- 您现在的位置：买卖IC网 > PDF目录30772 > LTC4355IDE (LINEAR TECHNOLOGY CORP) 1-CHANNEL POWER SUPPLY SUPPORT CKT, PDSO14 PDF资料下载
参数资料
| 型号： | LTC4355IDE |
| 厂商： | LINEAR TECHNOLOGY CORP |
| 元件分类： | 电源管理 |
| 英文描述： | 1-CHANNEL POWER SUPPLY SUPPORT CKT, PDSO14 |
| 封装： | 4 X 3 MM, PLASTIC, MO-229WGED-3, DFN-14 |
| 文件页数： | 14/16页 |
| 文件大小： | 221K |
| 代理商： | LTC4355IDE |
LTC4355
7
4355f
OPERATION
High availability systems often employ parallel-connected
power supplies or battery feeds to achieve redundancy
and enhance system reliability. ORing diodes have been
a popular means of connecting these supplies at the point
of load. The disadvantage of this approach is the forward
voltage drop and resulting efciency loss. This drop reduces
the available supply voltage and dissipates signicant
power. Using N-channel MOSFETs to replace Schottky
diodes reduces the power dissipation and eliminates the
need for costly heat sinks or large thermal layouts in high
power applications.
The LTC4355 is a positive voltage diode-OR controller that
drives two external N-channel MOSFETs as pass transis-
tors to replace ORing diodes. The IN and OUT pins form
the anodes and cathodes of the ideal diodes. The source
pins of the external MOSFETs are connected to the IN pins.
The drains of the MOSFETs are connected together at the
OUT pin, which is the positive supply of the device. The
gates of the external MOSFETs are driven by the LTC4355
to regulate the voltage drop across the pass transistors.
At power-up, the initial load current ows through the
body diode of the MOSFET with the higher INx voltage.
The associated GATEx pin immediately ramps up and turns
on the MOSFET. The amplier tries to regulate the voltage
drop across the source and drain connections to 25mV.
If the load current causes more than 25mV of drop, the
MOSFET gate is driven fully on and the voltage drop is
equal to RDS(ON) ILOAD.
When the power supply voltages are nearly equal, this
regulation technique ensures that the load current is
smoothly shared between the MOSFETs without oscil-
lation. The current owing through each pass trans-
istor depends on the RDS(ON) of each MOSFET and the
output impedances of the supplies.
In the event of a supply failure, such as if the supply that
is conducting most or all of the current is shorted to GND,
reverse current ows temporarily through the MOSFET that
is on. This current is sourced from any load capacitance
and from the second supply through the body diode of
the other MOSFET. The LTC4355 quickly responds to this
condition, turning off the MOSFET in about 500ns. This
fast turn-off prevents the reverse current from ramping
up to a damaging level.
In the case where the pass transistor is fully on but the
voltage drop across it exceeds the congurable fault
threshold, ΔVSD(FLT), the VDSFLT pin pulls low. Using this
pin to shunt current away from an LED or optocoupler
provides an indication that a pass transistor has either
failed or has excessive forward current. Additionally, in
this condition the
PWRFLT1 or PWRFLT2 pin pulls low
to identify the faulting channel.
The
PWRFLT pins also indicate if an input supply is within
regulation. When VMON1 < 1.23V or VMON2 < 1.23V, the
corresponding
PWRFLT pin pulls low to indicate that
the input supply is low, turning off an optional LED or
optocoupler.
The
FUSEFLT pins indicate the status of input fuses. If
the voltage at one of the IN pins is less than 3.5V, the
corresponding
FUSEFLT pin pulls low. The IN pins sink
a minimum of 0.5mA to guarantee that the IN pin will
pull low when the input fuse is blown open. Note that the
FUSEFLT pin will activate if the input supply is less than
3.5V even if the fuse is intact.
相关PDF资料 |
PDF描述 |
|---|---|
| LTC4355CDE | 1-CHANNEL POWER SUPPLY SUPPORT CKT, PDSO14 |
| LTC4355IS#TR | 1-CHANNEL POWER SUPPLY SUPPORT CKT, PDSO16 |
| LTC4361CDC-1#TRPBF | 1-CHANNEL POWER SUPPLY SUPPORT CKT, PDSO8 |
| LTC4361CDC-2#TRPBF | 1-CHANNEL POWER SUPPLY SUPPORT CKT, PDSO8 |
| LTC4361IDC-1#TRMPBF | 1-CHANNEL POWER SUPPLY SUPPORT CKT, PDSO8 |
相关代理商/技术参数 |
参数描述 |
|---|---|
| LTC4355IDE#PBF | 功能描述:IC IDEAL DIODE-OR 14-DFN RoHS:是 类别:集成电路 (IC) >> PMIC - O 圈控制器 系列:- 标准包装:1,000 系列:- 应用:电池备份，工业/汽车，大电流开关 FET 型:- 输出数:5 内部开关:是 延迟时间 - 开启:100ns 延迟时间 - 关闭:- 电源电压:3 V ~ 5.5 V 电流 - 电源:250µA 工作温度:0°C ~ 70°C 安装类型:表面贴装 封装/外壳:16-SOIC（0.154"，3.90mm 宽） 供应商设备封装:16-SOIC N 包装:带卷 (TR) |
| LTC4355IDE#TRPBF | 功能描述:IC IDEAL DIODE-OR 14-DFN RoHS:是 类别:集成电路 (IC) >> PMIC - O 圈控制器 系列:- 标准包装:1,000 系列:- 应用:电池备份，工业/汽车，大电流开关 FET 型:- 输出数:5 内部开关:是 延迟时间 - 开启:100ns 延迟时间 - 关闭:- 电源电压:3 V ~ 5.5 V 电流 - 电源:250µA 工作温度:0°C ~ 70°C 安装类型:表面贴装 封装/外壳:16-SOIC（0.154"，3.90mm 宽） 供应商设备封装:16-SOIC N 包装:带卷 (TR) |
| LTC4355IMS#PBF | 功能描述:IC IDEAL DIODE-OR 16-MSOP RoHS:是 类别:集成电路 (IC) >> PMIC - O 圈控制器 系列:- 标准包装:1,000 系列:- 应用:电池备份，工业/汽车，大电流开关 FET 型:- 输出数:5 内部开关:是 延迟时间 - 开启:100ns 延迟时间 - 关闭:- 电源电压:3 V ~ 5.5 V 电流 - 电源:250µA 工作温度:0°C ~ 70°C 安装类型:表面贴装 封装/外壳:16-SOIC（0.154"，3.90mm 宽） 供应商设备封装:16-SOIC N 包装:带卷 (TR) |
| LTC4355IMS#PBF | 制造商:Linear Technology 功能描述:IC, IDEAL DIODE CTRL, HIGH VOLT, MSOP-16 |
| LTC4355IMS#TRPBF | 功能描述:IC IDEAL DIODE-OR DUAL 16-MSOP RoHS:是 类别:集成电路 (IC) >> PMIC - O 圈控制器 系列:- 标准包装:1,000 系列:- 应用:电池备份，工业/汽车，大电流开关 FET 型:- 输出数:5 内部开关:是 延迟时间 - 开启:100ns 延迟时间 - 关闭:- 电源电压:3 V ~ 5.5 V 电流 - 电源:250µA 工作温度:0°C ~ 70°C 安装类型:表面贴装 封装/外壳:16-SOIC（0.154"，3.90mm 宽） 供应商设备封装:16-SOIC N 包装:带卷 (TR) |
发布紧急采购，3分钟左右您将得到回复。