参数资料
型号: ISL6141CBZA-T
厂商: INTERSIL CORP
元件分类: 电源管理
英文描述: Negative Voltage Hot Plug Controller
中文描述: 1-CHANNEL POWER SUPPLY SUPPORT CKT, PDSO8
封装: LEAD FREE, PLASTIC, MS-012AA, SOIC-8
文件页数: 13/19页
文件大小: 428K
代理商: ISL6141CBZA-T
13
Inrush Current Control
The primary function of the ISL6141 hot plug controller is to
control the inrush current. When a board is plugged into a
live backplane, the input capacitors of the board’s power
supply circuit can produce large current transients as they
charge up. This can cause glitches on the system power
supply (which can affect other boards!), as well as possibly
cause some permanent damage to the power supply.
The key to allowing boards to be inserted into a live
backplane is to turn on the power to the board in a controlled
manner, usually by limiting the current allowed to flow
through a FET switch, until the input capacitors are fully
charged. At that point, the FET is fully on, for the smallest
voltage drop across it. Figure 25 below illustrates the typical
inrush current response resulting from a hot insertion for the
following conditions:
V
EE
= -48V, Rsense = 0.02
(2.5A current limit)
C1 = 150nF, C2 = 3.3nF, R3 = 18k
I
Inrush
= 50
μ
A (100
μ
F/3.3nF) = 1.5A
C
L
= 100uF, R
L
= 150
(48V/150
= 320mA)
After the contact bounce subsides the UVLO and UV criteria
are quickly met and the GATE begins to ramp up. As the
GATE reaches approximately 4V with respect to the source,
the FET begins to turn on allowing current to charge the load
capacitor. As the drain to source voltage begins to drop, the
feedback network of C2 and R3 hold the GATE constant, in
this case limiting the current to approximately 1.3A. When
the DRAIN voltage completes its ramp down the load current
remains constant at 320mA as the GATE voltage increases
to its final value.
Electronic Circuit Breaker/Current Limit
The ISL6141/51 features programmable current limiting with a
fixed 600
μ
s time-out period to protect against excessive
supply or fault currents. The IntelliTrip
TM
electronic circuit
breaker is capable of detecting both hard faults, and less
severe Over-Current conditions.
The Over-Current trip point is determined by R1 (Eq. #3) also
referred to as Rsense. When the voltage across this resistor
exceeds 50mV, the current limit regulator will turn on, and the
GATE will be pulled lower (to ~4V) to regulate current through
the FET at 50mV/Rsense. If the fault persists and current
limiting exceeds the 600
μ
s time-out period, the FET will be
turned off by discharging the GATE pin to V
EE
. This will
enable the Over-Current latch and the PWRGD/PWRGD
output will transition to the inactive state to indicate power is
no longer good. To clear the latch and initiate a normal power-
up sequence, the user must either power down the system
(below the UVLO voltage), or toggle the UV pin below and
above its threshold (usually with an external transistor). Figure
26 below shows the Over-Current shut down and current
limiting response for a 10
short to ground on the output. With
a 10
short and a -48V supply, the initial fault current is
approximately 4.8A, producing a voltage drop across the
0.02
sense resistor of 95mV, roughly two times the Over-
Current threshold of 50mV. This enables the 600
μ
s timer and
the GATE is quickly pulled low to limit the current to 2.5A
(50mV/Rsense). The fault condition persists for the duration of
the time-out period and the GATE is latched off in about
670
μ
s. There is a short filter (3
μ
s nominal) on the comparator,
so current transients shorter than this will be ignored. Longer
transients will initiate the GATE pull down, current limiting, and
the timer. If the fault current goes away before the time-out
period expires the device will exit the current limiting mode
and resume normal operation.
FIGURE 25. INRUSH CURRENT LIMITING FOR A HOT
INSERTION
FIGURE 26. CURRENT LIMITING AND TIMEOUT
ISL6141, ISL6151
相关PDF资料
PDF描述
ISL6151 Octal D-Type Transparent Latches With 3-State Outputs 20-SOIC -40 to 85
ISL6151CBZA Negative Voltage Hot Plug Controller
ISL6151CBZA-T Negative Voltage Hot Plug Controller
ISL6141CB-T Negative Voltage Hot Plug Controller
ISL6151CB-T Negative Voltage Hot Plug Controller
相关代理商/技术参数
参数描述
ISL6141IB 功能描述:IC CTRLR HOT PLUG NEG VOLT 8SOIC RoHS:否 类别:集成电路 (IC) >> PMIC - 热交换 系列:- 产品培训模块:Obsolescence Mitigation Program 标准包装:100 系列:- 类型:热插拔开关 应用:通用 内部开关:是 电流限制:可调 电源电压:9 V ~ 13.2 V 工作温度:-40°C ~ 150°C 安装类型:表面贴装 封装/外壳:10-WFDFN 裸露焊盘 供应商设备封装:10-TDFN-EP(3x3) 包装:管件
ISL6141IB-T 功能描述:IC CTRLR HOT PLUG NEG VOLT 8SOIC RoHS:否 类别:集成电路 (IC) >> PMIC - 热交换 系列:- 产品培训模块:Obsolescence Mitigation Program 标准包装:100 系列:- 类型:热插拔开关 应用:通用 内部开关:是 电流限制:可调 电源电压:9 V ~ 13.2 V 工作温度:-40°C ~ 150°C 安装类型:表面贴装 封装/外壳:10-WFDFN 裸露焊盘 供应商设备封装:10-TDFN-EP(3x3) 包装:管件
ISL6141IBZA 功能描述:IC CTRLR HOT PLUG NEG VOLT 8SOIC RoHS:是 类别:集成电路 (IC) >> PMIC - 热交换 系列:- 产品培训模块:Obsolescence Mitigation Program 标准包装:100 系列:- 类型:热插拔开关 应用:通用 内部开关:是 电流限制:可调 电源电压:9 V ~ 13.2 V 工作温度:-40°C ~ 150°C 安装类型:表面贴装 封装/外壳:10-WFDFN 裸露焊盘 供应商设备封装:10-TDFN-EP(3x3) 包装:管件
ISL6141IBZA-T 功能描述:IC CTRLR HOT PLUG NEG VOLT 8SOIC RoHS:是 类别:集成电路 (IC) >> PMIC - 热交换 系列:- 产品培训模块:Obsolescence Mitigation Program 标准包装:100 系列:- 类型:热插拔开关 应用:通用 内部开关:是 电流限制:可调 电源电压:9 V ~ 13.2 V 工作温度:-40°C ~ 150°C 安装类型:表面贴装 封装/外壳:10-WFDFN 裸露焊盘 供应商设备封装:10-TDFN-EP(3x3) 包装:管件
ISL6142 制造商:INTERSIL 制造商全称:Intersil Corporation 功能描述:Negative Voltage Hot Plug Controller