF (Linear Technology)IC USB POWER MANAGER 10-DFN PDF资料下载
参数资料
| 型号： | LTC4078EDD-2#TRPBF |
| 厂商： | Linear Technology |
| 文件页数： | 12/16页 |
| 文件大小： | 0K |
| 描述： | IC USB POWER MANAGER 10-DFN |
| 标准包装： | 2,500 |
| 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： | 4.3 V ~ 5.5 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) |
LTC4078/LTC4078X
APPLICATIONS INFORMATION
Using a Single Charge Current Program Resistor
The LTC4078/LTC4078X can program the wall adapter
charge current and USB charge current independently using
two program resistors, R IDC and R IUSB . Figure 2 shows a
charger circuit that sets the wall adapter charge current
to 800mA and the USB charge current to 500mA.
In applications where the programmed wall adapter
charge current and USB charge current are the same, a
single program resistor can be used to set both charge
currents. Figure 3 shows a charger circuit that uses one
charge current program resistor.
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 1Ω 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 or IUSB) is in the feedback loop,
not the battery. The constant-current mode stability is af-
fected by the impedance at the charge current program pin.
With no additional capacitance on this pin, the charger is
WALL
LTC4078
800mA (WALL)
500mA (USB)
stable with program resistor values as high as 20k (I CHRG
= 50mA); however, additional capacitance on these nodes
ADAPTER
DCIN
BAT
reduces the maximum allowed program resistor.
+
USB
PORT
C1
1 μ F
C2, 1 μ F
R1
2k
1%
R2
1.24k
1%
USBIN BATDET
IUSB
IDC ITERM
GND
R3
2k
1%
R4
3.9k
4.2V
Li-Ion
BATTERY
PACK
Power Dissipation
When designing the battery charger circuit, it is not
necessary to design for worst-case power dissipation
scenarios because the LTC4078/LTC4078X automatically
4078X F02
Figure 2. Dual Input Charger with Independent Charge Currents
reduce the charge current during high power conditions.
The conditions that cause the LTC4078/LTC4078X to
reduce charge current through thermal feedback can be
+
WALL
ADAPTER
USB
PORT
C1
1 μ F
C2, 1 μ F
R1
2k
1%
LTC4078
DCIN BAT
USBIN BATDET
IUSB
IDC ITERM
GND
R3
2k
1%
500mA
R4
3.9k
4.2V
Li-Ion
BATTERY
PACK
approximated by considering the power dissipated in the
IC. Most of the power dissipation is generated from the
internal charger MOSFET. Thus, the power dissipation is
calculated to be:
P D = (V IN – V BAT ) ? I BAT
P D is the dissipated power, V IN is the input supply volt-
4078X F03
Figure 3. Dual Input Charger Circuit. The Wall Adapter
Charge Current and USB Charge Current Are Both
Programmed to Be 500mA
In this circuit, the programmed charge current from both the
wall adapter supply is the same value as the programmed
charge current from the USB supply:
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:
T A = 120°C – P D ? θ JA
T A = 120°C – (V IN – V BAT ) ? I BAT ? θ JA
Example: An LTC4078/LTC4078X operating from a 5V wall
I CHRG
DC = I CHRG USB =
1000V
R ISET
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.
4078xfb
12
相关PDF资料 |
PDF描述 |
|---|---|
| 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 |
| LTC4089EDJC-5#TRPBF | IC USB POWER MANAGER 22-DFN |
相关代理商/技术参数 |
参数描述 |
|---|---|
| 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 |
| LTC4078XEDD#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 |
| LTC4078XEDD#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 |
| LTC4078XEDD-PBF | 制造商:LINER 制造商全称:Linear Technology 功能描述:Dual Input Li-Ion Battery Charger with Overvoltage Protection |
| LTC4078XEDD-TRPBF | 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。