参数资料
型号: MAX5946AETX+T
厂商: Maxim Integrated
文件页数: 17/23页
文件大小: 1102K
描述: IC CNTRLR PCI EXP DL 36TQFN
产品培训模块: Lead (SnPb) Finish for COTS
Obsolescence Mitigation Program
标准包装: 2,500
类型: 热交换控制器
应用: 通用型,PCI Express?
内部开关:
电源电压: 3.3V,12V
工作温度: -40°C ~ 85°C
安装类型: 表面贴装
封装/外壳: 36-WFQFN 裸露焊盘
供应商设备封装: 36-TQFN 裸露焊盘(6x6)
包装: 带卷 (TR)
FAULT Management
A fault occurs when an overcurrent lasts longer then
t
FAULT
or when the device experiences an overtemper-
ature condition.
"   A fault on a main output (12V or 3.3V) shuts down
both main outputs of the respective slot. The 3.3V
auxiliary is not affected.
"   A fault on the 3.3V auxiliary output shuts down all
three outputs of the respective slot.
The MAX5946A automatically restarts from a fault shut-
down after the t
RESTART
period, while the MAX5946L
latches off. If an overcurrent fault occurred on a main
output, bring ON_ low for at least t
RESET
(100祍) and
high again to reset the fault and restart the outputs. If
the overcurrent fault occurred on an auxiliary output or
an overtemperature fault occurred, bring both ON_ and
AUXON_ low for a minimum of t
RESET
to reset the fault.
Bring ON_ and/or AUXON_ high again to restart the
respective outputs. As an extra protection, the
MAX5946L waits a minimum of t
RESTART
before it can
be restarted.
Debounced Logic Gate
(Input_ and Output_)
INPUT1 and INPUT2 accept inputs from mechanical
switches. The corresponding outputs are OUTPUT1
and OUTPUT2. OUTPUT_ is debounced for 4ms. When
INPUT_ goes from high to low, OUTPUT_ goes low right
away and stays low for at least 4ms. After the
debounce time OUTPUT_ follows INPUT_. If INPUT_
goes from low to high, OUTPUT_ goes high right away
and stays high for at least 4ms. After the debounce
time, OUTPUT_ follows INPUT_. Figure 5 shows the tim-
ing diagram describing the INPUT_/OUTPUT_
debounced feature.
Present-Detect and Forced-On Inputs
(PPRREESS- -DDEETT__,,  FFOON  N__)
PRES-DETA and PRES-DETB inputs detect the
PRSNT#2 pin on a PCI express connector. When the
card is plugged in, PRES-DET_ goes low and allows
the turn-on of the outputs of the respective slot after a
4ms debounced time. When the card is removed, an
internal 50k& pullup forces PRES-DET_ high and the
respective slot is shut down with no delay. PRES-DET_
works in conjunction with ON_ and VAUXON_ and only
enables the device when ON_ and VAUXON_ are high.
A logic-low on FON_ forces the respective slot (main
supplies and auxiliary) to turn on regardless of the sta-
tus of the other logic inputs provided the UVLO thresh-
olds are exceeded on all of the inputs.
Active Current Limits
Active current limits are provided for all three outputs of
slot A and slot B. Connect a current-sense resistor
between 12S_+ and 12S_- to set the current limit for the
12V outputs. The current limit is set to 54mV/R
SENSE12
.
R
SENSE12
is either R1 or R3 in the Typical Application
Circuit. Connect a current-sense resistor between
3.3S_+ and 3.3S_- to set the current limit for the 3.3V
main outputs to 20mV/R
SENSE3.3
. R
SENSE3.3
is either R2
or R4 in the Typical Application Circuit. For the auxiliary
output (3.3V
AUXO_
) the current limit is fixed at 470mA.
When the voltage across R
SENSE12
or R
SENSE3.3
reaches the current-limit threshold voltage, the
MAX5946 regulates the gate voltage to maintain the
current-limit threshold voltage across the sense resis-
tor. If the current limit lasts for t
FAULT
then an overcur-
rent fault occurs. The MAX5946_ shuts down both the
12V and 3.3V outputs and asserts the FAULT_ output of
the respective slot.
When the auxiliary output reaches the current limit
(470mA) for longer then t
FAULT
, a fault occurs and the
device shuts down all outputs and asserts FAULT of the
respective slot.
Undervoltage Lockout Threshold
The UVLO thresholds prevent the internal auxiliary
MOSFETs and the external main channel MOSFETs
(Q1Q4 in the Typical Application Circuit) from turning
on if V
12VIN
, V
3.3VIN
, and V
3.3VAUXIN
are not present.
Internal comparators monitor the main supplies and the
auxiliary supply and keep the gate-drive outputs
(12GA, 12GB, 3.3GA, and 3.3GB) low until the supplies
rise above their UVLO threshold. The 12V main supply
is monitored at 12VIN and has a UVLO threshold of
10V. The 3.3V main supply is monitored at 3.3SA+ and
has a UVLO threshold of 2.65V. The auxiliary supply is
monitored at 3.3VAUXIN and has a 2.65V UVLO thresh-
old. For either main channel to operate, V
3.3VAUXIN
must be above its UVLO threshold.
Dual PCI Express, Hot-Plug
Controller
______________________________________________________________________________________   17
INPUT
DEBOUNCED
OUTPUT
t
DBC
t
DBC
t
DBC
Figure 5. INPUT_ and OUTPUT_ Debounced Feature
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MAX5946LETJ 制造商:Maxim Integrated Products 功能描述:DUAL PCI-EXPRESS HOT-PLUG CONTROLLER - Rail/Tube
MAX5946LETX 功能描述:热插拔功率分布 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
MAX5946LETX+ 功能描述:热插拔功率分布 Dual PCIe Hot-Plug Controller 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
MAX5946LETX+T 功能描述:热插拔功率分布 Dual PCIe Hot-Plug Controller 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
MAX5946LETX-T 功能描述:热插拔功率分布 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