參數(shù)資料
型號: LTC4097EDDB
廠商: LINEAR TECHNOLOGY CORP
元件分類: 電源管理
英文描述: 2-CHANNEL POWER SUPPLY SUPPORT CKT, PDSO12
封裝: 3 X 2 MM, 0.75 MM HEIGHT, PLASTIC, DFN-12
文件頁數(shù): 8/20頁
文件大?。?/td> 219K
代理商: LTC4097EDDB
LTC4097
16
4097f
APPLICATIONS INFORMATION
The LTC4097 can be used above 64°C ambient, but the
charge current will be reduced from 500mA. The ap-
proximate current at a given ambient temperature can be
approximated by:
I
CT
VV
BAT
A
IN
BAT
JA
=
°
115
(–
) θ
Using the previous example with an ambient temperature
of 75°C, the charge current will be reduced to approxi-
mately:
I
CC
VV
C W
C
CA
BAT =
°°
°
=
°
115
75
53 3
60
40
102
(– .
)
/
IImA
BAT = 392
It is important to remember that LTC4097 applications do
not need to be designed for worst-case thermal conditions,
since the IC will automatically reduce power dissipation
when the junction temperature reaches approximately
115°C. Moreover a thermal shut down protection circuit
around 150°C safely prevents any damage by forcing the
LTC4097 into shut down mode.
Thermal Considerations
In order to deliver maximum charge current under all
conditions, it is critical that the exposed metal pad on the
backside of the LTC4097 package is properly soldered
to the PC board ground. When correctly soldered to a
2500mm2 double sided 1oz copper board, the LTC4097
has a thermal resistance of approximately 60°C/W. Failure
to make thermal contact between the exposed pad on the
backside of the package and the copper board will result in
thermal resistances far greater than 60°C/W. As an example,
a correctly soldered LTC4097 can deliver over 500mA to
a battery from a 5V supply at room temperature. Without
a good backside thermal connection, this number would
drop to much less than 300mA.
Alternate NTC Thermistors and Biasing
The LTC4097 provides temperature qualied charging if
a grounded thermistor and a bias resistor are connected
to NTC. By using a bias resistor whose value is equal to
the room temperature resistance of the thermistor (R25)
the upper and lower temperatures are pre-programmed
to approximately 40°C and 0°C, respectively (assuming
a Vishay “Curve 1” thermistor).
The upper and lower temperature thresholds can be ad-
justed by either a modication of the bias resistor value
or by adding a second adjustment resistor to the circuit.
If only the bias resistor is adjusted, then either the upper
or the lower threshold can be modied but not both. The
other trip point will be determined by the characteristics
of the thermistor. Using the bias resistor in addition to an
adjustment resistor, both the upper and the lower tempera-
ture trip points can be independently programmed with
the constraint that the difference between the upper and
lower temperature thresholds cannot decrease. Examples
of each technique are given below.
NTC thermistors have temperature characteristics which
are indicated on resistance-temperature conversion tables.
The Vishay-Dale thermistor NTHS0603N011-N1003F, used
in the following examples, has a nominal value of 100k
and follows the Vishay “Curve 1” resistance-temperature
characteristic.
In the explanation below, the following notation is used.
R25 = Value of the Thermistor at 25°C
RNTC|COLD = Value of thermistor at the cold trip point
RNTC|HOT = Value of the thermistor at the hot trip
point
rCOLD = Ratio of RNTC|COLD to R25
rHOT= Ratio of RNTC|HOT to R25
RNOM = Primary thermistor bias resistor (see Fig-
ure 4)
R1 = Optional temperature range adjustment resistor
(see Figure 5)
The trip points for the LTC4097’s temperature qualication
are internally programmed at 0.349 VNTC for the hot
threshold and 0.765 VNTC for the cold threshold.
Therefore, the hot trip point is set when:
R
RR
VNTC
NTC HOT
NOM
NTC HOT
|
.
+
= 0 349
相關(guān)PDF資料
PDF描述
LTC4098EUDC-1#TRPBF BATTERY CHARGE CONTROLLER, 2650 kHz SWITCHING FREQ-MAX, PQCC20
LTC4098EPDC-1#PBF BATTERY CHARGE CONTROLLER, 2650 kHz SWITCHING FREQ-MAX, PQCC20
LTC4098EUDC-1#PBF BATTERY CHARGE CONTROLLER, 2650 kHz SWITCHING FREQ-MAX, PQCC20
LTC4110EUHF#TR 1-CHANNEL POWER SUPPLY SUPPORT CKT, PQCC38
LTC4110EUHF 1-CHANNEL POWER SUPPLY SUPPORT CKT, PQCC38
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
LTC4097EDDB#PBF 制造商:Linear Technology 功能描述:Battery Charger Li-Ion/Li-Pol 1200mA 4.2V 12-Pin DFN EP
LTC4097EDDB#TRMPBF 功能描述:IC CHARGER LI-ION/POLY 12-DFN RoHS:是 類別:集成電路 (IC) >> PMIC - 電池管理 系列:- 標準包裝:2,000 系列:Impedance Track™ 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:2.4 V ~ 2.6 V 工作溫度:-40°C ~ 85°C 安裝類型:表面貼裝 封裝/外殼:20-TSSOP(0.173",4.40mm 寬) 供應(yīng)商設(shè)備封裝:20-TSSOP 包裝:帶卷 (TR) 產(chǎn)品目錄頁面:1020 (CN2011-ZH PDF) 配用:BQ27350EVM-ND - BQ27350EVM 其它名稱:296-21665-2
LTC4097EDDB#TRPBF 功能描述:IC CHARGER LI-ION/POLY 12-DFN RoHS:是 類別:集成電路 (IC) >> PMIC - 電池管理 系列:- 標準包裝: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
LTC4098 制造商:LINER 制造商全稱:Linear Technology 功能描述:Dual-Input Power Manager
LTC4098-1 制造商:LINER 制造商全稱:Linear Technology 功能描述:Dual-Input Power Manager