參數(shù)資料
型號(hào): MAX5938LEEE+
廠商: Maxim Integrated
文件頁(yè)數(shù): 11/26頁(yè)
文件大?。?/td> 915K
描述: IC HOT-SWAP CTRLR -48V 16-QSOP
產(chǎn)品培訓(xùn)模塊: Lead (SnPb) Finish for COTS
Obsolescence Mitigation Program
標(biāo)準(zhǔn)包裝: 100
類型: 熱交換控制器
應(yīng)用: 通用
內(nèi)部開關(guān):
電源電壓: -10 V ~ -80 V
工作溫度: -40°C ~ 85°C
安裝類型: 表面貼裝
封裝/外殼: 16-SSOP(0.154",3.90mm 寬)
供應(yīng)商設(shè)備封裝: 16-QSOP
包裝: 管件
-48V Hot-Swap Controller with V
IN
Step Immunity,
No R
SENSE
, and Overvoltage Protection
______________________________________________________________________________________   11
Fault Management
Fault management can be triggered by the following
conditions:
" V
OUT
exceeds 74% of V
CB
during GATE ramp at
90% of full enhancement,
" V
OUT
exceeds the V
CB
for longer than 1.2ms during
full enhancement,
" V
OUT
exceeds the V
SC
during full enhancement,
"  Load-probe test fails,
" V
IN
exceeds the programmed overvoltage (OV) limit
for more than 1.5ms.
Once in the fault management mode, GATE will always be
pulled to V
EE
, which turns off the external MOSFET and
always deasserts PGOOD. If CB_ADJ is left open, short-
circuit and circuit-breaker faults are ignored. The
MAX5938A version has automatic retry following a fault
while the MAX5938L remains latched in the fault condition.
Autoretry Fault Management (MAX5938A)
If the MAX5938A entered fault management due to an
OV fault, it will start the autoretry timer when the OV
fault is removed. For circuit-breaker and short-circuit
faults, the autoretry timer starts immediately. The timer
times out in 3.5s (typ) after which the sequencer initi-
ates a load-probe test and if successful, initiates a nor-
mal power-up GATE cycle.
Latched Fault Management (MAX5938L)
When the MAX5938L enters fault management it
remains in this condition indefinitely until the power is
recycled or until OFF is brought below 1.25V (no time
dependence) and ON is brought below 1.125V for
1.5ms (typ). In addition, if the MAX5938L enters fault
management due to an overvoltage fault, the overvolt-
age fault must be removed. When the last of these con-
ditions has been met, the sequencer initiates a load-
probe test and if successful, a normal power-up GATE
cycle begins. A manual reset circuit as in Figure 2 can
be used to clear the latch.
Circuit-Breaker Threshold
The MAX5938 has a minimum circuit-breaker threshold
voltage of 50mV when CB_ADJ is connected to V
EE
. The
V
CB
is half V
SC
and can be increased by placing a resis-
tor between CB_ADJ and V
EE
according to the following:
V
CB
(mV) =
1
/
2
x V
SC
(mV) =
1
/
2
x I
CB_ADJ
(礎(chǔ))
x [R
INT
(k&) + R
CB_ADJ
(k&)]
where I
CB_ADJ
= 50礎(chǔ) (typ at +25癈), R
INT
is an internal
precision, ?.5%, 2k& resistor at CB_ADJ and R
CB_ADJ
is the external resistor between CB_ADJ and V
EE
. The
current source I
CB_ADJ
is temperature-compensated
(increasing with temperature) to track the normalized
temperature coefficient of typical power MOSFETs.
The proper circuit-breaker threshold for an application
depends on the R
DS(ON)
of the external power MOSFET
and the maximum current the load is expected to draw.
To avoid false fault indication and dropping of the load,
the designer must take into account the load response to
voltage ripples and noise from the backplane power sup-
ply as well as switching currents in the downstream DC-
DC converter that is loading the circuit. While the
circuit-breaker threshold has glitch rejection that ignores
ripples and noise lasting less than 1.2ms, the short-cir-
cuit detection is designed to respond very quickly (less
than 330ns) to a short circuit. For this reason, set V
SC
and V
CB
with an adequate margin to cover all possible
ripples, noise, and system current transients (see the
Setting the Circuit-Breaker and Short-Circuit Thresholds
section in the Applications Information).
Figure 8. Resetting the MAX5938L after a Fault Condition
Using a Push-Button Switch
MAX5938
GND
OFF
ON
V
IN
 = (GND - V
EE
)
R4
R3
R2
R1
OV
V
EE
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MAX5938LEEE+ 功能描述:熱插拔功率分布 48V- Hot-Swap Controller 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
MAX5938LEEE+T 功能描述:熱插拔功率分布 48V- Hot-Swap Controller 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
MAX5938LEEE-T 功能描述:熱插拔功率分布 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
MAX5939AESA 功能描述:熱插拔功率分布 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
MAX5939AESA+ 功能描述:熱插拔功率分布 48V- Hot-Swap Controller 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