- 您现在的位置：买卖IC网 > Datasheet目录44 > MIC2086-MBQS TR (Micrel Inc)IC CTRLR HOW SWAP SGL 20-QSOP Datasheet资料下载
参数资料
| 型号： | MIC2086-MBQS TR |
| 厂商： | Micrel Inc |
| 文件页数： | 23/29页 |
| 文件大小： | 1008K |
| 描述： | IC CTRLR HOW SWAP SGL 20-QSOP |
| 标准包装： | 2,500 |
| 类型： | 热交换控制器 |
| 应用： | 通用型 Infiniband? |
| 内部开关： | 无 |
| 电源电压： | 2.3 V ~ 16.5 V |
| 工作温度： | -40°C ~ 85°C |
| 安装类型： | 表面贴装 |
| 封装/外壳： | 20-SSOP（0.154"，3.90mm 宽） |
| 供应商设备封装： | 20-QSOP |
| 包装： | 带卷 (TR) |
| 其它名称： | MIC2086-MBQSTR MIC2086-MBQSTR-ND |
第1页第2页第3页第4页第5页第6页第7页第8页第9页第10页第11页第12页第13页第14页第15页第16页第17页第18页第19页第20页第21页第22页当前第23页第24页第25页第26页第27页第28页第29页
Micrel, Inc.
MIC2085/2086
May 2006
23
M9999-050406
(408) 955-1690
MOSFET Voltage Requirements
The first voltage requirement for the MOSFET is that the
drain-source breakdown voltage of the MOSFET must
be greater than V
IN(MAX)
. For instance, a 16V input may
reasonably be expected to see high-frequency transients
as high as 24V.Therefore, the drain-source breakdown
voltage of the MOSFET must be at least 25V. For ample
safety margin and standard availability, the closest
minimum value should be 30V.
The second breakdown voltage criterion that must be
met is a bit subtler than simple drain-source breakdown
voltage. In MIC2085/86 applications, the gate of the
external MOSFET is driven up to a maximum of 21V by
the internal output MOSFET. At the same time, if the
output of the external MOSFET (its source) is suddenly
subjected to a short, the gate-source voltage will go to
(21V 0V) = 21V. Since most power MOSFETs
generally have a maximum gate-source breakdown of
20V or less, the use of a Zener clamp is recommended
in applications with V
CC
e 8V. A Zener diode with 10V to
12V rating is recommended as shown in Figure11. At the
present time, most power MOSFETs with a 20V gate-
source voltage rating have a 30V drain-source break-
down rating or higher. As a general tip, choose surface-
mount devices with a drain-source rating of 30V or more
as a starting point.
Finally, the external gate drive of the MIC2085/86
requires a low-voltage logic level MOSFET when
operating at voltage slower than 3V. There are 2.5V
logic-level MOSFETs avail-able. Please see Table 4,
MOSFET and Sense Resistor Vendors for suggested
manufacturers.
MOSFET Steady-State Thermal Issues
The selection of a MOSFET to meet the maximum
continuous current is a fairly straightforward exercise.
First, arm yourself with the following data:
" The value of I
LOAD(CONT, MAX.)
for the output in
question (see Sense Resistor Selection ).
" The manufacturers data sheet for the candidate
MOSFET.
" The maximum ambient temperature in which the
device will be required to operate.
" Any knowledge you can get about the heat
sinking available to the device (e.g., can heat be
dissipated into the ground plane or power plane,
if using a surface-mount part? Is any airflow
available?).
The data sheet will almost always give a value of on
resistance given for the MOSFET at a gate-source
voltage of 4.5V, and another value at a gate-source
voltage of 10V. As a first approximation, add the two
values together and divide by two to get the on-
resistance of the part with 8V of enhancement. Call this
value R
ON
. Since a heavily enhanced MOSFET acts as
an ohmic (resistive) device, almost all thats required to
determine steady-state power dissipation is to calculate
I2R.The one addendum to this is that MOSFETs have a
slight increase in R
ON
with increasing die temperature. A
good approximation for this value is 0.5% increase in
R
ON
per 癈 rise in junction temperature above the point
at which R
ON
was initially specified by the manufacturer.
For instance, if the selected MOSFET has a calculated
R
ON
of 10m& at a T
J
= 25癈, and the actual junction
temperature ends up at 110癈, a good first cut at the
operating value for R
ON
would be:
R
ON
E 10m&[1 + (110 - 25)(0.005)] E14.3m&
The final step is to make sure that the heat sinking
available to the MOSFET is capable of dissipating at
least as much power (rated in 癈/W) as that with which
the MOSFETs performance was specified by the
manufacturer. Here are a few practical tips:
1. The heat from a surface-mount device such a
san SO-8 MOSFET flows almost entirely out of
the drain leads. If the drain leads can be
soldered down to one square inch or more, the
copper will act as the heat sink for the part. This
copper must be on the same layer of the board
as the MOSFET drain.
相关PDF资料 |
PDF描述 |
|---|---|
| MIC2225-4OYMT TR | IC REG DL BUCK/LINEAR 10TMLF |
| MIC2310-2ZTS TR | IC HOT SWAP CTLR 2CHAN 24TSSOP |
| MIC2341-2YTQ | IC HOT PLUG CTLR DUAL PCI 48TQFP |
| MIC2569YQS TR | IC POWER SWITCH CABLECARD 16QSOP |
| MIC2583R-MBQS TR | IC CTRLR HOT SWAP 200MV 16-QSOP |
相关代理商/技术参数 |
参数描述 |
|---|---|
| MIC2086-XBQS | 制造商:MICREL 制造商全称:Micrel Semiconductor 功能描述:Single Channel Hot Swap Controllers |
| MIC2090 | 制造商:MICREL 制造商全称:Micrel Semiconductor 功能描述:Current Limiting Power Distribution Switches |
| MIC2090_11 | 制造商:MICREL 制造商全称:Micrel Semiconductor 功能描述:Current Limiting Power Distribution Switches |
| MIC2090-1YM5 | 制造商:MICREL 制造商全称:Micrel Semiconductor 功能描述:Current Limiting Power Distribution Switches |
| MIC2090-1YM5 TR | 功能描述:电源开关 IC - USB 50mA Current Limiting Power Distribution Switch RoHS:否 制造商:Micrel 电源电压-最小:2.7 V 电源电压-最大:5.5 V 最大工作温度:+ 85 C 最小工作温度:- 40 C 封装 / 箱体:SOIC-8 封装:Tube |
发布紧急采购，3分钟左右您将得到回复。