参数资料
| 型号： | LTC4081EDD#TRPBF |
| 厂商： | Linear Technology |
| 文件页数： | 11/24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： | 3.75 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) |
LTC4081
OPERATIO
The LTC4081 is a full-featured linear battery charger with
an integrated synchronous buck converter designed pri-
marily for handheld applications. The battery charger is
capable of charging single-cell 4.2V Li-Ion batteries. The
buck converter is powered from the BAT pin and has a
programmable output voltage providing a maximum load
current of 300mA. The converter and the battery charger
can run simultaneously or independently of each other.
BATTERY CHARGER OPERATION
Featuring an internal P-channel power MOSFET, MP1,
the battery charger uses a constant-current/constant-
voltage charge algorithm with programmable current.
Charge current can be programmed up to 500mA with a
?nal ?oat voltage of 4.2V ±0.5%. The ? C ? H ? R ? G open-drain
status output indicates when C/10 has been reached. No
blocking diode or external sense resistor is required; thus,
the basic charger circuit requires only two external com-
ponents. An internal charge termination timer adheres to
battery manufacturer safety guidelines. Furthermore, the
LTC4081 battery charger is capable of operating from a
USB power source.
A charge cycle begins when the voltage at the V CC pin
rises above 3.6V and approximately 82mV above the BAT
pin voltage, a 1% program resistor is connected from the
PROG pin to ground, and the ? E ? N ? _ ? C ? H ? R ? G pin is pulled below
the shutdown threshold (V IL ).
When the BAT pin approaches the ?nal ?oat voltage of
4.2V, the battery charger enters constant-voltage mode
and the charge current begins to decrease. When the
current drops to 10% of the full-scale charge current, an
internal comparator turns off the N-channel MOSFET driving
the ? C ? H ? R ? G pin, and the pin becomes high impedance.
An internal thermal limit reduces the programmed charge
current if the die temperature attempts to rise above a
preset value of approximately 115°C. This feature protects
the LTC4081 from excessive temperature and allows the
user to push the limits of the power handling capability
of a given circuit board without the risk of damaging the
LTC4081 or external components. Another bene?t of the
thermal limit is that charge current can be set according
to typical, rather than worst-case, ambient temperatures
for a given application with the assurance that the battery
charger will automatically reduce the current in worst-case
conditions.
An internal timer sets the total charge time, t TIMER (typi-
cally 4.5 hours). When this time elapses, the charge cycle
terminates and the ? C ? H ? R ? G pin assumes a high impedance
state even if C/10 has not yet been reached. To restart
the charge cycle, remove the input voltage and reapply
it or momentarily force the ? E ? N ? _ ? C ? H ? R ? G pin above V IH . A
new charge cycle will automatically restart if the BAT pin
voltage falls below V RECHRG (typically 4.1V).
Constant-Current / Constant-Voltage /
Constant-Temperature
The LTC4081 battery charger uses a unique architecture
to charge a battery in a constant-current, constant-volt-
age and constant-temperature fashion. Figure 1 shows a
Simpli?ed Block Diagram of the LTC4081. Three of the
ampli?er feedback loops shown control the constant-cur-
rent, CA, constant-voltage, VA, and constant-temperature,
TA modes. A fourth ampli?er feedback loop, MA, is used to
increase the output impedance of the current source pair,
MP1 and MP3 (note that MP1 is the internal P-channel
power MOSFET). It ensures that the drain current of MP1
is exactly 400 times the drain current of MP3.
Ampli?ers CA and VA are used in separate feedback loops
to force the charger into constant-current or constant-
voltage mode, respectively. Diodes D1 and D2 provide
priority to either the constant-current or constant-voltage
loop, whichever is trying to reduce the charge current the
most. The output of the other ampli?er saturates low which
effectively removes its loop from the system. When in
constant-current mode, CA servos the voltage at the PROG
pin to be precisely 1V. VA servos its non-inverting input
to 1.22V when in constant-voltage mode and the internal
resistor divider made up of R1 and R2 ensures that the
battery voltage is maintained at 4.2V. The PROG pin volt-
age gives an indication of the charge current anytime in
the charge cycle, as discussed in “Programming Charge
Current” in the Applications Information section.
4081f
11
相关PDF资料 |
PDF描述 |
|---|---|
| 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 |
| LTC4090EDJC-5#TRPBF | IC USB POWER MANAGER 22-DFN |
| LTC4095EDC#TRPBF | IC CHARGER LI-ION/POLY 8-DFN |
相关代理商/技术参数 |
参数描述 |
|---|---|
| LTC4085 | 制造商:LINER 制造商全称:Linear Technology 功能描述:High Efficiency Battery Charger/USB Power Manager |
| LTC4085-1 | 制造商:LINER 制造商全称:Linear Technology 功能描述:USB Power Manager with Ideal Diode Controller and 4.1V Li-Ion Charger |
| LTC4085-3 | 制造商:LINER 制造商全称:Linear Technology 功能描述:USB Power Manager with Ideal Diode Controller and 3.95V Li-Ion Charger |
| LTC4085EDE | 制造商:Linear Technology 功能描述:USB Power Manager 14-Pin DFN EP |
| LTC4085EDE#PBF | 功能描述:IC USB POWER MANAGER 14-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 |
发布紧急采购，3分钟左右您将得到回复。