参数资料
型号: LTC4232CDHC#PBF
厂商: Linear Technology
文件页数: 11/16页
文件大小: 242K
描述: IC CTLR HOT SWAP 5A 16-DFN
标准包装: 73
类型: 热交换开关
应用: 服务器,储存,通信,嵌入式,消费品
内部开关:
电流限制: 可调
电源电压: 2.9 V ~ 15 V
工作温度: 0°C ~ 70°C
安装类型: 表面贴装
封装/外壳: 16-WFDFN 裸露焊盘
供应商设备封装: 16-DFN(5x3)
包装: 管件
LTC4232
11
4232fa
applicaTions inForMaTion
Current Limit Adjustment
The default value of the active current limit is 5.6A. The
current limit threshold can be adjusted lower by placing
a resistor between the I
SET
 pin and ground. As shown in
the Functional Diagram the voltage at the I
SET
 pin (via
the clamp circuit) sets the CS amplifiers built-in offset
voltage. This offset voltage directly determines the active
current limit value. With the I
SET
 pin open, the voltage at
the I
SET
 pin is determined by a positive temperature co-
efficient reference. This voltage is set to 0.618V at room
temperature which corresponds to a 5.6A current limit at
room temperature.
An external resistor placed between the I
SET
 pin and ground
forms a resistive divider with the internal 20k sourcing
resistor. The divider acts to lower the voltage at the I
SET
 
pin and therefore lower the current limit threshold. The
overall current limit threshold precision is reduced to
?2% when using a 20k resistor to halve the threshold.
Using a switch (connected to ground) in series with this
external resistor allows the active current limit to change
only when the switch is closed. This feature can be used
when the start-up current exceeds the typical maximum
load current.
Monitor MOSFET Temperature
The voltage at the I
SET
 pin increases linearly with increas-
ing temperature. The temperature profile of the I
SET
 pin is
shown in the Typical Performance Characteristics section.
Using a comparator or ADC to measure the I
SET
 voltage
provides an indicator of the MOSFET temperature.
There is an overtemperature circuit in the LTC4232 that
monitors an internal voltage similar to the I
SET
 pin voltage.
When the die temperature exceeds 145癈 the circuit turns
off the MOSFET until the temperature drops to 125癈.
Monitor MOSFET Current
The current in the MOSFET passes through a sense resis-
tor. The voltage on the sense resistor is converted to a
current that is sourced out of the I
MON
 pin. The gain of
I
SENSE
 amplifier is 20礎/A referenced from the MOSFET
current. This output current can be converted to a voltage
using an external resistor to drive a comparator or ADC.
The voltage compliance for the I
MON
 pin is from 0V to
INTV
CC
  0.7V.
A microcontroller with a built-in comparator can build a
simple integrating single-slope ADC by resetting a capaci-
tor that is charged with this current. When the capacitor
voltage trips the comparator and the capacitor is reset, a
timer is started. The time between resets will indicate the
MOSFET current.
Monitor OV and UV Faults
Protecting the load from an overvoltage condition is the
main function of the OV pin. In Figure 1 an external resis-
tive divider (driving the OV pin) connects to a comparator
to turn off the MOSFET when the V
DD
 voltage exceeds
15.2V. If the V
DD
 pin subsequently falls back below 14.9V,
the switch will be allowed to turn on immediately. In the
LTC4232 the OV pin threshold is 1.235V when rising, and
1.215V when falling out of overvoltage.
The UV pin functions as an undervoltage protection pin
or as an ON pin. In the Figure 1 application the MOSFET
turns off when V
DD
 falls below 9.23V. If the V
DD
 pin sub-
sequently rises above 9.88V for 100ms, the switch will
be allowed to turn on again. The LTC4232 UV turn-on/off
thresholds are 1.235V (rising) and 1.155V (falling).
In the cases of an undervoltage or overvoltage the MOSFET
turns off and there is indication on the PG status pin. When
the overvoltage is removed the MOSFETs gate ramps up
immediately at the rate determined by the INRUSH block.
Figure 4. Short-Circuit Waveform
V
GATE
10V/DIV
I
OUT
2A/DIV
V
OUT
10V/DIV
TIMER
2V/DIV
1ms/DIV
4232 F04
相关PDF资料
PDF描述
MAX6471TA25AD3+T IC REG LDO 2.5V/ADJ .3A 8-TDFN
GMM43DSEI CONN EDGECARD 86POS .156 EYELET
FSDM07652REWDTU IC SWIT PWM GREEN CM HV TO220F
TAP335K016GSB CAP TANT 3.3UF 16V 10% RADIAL
MAX6469TA33AD3+T IC REG LDO 3.3V/ADJ .3A 8-TDFN
相关代理商/技术参数
参数描述
LTC4232IDHC#PBF 功能描述:IC CTLR HOT SWAP 5A 16-DFN RoHS:是 类别:集成电路 (IC) >> PMIC - 热交换 系列:- 产品培训模块:Lead (SnPb) Finish for COTS Obsolescence Mitigation Program 标准包装:119 系列:- 类型:热交换控制器 应用:通用型,PCI Express? 内部开关:无 电流限制:- 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:80-TQFP 供应商设备封装:80-TQFP(12x12) 包装:托盘 产品目录页面:1423 (CN2011-ZH PDF)
LTC4232IDHC#TRPBF 功能描述:IC CTLR HOT SWAP 5A 16-DFN RoHS:是 类别:集成电路 (IC) >> PMIC - 热交换 系列:- 产品培训模块:Lead (SnPb) Finish for COTS Obsolescence Mitigation Program 标准包装:119 系列:- 类型:热交换控制器 应用:通用型,PCI Express? 内部开关:无 电流限制:- 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:80-TQFP 供应商设备封装:80-TQFP(12x12) 包装:托盘 产品目录页面:1423 (CN2011-ZH PDF)
LTC4240 制造商:LINER 制造商全称:Linear Technology 功能描述:CompactPCI Hot Swap Controller with I2C Compatible Interface
LTC4240CGN 功能描述:IC CTRLR HOTSWAP CPCI I2C 28SSOP RoHS:否 类别:集成电路 (IC) >> PMIC - 热交换 系列:- 产品培训模块:Lead (SnPb) Finish for COTS Obsolescence Mitigation Program 标准包装:119 系列:- 类型:热交换控制器 应用:通用型,PCI Express? 内部开关:无 电流限制:- 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:80-TQFP 供应商设备封装:80-TQFP(12x12) 包装:托盘 产品目录页面:1423 (CN2011-ZH PDF)
LTC4240CGN#PBF 功能描述:IC CTLR HOT SWAP CPCI I2C 28SSOP RoHS:是 类别:集成电路 (IC) >> PMIC - 热交换 系列:- 产品培训模块:Lead (SnPb) Finish for COTS Obsolescence Mitigation Program 标准包装:119 系列:- 类型:热交换控制器 应用:通用型,PCI Express? 内部开关:无 电流限制:- 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:80-TQFP 供应商设备封装:80-TQFP(12x12) 包装:托盘 产品目录页面:1423 (CN2011-ZH PDF)