参数资料
| 型号： | ISL6144EVAL1 |
| 厂商： | Intersil |
| 文件页数： | 23/30页 |
| 文件大小： | 0K |
| 描述： | EVALUATION BOARD ISL6144 ORING |
| 标准包装： | 1 |
| 主要目的： | 电源管理，O 环控制器/负荷分载 |
| 已用 IC / 零件： | ISL6144 |
| 已供物品： | 板 |
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ISL6144
This shows that worst-case failure scenario has to be
accounted for when choosing the ORing MOSFET. In both
cases, more than one ORing MOSFET/diode has to be
paralleled on each feed. Using parallel devices reduces
power dissipation per device and limits the junction
temperature rise to acceptable safe levels. Another
alternative is to choose a MOSFET with lower r DS(ON)
(Refer to Tables 1 and 2 for some examples).
If parallel MOSFETs are used on each feed, make sure to
use the same part number. Also it is preferable to have parts
from the same lot to insure load sharing between these
paralleled devices.
The final choice of the N-Channel ORing MOSFET depends
on the following aspects:
? Voltage Rating: The drain-source breakdown voltage
V DSS has to be higher than the maximum input voltage,
including transients and spikes. Also, the gate to source
voltage rating has to be considered. The ISL6144
maximum Gate charge voltage is 12V. Make sure the used
MOSFET has a maximum V GS rating >12V.
? Power Losses: In this application, the ORing MOSFET is
used as a series pass element, which is normally fully
enhanced at high load currents. Switching losses are
negligible. The major losses are conduction losses, which
depend on the value of the on-state resistance of the
MOSFET r DS(ON) , and the per feed load current. For an
N + 1 redundant system with perfect current sharing, the
? Current handling capability, steady state and peak, are
also two important parameters that must be considered.
The limitation on the maximum allowable drain current
comes from limitation on the maximum allowable device
junction temperature. The thermal board design has to be
able to dissipate the resulting heat without exceeding the
MOSFET’s allowable junction temperature.
Suppose P Loss = 1W in a D2PAK MOSFET, junction to
ambient thermal resistance R θ JA = +43°C/W (with 1 inch 2
copper pad area), T JMAX = +175°C, r DS(ON) = 4.5m Ω ,
maximum ambient board temperature = +85°C.
We need to make sure that the MOSFET’s junction
temperature during operation does not exceed the maximum
allowable device junction temperature.
T J = T A_max + P Loss ? R θ JA
T J = +85°C+1W. +43°C/W = +128°C
T J < T JMAX
In the example of Figure 30 with a load of 32A, at least 3
MOSFETs with r DS(ON) = 4.5m Ω are paralleled to limit the
dissipation to below 1W and operate with safe junction
temperature.
Tables 1 and 2 show MOSFET selection for some typical
applications with different input voltages and load currents in
a 1 + 1 redundant power system (a maximum of 1W of
power dissipation across each MOSFET is assumed).
P loss ( FET ) = ? ----------------- ? ? r DS ( ON )
per feed MOSFET losses are:
I LOAD 2
? N + 1 ?
(EQ. 14)
For a 48V Input:
TABLE 1. INPUT VOLTAGE = 48V
? The final MOSFET selection has to be based on the worse
case current when the system is reduced to N parallel
supplies due to a permanent failure of one unit. The
remaining units have to provide the full load current. In this
case, losses across each remaining ORing MOSFET
become Equation 15:
I Load_Max
8A
16A
MOSFET PART NUMBER
FDB3632 (Note 14)
SUM110N10-08 (Note 15)
FDB3632 (Note 14)
SUM110N10-08
FDB045AN08A0 (Note 16)
N (Note 13)
1
1
2
2
1
P loss ( FET ) = ? ----------------- ? ? r DS ( ON )
? N ?
I LOAD 2
(EQ. 15)
32A
FDB3632 (Note 14)
SUM110N10-08
FDB045AN08A0
4
4
3
? In the particular cases illustrated in the previous examples
of Figures 29 and 30 with N = 1, each of the two ORing
feeds have to be able to handle the full load current.
? The MOSFET’s r DS(ON) value also depends on junction
temperature; a curve showing this relationship is usually
part of any MOSFET’s data sheet. The increase in the
value of the r DS(ON) over-temperature has to be taken into
account.
23
NOTES:
13. Number of parallel MOSFETs per feed
14. V DSS = 100V;I D = 80A; r DS(ON) = 9m Ω
15. V DSS = 100V; I D = 110A; r DS(ON) = 9.5m Ω
16. V DSS = 75V; I D = 80A; r DS(ON) = 4.5m Ω
FN9131.7
October 6, 2011
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相关代理商/技术参数 |
参数描述 |
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| ISL6144EVAL1Z | 功能描述:EVALUATION BOARD ISL6144 ORING RoHS:是 类别:编程器，开发系统 >> 评估演示板和套件 系列:- 标准包装:1 系列:PCI Express® (PCIe) 主要目的:接口，收发器，PCI Express 嵌入式:- 已用 IC / 零件:DS80PCI800 主要属性:- 次要属性:- 已供物品:板 |
| ISL6144IR | 功能描述:IC CTRLR MOSFET HV ORING 20-QFN RoHS:否 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) |
| ISL6144IR-T | 功能描述:IC CTRLR MOSFET HV ORING 20-QFN RoHS:否 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) |
| ISL6144IRZA | 功能描述:热插拔功率分布 W/ANNEAL 20LD 5X5 QF N ORING FET CONTRLR RoHS:否 制造商:Texas Instruments 产品:Controllers & Switches 电流限制: 电源电压-最大:7 V 电源电压-最小:- 0.3 V 工作温度范围: 功率耗散: 安装风格:SMD/SMT 封装 / 箱体:MSOP-8 封装:Tube |
| ISL6144IRZA-T | 功能描述:IC CTRLR MOSFET HV ORING 20-QFN 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) |
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