- 您現在的位置：買賣IC網 > PDF目錄377749 > LTC1473L (Linear Technology Corporation) Dual General Purpose LinCMOS(TM) Differential Comparator 8-SOIC -40 to 125 PDF資料下載
參數資料
| 型號： | LTC1473L |
| 廠商： | Linear Technology Corporation |
| 英文描述： | Dual General Purpose LinCMOS(TM) Differential Comparator 8-SOIC -40 to 125 |
| 中文描述： | 雙低電壓PowerPathTM開關驅動器 |
| 文件頁數： | 10/16頁 |
| 文件大?。?/td> | 211K |
| 代理商： | LTC1473L |
LTC 1473L
10
power dissipated in the switches is never allowed to rise
above the manufacturers’ recommended level.
Inrush Current Sense Resistor, R
SENSE
A small valued sense resistor (current shunt) is used by
the two switch pair drivers to measure and limit the inrush
or short-circuit current flowing through the conducting
switch pair.
The inrush current limit should be set at approximately 2
×
or 3
×
the maximum required output current. For example,
if the maximum current required by the DC/DC converter
is 2A, an inrush current limit of 6A is set by selecting a
0.033
sense resistor, R
SENSE
, using the following
formula:
R
SENSE
= (200mV)/I
INRUSH
Note that the voltage drop across the resistor in this
example is only 66mV under normal operating conditions.
Therefore, the power dissipated in the resistor is ex-
tremely small (132mW), and a small 1/4W surface mount
resistor can be used in this application (the resistor will
tolerate the higher power dissipation during current limit
for the duration of the fault time-out). A number of small
valued surface mount resistors are available that have
been specifically designed for high efficiency current
sensing applications.
Programmable Fault Timer Capacitor, C
TIMER
A fault timer capacitor, C
TIMER
, is used to program the time
duration the MOSFET switches are allowed to be in current
limit continuously. This feature can be disabled by either
grounding the TIMER pin or asserting DIODE low and
asserting either IN1 or IN2 high.
In the event of a fault condition, the MOSFET switch is
driven into current limit by the inrush current limit loop.
The MOSFET switch operating in current limit is in a high
dissipation mode and can fail catastrophically if not
promptly terminated.
The fault time delay is programmed with an external
capacitor connected between the TIMER pin and GND. At
the instant the MOSFET switch enters current limit, a 6
μ
A
current source starts charging C
TIMER
through the TIMER
pin. When the voltage across C
TIMER
reaches 1.16V an
internal latch is set and the MOSFET switch is turned off.
To reset the latch, the logic input of the MOSFET gate
driver must be deselected.
The fault time delay should be programmed as large as
possible, at least 3
×
to 5
×
the maximum switching transi-
tion period, to avoid prematurely tripping the protection
circuit. Conversely, for the protection circuit to be effec-
tive, the fault time delay must be within the safe operating
area of the MOSFET switches as stated in the manufacturer’s
data sheet.
The maximum switching transition period happens during
a cold start, when a fully charged battery is connected to
an unpowered system. The inrush current charging up the
system supply capacitor to the battery voltage determines
the switching transition period.
The following example illustrates the calculation of C
TIMER.
Assume the maximum battery voltage is 10V, the system
supply capacitor is 100
μ
F, the inrush current limit is 6A
and the maximum current required by the following sys-
tem is 2A. Then, the maximum switching transition period
is calculated using the following formula:
)
(
t
V
C
I
I
t
F
A
A
s
SW MAX
(
BAT MAX
(
INSYSTEM
INRUSH
μ
2
LOAD
SW MAX
(
)
)
)
=
(
)
=
( )
(
)
=
μ
)
6
250
Multiplying 3 by 250
μ
s gives 0.75ms, the minimum fault
delay time. Make sure this delay time does not fall outside
of the safe operating area of the MOSFET switch dissipat-
ing 30W (6A 10V/2). Using this delay time the C
TIMER
can
be calculated using the following formula:
C
ms
A
V
pF
ITMER
=
μ
=
075
.
6
.
116
3879
Therefore, C
TIMER
can be 3900pF.
APPLICATIO S U
U
W
U
相關PDF資料 |
PDF描述 |
|---|---|
| LTC1475CMS8 | Low-Power LinCMOS(TM) Dual Comparator 20-LCCC -55 to 125 |
| LTC1474CMS8 | Low Quiescent Current High Efficiency Step-Down Converters |
| LTC1474CMS8-3.3 | Low Quiescent Current High Efficiency Step-Down Converters |
| LTC1474CMS8-5 | Low Quiescent Current High Efficiency Step-Down Converters |
| LTC1474CS8 | Low Quiescent Current High Efficiency Step-Down Converters |
相關代理商/技術參數 |
參數描述 |
|---|---|
| LTC1473LCGN | 功能描述:IC SWITCH DVR PWRPATH DUAL16SSOP RoHS:否 類別:集成電路 (IC) >> PMIC - O 圈控制器 系列:PowerPath™ 標準包裝:1,000 系列:- 應用:電池備份，工業(yè)/汽車，大電流開關 FET 型:- 輸出數:5 內部開關:是 延遲時間 - 開啟:100ns 延遲時間 - 關閉:- 電源電壓:3 V ~ 5.5 V 電流 - 電源:250µA 工作溫度:0°C ~ 70°C 安裝類型:表面貼裝 封裝/外殼:16-SOIC（0.154"，3.90mm 寬） 供應商設備封裝:16-SOIC N 包裝:帶卷 (TR) |
| LTC1473LCGN#PBF | 功能描述:IC SWITCH DVR PWRPATH DUAL16SSOP RoHS:是 類別:集成電路 (IC) >> PMIC - O 圈控制器 系列:PowerPath™ 標準包裝:1,000 系列:- 應用:電池備份，工業(yè)/汽車，大電流開關 FET 型:- 輸出數:5 內部開關:是 延遲時間 - 開啟:100ns 延遲時間 - 關閉:- 電源電壓:3 V ~ 5.5 V 電流 - 電源:250µA 工作溫度:0°C ~ 70°C 安裝類型:表面貼裝 封裝/外殼:16-SOIC（0.154"，3.90mm 寬） 供應商設備封裝:16-SOIC N 包裝:帶卷 (TR) |
| LTC1473LCGN#TR | 功能描述:IC DRIVER SWITCH DUAL LV 16SSOP RoHS:否 類別:集成電路 (IC) >> PMIC - O 圈控制器 系列:PowerPath™ 標準包裝:1,000 系列:- 應用:電池備份，工業(yè)/汽車，大電流開關 FET 型:- 輸出數:5 內部開關:是 延遲時間 - 開啟:100ns 延遲時間 - 關閉:- 電源電壓:3 V ~ 5.5 V 電流 - 電源:250µA 工作溫度:0°C ~ 70°C 安裝類型:表面貼裝 封裝/外殼:16-SOIC（0.154"，3.90mm 寬） 供應商設備封裝:16-SOIC N 包裝:帶卷 (TR) |
| LTC1473LCGN#TRPBF | 功能描述:IC SWITCH DVR PWRPATH DUAL16SSOP RoHS:是 類別:集成電路 (IC) >> PMIC - O 圈控制器 系列:PowerPath™ 標準包裝:1,000 系列:- 應用:電池備份，工業(yè)/汽車，大電流開關 FET 型:- 輸出數:5 內部開關:是 延遲時間 - 開啟:100ns 延遲時間 - 關閉:- 電源電壓:3 V ~ 5.5 V 電流 - 電源:250µA 工作溫度:0°C ~ 70°C 安裝類型:表面貼裝 封裝/外殼:16-SOIC（0.154"，3.90mm 寬） 供應商設備封裝:16-SOIC N 包裝:帶卷 (TR) |
| LTC1474CMS8 | 功能描述:IC REG BUCK ADJ 0.75A 8MSOP RoHS:否 類別:集成電路 (IC) >> PMIC - 穩(wěn)壓器 - DC DC 開關穩(wěn)壓器 系列:- 標準包裝:2,500 系列:- 類型:降壓（降壓） 輸出類型:固定 輸出數:1 輸出電壓:1.2V，1.5V，1.8V，2.5V 輸入電壓:2.7 V ~ 20 V PWM 型:- 頻率 - 開關:- 電流 - 輸出:50mA 同步整流器:是 工作溫度:-40°C ~ 125°C 安裝類型:表面貼裝 封裝/外殼:10-TFSOP，10-MSOP（0.118"，3.00mm 寬）裸露焊盤 包裝:帶卷 (TR) 供應商設備封裝:10-MSOP 裸露焊盤 |
發(fā)布緊急采購，3分鐘左右您將得到回復。