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参数资料
| 型号： | LTC4252-2CMS8#TRPBF |
| 厂商： | LINEAR TECHNOLOGY CORP |
| 元件分类： | 电源管理 |
| 英文描述： | Negative Voltage Hot Swap Controllers; Package: MSOP; No of Pins: 8; Temperature Range: 0°C to +70°C |
| 中文描述： | 2-CHANNEL POWER SUPPLY SUPPORT CKT, PDSO8 |
| 封装： | LEAD FREE, PLASTIC, MSOP-8 |
| 文件页数： | 4/36页 |
| 文件大小： | 336K |
| 代理商： | LTC4252-2CMS8#TRPBF |
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LTC4252-1/LTC4252-2
LTC4252A-1/LTC4252A-2
12
425212fc
OPERATION
Hot Circuit Insertion
When circuit boards are inserted into a live backplane, the
supply bypass capacitors can draw huge transient currents
from the power bus as they charge. The flow of current
damages the connector pins and glitches the power bus,
causing other boards in the system to reset. The LTC4252
is designed to turn on a circuit board supply in a controlled
manner, allowing insertion or removal without glitches or
connector damage.
Initial Start-Up
The LTC4252 resides on a removable circuit board and
controls the path between the connector and load or power
conversion circuitry with an external MOSFET switch (see
Figure 1). Both inrush control and short-circuit protection
are provided by the MOSFET.
A detailed schematic for the LTC4252A is shown in Figure2.
– 48V and –48RTN receive power through the longest con-
nector pins and are the first to connect when the board is
inserted. The GATE pin holds the MOSFET off during this
time. UV and OV determine whether or not the MOSFET
should be turned on based upon internal high accuracy
thresholds and an external divider. UV and OV do double
duty by also monitoring whether or not the connector is
seated. The top of the divider detects –48RTN by way of
a short connector pin that is the last to mate during the
insertion sequence.
Interlock Conditions
A start-up sequence commences once these “interlock”
conditions are met.
1. The input voltage VIN exceeds VLKO (UVLO).
2. The voltage at UV > VUVHI.
3. The voltage at OV < VOVLO.
4. The (SENSE – VEE) voltage is < 50mV (VCB).
5. The voltage at SS is < 0.2V (20 VOS).
6. The voltage on the TIMER capacitor (CT) is < 1V (VTMRL).
7. The voltage at GATE is < 0.5V (VGATEL).
The first three conditions are continuously monitored and
the latter four are checked prior to initial timing or GATE
ramp-up. Upon exiting an OV condition, the TIMER pin
voltage requirement is inhibited. Details are described in
the Applications Information, Timing Waveforms section.
TIMER begins the start-up sequence by sourcing 5.8μA
into CT. If VIN, UV or OV falls out of range, the start-up
cycle stops and TIMER discharges CT to less than 1V, then
waits until the aforementioned conditions are once again
met. If CT successfully charges to 4V, TIMER pulls low
and both SS and GATE pins are released. GATE sources
58μA (IGATE), charging the MOSFET gate and associated
capacitance. The SS voltage ramp limits VSENSE to control
the inrush current. PWRGD pulls active low when GATE is
within 2.8V of VIN and DRAIN is lower than VDRNL.
4252-1/2 F01
LTC4252
CLOAD
ISOLATED
DC/DC
CONVERTER
MODULE
LOW
VOLTAGE
CIRCUITRY
++
––
PLUG-IN BOARD
BACKPLANE
–48RTN
–48V
LONG
+
Figure 1. Basic LTC4252 Hot Swap Topology
Figure 2. –48V, 2.5A Hot Swap Controller
425212 F02
–48RTN
–48V
UV
OV
TIMER
VEE
VIN
SENSE GATE
SS
DRAIN
LTC4252A-1
R1
392k
1%
DIN
+
DDZ13B**
R2
30.1k
1%
RD
1M
CT
0.68μF
CSS
68nF
CC
10nF
RS
0.02Ω
Q1
IRF530S
RC
10Ω
RIN
3
× 1.8k IN SERIES
1/4W EACH
C1
10nF
CIN
1μF
CLOAD
100μF
LONG
SHORT
+
**DIODES, INC
RECOMMENDED FOR HARSH ENVIRONMENTS
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| LTC4252-2IMS8#PBF | Negative Voltage Hot Swap Controllers; Package: MSOP; No of Pins: 8; Temperature Range: -40°C to +85°C |
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相关代理商/技术参数 |
参数描述 |
|---|---|
| LTC4252-2CMSPBF | 制造商:LINER 制造商全称:Linear Technology 功能描述:Negative Voltage Hot Swap Controllers |
| LTC4252-2CMSTR | 制造商:LINER 制造商全称:Linear Technology 功能描述:Negative Voltage Hot Swap Controllers |
| LTC4252-2CMSTRPBF | 制造商:LINER 制造商全称:Linear Technology 功能描述:Negative Voltage Hot Swap Controllers |
| LTC4252-2IMS | 功能描述:IC CNTRLR HOTSWAP NEGVOLT 10MSOP RoHS:否 类别:集成电路 (IC) >> PMIC - 热交换 系列:- 标准包装:50 系列:- 类型:热交换控制器 应用:-48V 远程电力系统，AdvancedTCA ? 系统，高可用性 内部开关:无 电流限制:可调 电源电压:11.5 V ~ 14.5 V 工作温度:-40°C ~ 85°C 安装类型:表面贴装 封装/外壳:10-TFSOP，10-MSOP（0.118"，3.00mm 宽） 供应商设备封装:10-MSOP 包装:管件 |
| LTC4252-2IMS#PBF | 功能描述:IC CNTRLR HOTSWAP NEGVOLT 10MSOP RoHS:是 类别:集成电路 (IC) >> PMIC - 热交换 系列:- 标准包装:50 系列:- 类型:热交换控制器 应用:-48V 远程电力系统，AdvancedTCA ? 系统，高可用性 内部开关:无 电流限制:可调 电源电压:11.5 V ~ 14.5 V 工作温度:-40°C ~ 85°C 安装类型:表面贴装 封装/外壳:10-TFSOP，10-MSOP（0.118"，3.00mm 宽） 供应商设备封装:10-MSOP 包装:管件 |
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