參數(shù)資料
型號(hào): LTC4054L-4.2
廠商: Linear Technology Corporation
英文描述: 150mA Standalone Linear Li-Ion Battery Charger in ThinSOT
中文描述: 150mA的獨(dú)立線性鋰離子電池充電器采用ThinSOT
文件頁數(shù): 13/16頁
文件大小: 191K
代理商: LTC4054L-4.2
13
LTC4054L-4.2
4054l42f
APPLICATIOU
V
CC
Bypass Capacitor
Many types of capacitors can be used for input bypassing,
however, caution must be exercised when using multi-
layer ceramic capacitors. Because of the self resonant and
high Q characteristics of some types of ceramic capaci-
tors, high voltage transients can be generated under some
start-up conditions, such as connecting the charger input
to a live power source. Adding a 1.5
resistor in series
with an X5R ceramic capacitor will minimize start-up
voltage transients. For more information, refer to Applica-
tion Note 88.
W
U
U
CHRG
OUT
IN
2k
800k
4054L42 F03
LTC4054L
μ
PROCESSOR
V
+
V
DD
V
CC
Figure 3. Using a Microprocessor to Determine CHRG State
Charge Current Soft-Start
The LTC4054L includes a soft-start circuit to minimize the
inrush current at the start of a charge cycle. When a charge
cycle is initiated, the charge current ramps from zero to the
full-scale current over a period of approximately 100
μ
s.
This has the effect of minimizing the transient current load
on the power supply during start-up.
CHRG Status Output Pin
The CHRG pin can provide an indication that the input
voltage is greater than the undervoltage lockout thresh-
old level. A weak pull-down current of approximately
20
μ
A indicates that sufficient voltage is applied to V
CC
to
begin charging. When a discharged battery is connected
to the charger, the constant current portion of the charge
cycle begins and the CHRG pin pulls to ground. The
CHRG pin can sink up to 10mA to drive an LED that
indicates that a charge cycle is in progress.
When the battery is nearing full charge, the charger enters
the constant-voltage portion of the charge cycle and the
charge current begins to drop. When the charge current
drops below 1/10 of the programmed current, the charge
cycle ends, and the strong pull-down is replaced by the
20
μ
A pull-down, indicating that the charge cycle has
ended. If the input voltage is removed or drops below the
undervoltage lockout threshold, the CHRG pin becomes
high impedance. Figure 3 shows that by using two differ-
ent value pull-up resistors, a microprocessor can detect all
three states from this pin.
To detect when the LTC4054L is in charge mode, force the
digital output pin (OUT) high and measure the voltage at
the CHRG pin. The N-channel MOSFET will pull the pin
voltage low even with the 2k pull-up resistor. Once the
charge cycle terminates, the N-channel MOSFET is turned
off and a 20
μ
A current source is connected to the CHRG
pin. The IN pin will then be pulled high by the 2k pull-up
resistor. To determine if there is a weak pull-down current,
the OUT pin should be forced to a high impedance state.
The weak current source will pull the IN pin low through
the 800k resistor; if CHRG is high impedance, the IN pin
will be pulled high, indicating that the part is in a UVLO
state.
相關(guān)PDF資料
PDF描述
LTC4054LES5-4.2 150mA Standalone Linear Li-Ion Battery Charger in ThinSOT
LTC4054 Standalone Linear Li-lon Battery Charger with Thermistor Input
LTC1731 150mA Standalone Linear Li-Ion Battery Charger in ThinSOT
LTC1732 150mA Standalone Linear Li-Ion Battery Charger in ThinSOT
LTC1732-8.4 Lithium-Ion Linear Battery Charger Controller
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
LTC4054LES5-4.2 制造商:Linear Technology 功能描述:Battery Charger Li-Ion 10mA to 150mA 4.2V 5-Pin TSOT-23
LTC4054LES5-4.2#PBF 制造商:Linear Technology 功能描述:Bulk 制造商:Linear Technology 功能描述:CHARGER BATTERY LI-ION 0.8A 5SOT23 制造商:Linear Technology 功能描述:CHARGER, BATTERY, LI-ION, 0.8A, 5SOT23
LTC4054LES5-4.2#TR 功能描述:IC CHARGR BATTERY L-ION TSOT23-5 RoHS:否 類別:集成電路 (IC) >> PMIC - 電池管理 系列:- 標(biāo)準(zhǔn)包裝:61 系列:- 功能:電源管理 電池化學(xué):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(yīng)商設(shè)備封裝:22-DFN(6x3)裸露焊盤 包裝:管件
LTC4054LES5-4.2#TRM 功能描述:IC CHARGR BATTERY L-ION TSOT23-5 RoHS:否 類別:集成電路 (IC) >> PMIC - 電池管理 系列:- 標(biāo)準(zhǔn)包裝:61 系列:- 功能:電源管理 電池化學(xué):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(yīng)商設(shè)備封裝:22-DFN(6x3)裸露焊盤 包裝:管件
LTC4054LES5-4.2#TRMPBF 功能描述:IC CHAR BATTERY L-ION TSOT23-5 RoHS:是 類別:集成電路 (IC) >> PMIC - 電池管理 系列:- 標(biāo)準(zhǔn)包裝:1 系列:- 功能:充電管理 電池化學(xué):鋰離子(Li-Ion)、鋰聚合物(Li-Pol) 電源電壓:3.75 V ~ 6 V 工作溫度:-40°C ~ 85°C 安裝類型:表面貼裝 封裝/外殼:SC-74A,SOT-753 供應(yīng)商設(shè)備封裝:SOT-23-5 包裝:剪切帶 (CT) 產(chǎn)品目錄頁面:669 (CN2011-ZH PDF) 其它名稱:MCP73831T-2ACI/OTCT