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參數(shù)資料
| 型號： | LTC4155IUFD#PBF |
| 廠商： | LINEAR TECHNOLOGY CORP |
| 元件分類： | 電源管理 |
| 英文描述： | POWER SUPPLY SUPPORT CKT, PQCC28 |
| 封裝： | 5 X 4 MM, 0.75 MM HEIGHT, PLASTIC, MO-220WXXX-X, QFN-28 |
| 文件頁數(shù)： | 40/52頁 |
| 文件大?。?/td> | 473K |
| 代理商： | LTC4155IUFD#PBF |
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LTC4155
45
4155f
Table 38. Recommended P-Channel Battery Charger MOSFETs
MANUFACTURER
PART
NUMBER
RDS(ON)
(mΩ)
VT (V)
BVDSS (V)
Fairchild
FDMC510P
7.6
–0.5
–20
Vishay
Si7123DN
11.2
–1
–20
Vishay
Si5481DU
2.4
–1
–20
VBUS and VOUT Bypass Capacitors
ThestyleandvalueofthecapacitorsusedwiththeLTC4155
determineseveralimportantparameterssuchasregulator
control loop stability and input voltage ripple. Because
the LTC4155 uses a step-down switching power supply
from VBUS to VOUT, its input current waveform contains
high frequency components. It is strongly recommended
that a low equivalent series resistance (ESR) multilayer
ceramic capacitor be used to bypass VBUS. Tantalum and
aluminum capacitors are not recommended because of
their high ESR. The value of the capacitor on VBUS directly
controlstheamountofinputrippleforagivenloadcurrent.
Increasing the size of this capacitor will reduce the input
ripple. The USB specification allows a maximum of 10μF
to be connected directly across the USB power bus. If the
overvoltage protection circuit is used to protect VBUS,then
its soft-starting nature can be exploited and a larger VBUS
capacitor can be used if desired. If one or both of the input
channels are never used for USB, additional capacitance
placed upstream of the overvoltage protection NMOS de-
vices can absorb significant high frequency current ripple.
To prevent large VOUT voltage steps during transient load
conditions,itisalsorecommendedthataceramiccapacitor
be used to bypass VOUT. The output capacitor is used in
the compensation of the switching regulator. At least 22μF
with low ESR are required on VOUT.Additionalcapacitance
will improve load transient performance and stability.
Multilayer ceramic chip capacitors typically have excep-
tional ESR performance. MLCCs combined with a tight
board layout and an unbroken ground plane will yield very
good performance and low EMI emissions.
The actual in-circuit capacitance of a ceramic capacitor
should be measured with a small AC signal and DC bias,
as is expected in-circuit. Many vendors specify the capaci-
tance versus voltage with a 1VRMS AC test signal and, as
a result, overstate the capacitance that the capacitor will
present in the application. Using similar operating condi-
tionsastheapplication,theusermustmeasure,orrequest
from the vendor, the actual capacitance to determine if the
selected capacitor meets the minimum capacitance that
the application requires.
Programming the Input and Battery Charge
Current Limits
The LTC4155 features independent resistor programma-
bility of the input current limit and battery charge current
limit to facilitate optimal charging from a wide variety of
input power sources. The battery charge current should
be programmed based on the size of the battery and its
associated safe charging rate. Typically this rate is close
to “1C”, or equal to the current which would discharge
the battery in one hour. For example, a 2000mAH battery
would be charged with no more than 2A. With the full-
scale (default) charge current programmed with a resistor
between PROG and GND, all other I2C selectable charge
current settings are lower and may be appropriate for cus-
tom charge algorithms at extreme temperature or battery
voltage. If the battery charge current limit requires more
powerthanisavailablefromtheselectedinputcurrentlimit,
the input current limit will be enforced and the battery will
charge with less than the programmed current. Thus, the
battery charger should be programmed optimally for the
battery without concern for the input source.
Resistive Inputs and Test Equipment
Care must be exercised in the laboratory while evaluating
the LTC4155 with inline ammeters. The combined resis-
tance of the internal current sense resistor and fuse of
many meters can be 0.5Ω or more. At currents of 3A to
4A, it is possible to drop several volts across the meter,
possiblyresultinginunusualvoltagereadingsorartificially
high switch duty cycles.
A resistive connection to the source of input power can
be particularly troublesome. With the undervoltage cur-
rent limit feature enabled, the switching regulator output
power will be automatically reduced to prevent VBUS from
falling below 4.3V. This feature greatly improves tolerance
of resistive input power sources (from either undersized
wiring and connectors or test equipment) and facilitates
APPLICATIONS INFORMATION
相關(guān)PDF資料 |
PDF描述 |
|---|---|
| LTC4215CUFD-2 | 1-CHANNEL POWER SUPPLY SUPPORT CKT, PQCC24 |
| LTC4215IUFD-2#TR | 1-CHANNEL POWER SUPPLY SUPPORT CKT, PQCC24 |
| LTC4215IUFD-2#TRPBF | 1-CHANNEL POWER SUPPLY SUPPORT CKT, PQCC24 |
| LTC4215CUFD-2#TRPBF | 1-CHANNEL POWER SUPPLY SUPPORT CKT, PQCC24 |
| LTC4215IUFD-2 | 1-CHANNEL POWER SUPPLY SUPPORT CKT, PQCC24 |
相關(guān)代理商/技術(shù)參數(shù) |
參數(shù)描述 |
|---|---|
| LTC4156EUFD#PBF | 功能描述:IC POWER LI-ION CHARGER 28-QFN RoHS:是 類別:集成電路 (IC) >> PMIC - 電池管理 系列:* 其它有關(guān)文件:STC3100 View All Specifications 特色產(chǎn)品:STC3100 - Battery Monitor IC 標(biāo)準(zhǔn)包裝:4,000 系列:- 功能:燃料，電量檢測計/監(jiān)控器 電池化學(xué):鋰離子（Li-Ion） 電源電壓:2.7 V ~ 5.5 V 工作溫度:-40°C ~ 85°C 安裝類型:表面貼裝 封裝/外殼:8-TSSOP，8-MSOP（0.118"，3.00mm 寬） 供應(yīng)商設(shè)備封裝:8-MiniSO 包裝:帶卷 (TR) 其它名稱:497-10526-2 |
| LTC4156EUFD#TRPBF | 功能描述:IC POWER LI-ION CHARGER 28-QFN RoHS:是 類別:集成電路 (IC) >> PMIC - 電池管理 系列:* 產(chǎn)品培訓(xùn)模塊:Lead (SnPb) Finish for COTS Obsolescence Mitigation Program 標(biāo)準(zhǔn)包裝:2,500 系列:- 功能:電池監(jiān)控器 電池化學(xué):堿性，鋰離子，鎳鎘，鎳金屬氫化物 電源電壓:1 V ~ 5.5 V 工作溫度:-40°C ~ 85°C 安裝類型:表面貼裝 封裝/外殼:SOT-23-6 供應(yīng)商設(shè)備封裝:SOT-6 包裝:帶卷 (TR) |
| LTC4156IUFD#PBF | 功能描述:IC POWER LI-ION CHARGER 28-QFN RoHS:是 類別:集成電路 (IC) >> PMIC - 電池管理 系列:* 其它有關(guān)文件:STC3100 View All Specifications 特色產(chǎn)品:STC3100 - Battery Monitor IC 標(biāo)準(zhǔn)包裝:4,000 系列:- 功能:燃料，電量檢測計/監(jiān)控器 電池化學(xué):鋰離子（Li-Ion） 電源電壓:2.7 V ~ 5.5 V 工作溫度:-40°C ~ 85°C 安裝類型:表面貼裝 封裝/外殼:8-TSSOP，8-MSOP（0.118"，3.00mm 寬） 供應(yīng)商設(shè)備封裝:8-MiniSO 包裝:帶卷 (TR) 其它名稱:497-10526-2 |
| LTC4156IUFD#TRPBF | 功能描述:IC POWER LI-ION CHARGER 28-QFN RoHS:是 類別:集成電路 (IC) >> PMIC - 電池管理 系列:* 產(chǎn)品培訓(xùn)模塊:Lead (SnPb) Finish for COTS Obsolescence Mitigation Program 標(biāo)準(zhǔn)包裝:2,500 系列:- 功能:電池監(jiān)控器 電池化學(xué):堿性，鋰離子，鎳鎘，鎳金屬氫化物 電源電壓:1 V ~ 5.5 V 工作溫度:-40°C ~ 85°C 安裝類型:表面貼裝 封裝/外殼:SOT-23-6 供應(yīng)商設(shè)備封裝:SOT-6 包裝:帶卷 (TR) |
| LTC4160 | 制造商:LINER 制造商全稱:Linear Technology 功能描述:Switching Power Manager with USB On-The-Go And Overvoltage Protection |
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