參數(shù)資料
型號： MIC2595R-2BM TR
廠商： Micrel Inc
文件頁數(shù)： 23/29頁
文件大小： 4205K
描述： IC CTRLR HOT SWAP NEG HV 14-SOIC
標(biāo)準(zhǔn)包裝： 2,500
類型： 熱交換控制器
應(yīng)用： 通用
內(nèi)部開關(guān)： 無
電源電壓： -19 V ~ -80 V
工作溫度： -40°C ~ 85°C
安裝類型： 表面貼裝
封裝/外殼： 14-SOIC（0.154"，3.90mm 寬）
供應(yīng)商設(shè)備封裝： 14-SOIC
包裝： 帶卷 (TR)
其它名稱： MIC2595R-2BMTR
MIC2595R-2BMTR-ND
Micrel
MIC2589/MIC2595
 
 
December 2005 
23
M9999-120505
 (408) 955-1690
 
higher   pulsed   power   without   damage   than   its
continuous power dissipation ratings imply due to an
inherent trait, thermal inertia. With respect to the
specification   and   use   of   power   MOSFETs,   the
parameter of interest is the Transient Thermal
Impedance, or Z
?/DIV>
, which is a real number (variable
factor) used as a multiplier of the thermal resistance
(R
?/DIV>
). The multiplier is determined using the given
Transient Thermal Impedance Graph, normalized to
R
?/DIV>
, that displays curves for the thermal impedance
versus power pulse duration and duty cycle. The
single-pulse curve is appropriate for most hot swap
applications. Z
?/DIV>
 is specified from junction-to-case for
power    MOSFETs    typically    used    in    telecom
applications.
The   following   example   provides   a   method   for
estimating the peak junction temperature of a power
MOSFET in determining if the MOSFET is suitable for
a
particular
application.
V
IN
 (VDD  VEE) = 48V, I
LIM
 = 4.2A, t
FLT
 is 20ms, and
the power MOSFET is the SUM110N10-09 (TO-263
package) from Vishay-Siliconix. This MOSFET has an
R
ON
  of 9.5m& (T
J
  = 25癈), the junction-to-case
thermal resistance (R
?J-C)
) is 0.4癈/W, junction-to-
ambient thermal resistance (R
?J-A)
) is 40癈/W, and the
Transient Thermal Impedance Curve is shown in
Figure 8. Consider, say, the MOSFET is switched on
at time t1 and the steady-state load current passing
through the MOSFET is 3A. At some point in time
after t1, at time t2, there is an unexpected short-circuit
applied to the load, causing the MIC2589/MIC2595
controller to adjust the GATE output voltage and
regulate the load current for 20ms at the programmed
current limit value, 4.2A in this example. During this
short-circuit load condition, the dissipation in the
MOSFET is calculated by:
P
D
(short) = V
DS
 ?I
LIM
 ; V
DS
 = 0V  (-48V) = 48V
P
D
(short) = 48V ?4.2A = 201.6W for 20ms.
At first glance, it would appear that a very hefty
MOSFET   is   required   to   withstand   this   extreme
overload condition. Upon further examination, the
calculation   to   approximate   the   peak   junction
temperature is not a difficult task. The first step is to
determine   the   maximum   steady-state   junction
temperature, then add the rise in temperature due to
the maximum power dissipated during a transient
overload caused by a short circuit condition. The
equation   to   estimate   the   maximum   steady-state
junction temperature is given by:
T
J
(steady-state) E T
C
(max) + T
J
 
 
(1)
T
C
(max) is the highest anticipated case temperature,
prior to an overcurrent condition, at which the
MOSFET will operate and is estimated from the
following equation based on the highest ambient
temperature of the system environment.
T
C
(max) = T
A
(max) + P
D
 ?(R
?J-A)
  R
?J-C)
)
(2)
Lets assume a maximum ambient of 60癈. The
power dissipation of the MOSFET is determined by
the current through the MOSFET and the ON
resistance (I
2
R
ON
), which we will estimate at 17m&
(specification given at T
J
  = 125癈). Using our
example information and substituting into Equation 2,
T
C
(max)     = 60癈+[((3A)
2
?7m&)?400.4)癈/W]
 
= 66.06癈
Substituting the variables into Equation 1, T
J
  is
determined by:
T
J
(steady-state) ET
C
(max)+[R
O N
+(T
C
(max)T
C
)(0.005)
 
 
?(R
O N
)][I
2
?R
?(J -A )
R
?( J- C)
)]
 
E 66.06癈+[17m&+(66.06癈25癈)(0.005/癈)
 
 
?17m&)][(3A)
2
?400.4)癈/W]
 
E 66.06癈 + 7.30癈
 
E 73.36癈
Since this is not a closed-form equation, getting a
close approximation may take one or two iterations.
On the second iteration, start with T
J
  equal to the
value calculated above. Doing so in this example
yields;
T
J
(steady-state) E66.06癈+[17m&+(73.36癈
 
 
-25癈)?0.005/癈)
?17m&)][(3A)
2
?400.4)]癈/W
 
E73.62癈
Another iteration shows that the result (73.63癈) is
converging quickly, so well estimate the maximum
T
J(steady-state)
at 74癈.
The use of the Transient Thermal Impedance Curves
is necessary to determine the increase in junction
temperature associated with a worst-case transient
condition. From our previous calculation of the
maximum power dissipated during a short circuit
event for the MIC2589/MIC2595, we calculate the
transient junction temperature increase as:
T
J
(transient) = P
D
(short) ?R
?J-C)
 ?Multiplier
(3)
Assume the MOSFET has been on for a long time 
several minutes or more  and delivering the steady-
state load current of 3A to the load when the load is
short circuited. The controller will regulate the GATE
output voltage to limit the current to the programmed
value of 4.2A for 20ms before immediately shutting off
the output. For this situation and almost all hot swap
applications, this can be considered a single pulse
event as there is no significant duty cycle. From
Figure 8, find the point on the X-axis (Square-Wave
Pulse Duration) for 25ms, allowing for a 25% margin
相關(guān)PDF資料
PDF描述
MIC280-7BM6 TR IC SUPERVISOR THERMAL SOT23-6
MIC2800-GFSYML TR IC REG TRPL BUCK/LINEAR 16MLF
MIC281-7BM6 TR IC SUPERVISOR THERMAL SOT23-6
MIC2810-1JGMYML TR IC REG TRPL BUCK/LINEAR 16MLF
MIC284-2BMM TR IC SUPERVISOR THERM 2ZONE 8-MSOP
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
MIC2595R-2YM 功能描述:熱插拔功率分布 Negative Voltage Hot-Swap Controller - Lead Free RoHS:否 制造商:Texas Instruments 產(chǎn)品:Controllers & Switches 電流限制: 電源電壓-最大:7 V 電源電壓-最小:- 0.3 V 工作溫度范圍: 功率耗散: 安裝風(fēng)格:SMD/SMT 封裝 / 箱體:MSOP-8 封裝:Tube
MIC2595R-2YM TR 功能描述:熱插拔功率分布 Negative Voltage Hot-Swap Controller - Lead Free RoHS:否 制造商:Texas Instruments 產(chǎn)品:Controllers & Switches 電流限制: 電源電壓-最大:7 V 電源電壓-最小:- 0.3 V 工作溫度范圍: 功率耗散: 安裝風(fēng)格:SMD/SMT 封裝 / 箱體:MSOP-8 封裝:Tube
MIC2595R-2YM-TR 功能描述:Hot Swap Controller, Sequencer 1 Channel -48V 14-SOIC 制造商:microchip technology 系列:- 包裝:剪切帶（CT） 零件狀態(tài):停產(chǎn) 類型:熱交換控制器，序列發(fā)生器 通道數(shù):1 內(nèi)部開關(guān):無 應(yīng)用:-48V 特性:自動重試 可編程特性:限流，故障超時，UVLO 電壓 - 電源:-80 V ~ -19 V 電流 - 輸出（最大值）:- 工作溫度:-40°C ~ 85°C 電流 - 電源:4mA 安裝類型:表面貼裝 封裝/外殼:14-SOIC（0.154"，3.90mm 寬） 供應(yīng)商器件封裝:14-SOIC 功能引腳:CFILTER，CNLD，DRAIN，PGTIMER，OFF，ON，/PWRGD1，/PWRGD2，/PWRGD3 標(biāo)準(zhǔn)包裝:1
MIC2596-1BTS 功能描述:IC SWITCH HOT SWAP DUAL 20-TSSOP RoHS:否 類別:集成電路 (IC) >> PMIC - 熱交換 系列:- 產(chǎn)品培訓(xùn)模塊:Obsolescence Mitigation Program 標(biāo)準(zhǔn)包裝:100 系列:- 類型:熱插拔開關(guān) 應(yīng)用:通用 內(nèi)部開關(guān):是 電流限制:可調(diào) 電源電壓:9 V ~ 13.2 V 工作溫度:-40°C ~ 150°C 安裝類型:表面貼裝 封裝/外殼:10-WFDFN 裸露焊盤 供應(yīng)商設(shè)備封裝:10-TDFN-EP（3x3） 包裝:管件
MIC2596-1BTS TR 功能描述:IC SWITCH HOT SWAP DUAL 20-TSSOP RoHS:否 類別:集成電路 (IC) >> PMIC - 熱交換 系列:- 產(chǎn)品培訓(xùn)模塊:Obsolescence Mitigation Program 標(biāo)準(zhǔn)包裝:100 系列:- 類型:熱插拔開關(guān) 應(yīng)用:通用 內(nèi)部開關(guān):是 電流限制:可調(diào) 電源電壓:9 V ~ 13.2 V 工作溫度:-40°C ~ 150°C 安裝類型:表面貼裝 封裝/外殼:10-WFDFN 裸露焊盤 供應(yīng)商設(shè)備封裝:10-TDFN-EP（3x3） 包裝:管件
發(fā)布緊急采購，3分鐘左右您將得到回復(fù)。

采購需求

(若只采購一條型號，填寫一行即可)

發(fā)布成功！您可以繼續(xù)發(fā)布采購。也可以進(jìn)入我的后臺，查看報價

發(fā)布成功！您可以繼續(xù)發(fā)布采購。也可以進(jìn)入我的后臺，查看報價

*型號 *數(shù)量 廠商 批號 封裝
添加更多采購

我的聯(lián)系方式

*
*
*