- 您现在的位置：买卖IC网 > PDF目录79773 > LTC4065EDC-4.4#TR (LINEAR TECHNOLOGY CORP) 1-CHANNEL POWER SUPPLY SUPPORT CKT, PDSO6 PDF资料下载
参数资料
| 型号： | LTC4065EDC-4.4#TR |
| 厂商： | LINEAR TECHNOLOGY CORP |
| 元件分类： | 电源管理 |
| 英文描述： | 1-CHANNEL POWER SUPPLY SUPPORT CKT, PDSO6 |
| 封装： | 2 X 2 MM, PLASTIC, MO-229WCCD-2, DFN-6 |
| 文件页数： | 4/16页 |
| 文件大小： | 178K |
| 代理商： | LTC4065EDC-4.4#TR |
12
LTC4065-4.4
406544f
Undervoltage Charge Current Limiting (UVCL)
The LTC4065-4.4 includes undervoltage charge (
VUVCL1)
current limiting that prevents full charge current until the
input supply voltage reaches approximately 220mV above
the battery voltage. This feature is particularly useful if the
LTC4065-4.4 is powered from a supply with long leads (or
any relatively high output impedance).
For example, USB-powered systems tend to have highly
variable source impedances (due primarily to cable quality
and length). A transient load combined with such imped-
ance can easily trip the UVLO threshold and turn the
charger off unless undervoltage charge current limiting is
implemented.
Consider a situation where the LTC4065-4.4 is operating
under normal conditions and the input supply voltage
begins to droop (e.g., an external load drags the input
supply down). If the input voltage reaches VBAT + VUVCL1
(approximately 220mV above the battery voltage),
undervoltage charge current limiting will begin to reduce
the charge current in an attempt to maintain
VUVCL1
between the VCC input and the BAT output of the IC. The
LTC4065-4.4 will continue to operate at the reduced
charge current until the input supply voltage is increased
or voltage mode reduces the charge current further.
Operation from Current Limited Wall Adapter
By using a current limited wall adapter as the input
supply, the LTC4065-4.4 dissipates significantly less
power when programmed for a current higher than the
limit of the supply as compared to using a noncurrent
limited supply at the same charge current.
Consider a situation where an application demands a
600mA charge current for an 800mAh Li-Ion battery. If a
typical 5V (noncurrent limited) input supply is available
then the peak power dissipation inside the part can
exceed 1W.
Now consider the same scenario, but with a 5V input
supply with a 600mA current limit. To take advantage of
the supply, it is necessary to program the LTC4065-4.4 to
charge at a current above 600mA. Assume that the
LTC4065-4.4 is programmed for 750mA (i.e., RPROG =
1.33k) to ensure that part tolerances maintain a pro-
grammed current higher than 600mA. Since the LTC4065-
4.4 will demand a charge current higher than the current
limit of the input supply, the supply voltage will drop to the
battery voltage plus 600mA times the on-resistance of the
internal PFET. The on-resistance of the LTC4065-4.4 power
device is approximately 450m
with a 5V supply. The
actual on-resistance will be slightly higher due to the fact
that the input supply will drop to less than 5V. The power
dissipated during this phase of charging is less than
180mW. That is an 82% improvement over the noncurrent
limited supply power dissipation.
USB and Wall Adapter Power
Although the LTC4065-4.4 allow charging from a USB
port, a wall adapter can also be used to charge Li-Ion
batteries. Figure 3 shows an example of how to combine
wall adapter and USB power inputs. A P-channel MOSFET,
MP1, is used to prevent back conducting into the USB port
when a wall adapter is present and Schottky diode, D1, is
used to prevent USB power loss through the 1k pull-down
resistor.
Typically a wall adapter can supply significantly more
current than the 500mA-limited USB port. Therefore, an
N-channel MOSFET, MN1, and an extra program resistor
are used to increase the charge current to 750mA when the
wall adapter is present.
Figure 3. Combining Wall Adapter and USB Power
VCC
MP1
MN1
1k
2k
4.02k
3
ICHG
4
6
Li-Ion
BATTERY
SYSTEM
LOAD
4065 F03
LTC4065-4.4
BAT
USB
POWER
500mA
ICHG
5V WALL
ADAPTER
750mA
ICHG
PROG
+
D1
APPLICATIO S I FOR ATIO
WU
UU
相关PDF资料 |
PDF描述 |
|---|---|
| LS4501-7ERDDTB1 | 1-OUTPUT 100 W AC-DC PWR FACTOR CORR MODULE |
| LS4001-7EPD8B2 | 1-OUTPUT 100 W AC-DC PWR FACTOR CORR MODULE |
| LS4001-7EPD8TB2 | 1-OUTPUT 100 W AC-DC PWR FACTOR CORR MODULE |
| LS4001-7PD0TB2 | 1-OUTPUT 100 W AC-DC PWR FACTOR CORR MODULE |
| LS4001-7PD6B2 | 1-OUTPUT 100 W AC-DC PWR FACTOR CORR MODULE |
相关代理商/技术参数 |
参数描述 |
|---|---|
| LTC4065L | 制造商:LINEAR 制造商全称:LINEAR 功能描述:Standalone 250mA Li-Ion Battery Charger in 2 × 2 DFN |
| LTC4065L_12 | 制造商:LINEAR 制造商全称:LINEAR 功能描述:Standalone 250mA Li-Ion Battery Charger in 2 × 2 DFN |
| LTC4065LEDC#TRM | 制造商:Linear Technology 功能描述:BATT CHARGER LI ON 250MA 6DFN |
| LTC4065LEDC#TRMPBF | 功能描述:IC CHARGER LI-ION 6-DFN RoHS:是 类别:集成电路 (IC) >> PMIC - 电池管理 系列:- 其它有关文件:STC3100 View All Specifications 特色产品:STC3100 - Battery Monitor IC 标准包装:4,000 系列:- 功能:燃料，电量检测计/监控器 电池化学:锂离子（Li-Ion） 电源电压:2.7 V ~ 5.5 V 工作温度:-40°C ~ 85°C 安装类型:表面贴装 封装/外壳:8-TSSOP，8-MSOP（0.118"，3.00mm 宽） 供应商设备封装:8-MiniSO 包装:带卷 (TR) 其它名称:497-10526-2 |
| LTC4065LEDC#TRPBF | 功能描述:IC CHARGER LI-ION 6-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 |
发布紧急采购，3分钟左右您将得到回复。