参数资料
型号: LTC4261CUFD-2#PBF
厂商: LINEAR TECHNOLOGY CORP
元件分类: 电源管理
英文描述: Negative Voltage Hot Swap Controllers with ADC and I2C Monitoring; Package: QFN; No of Pins: 24; Temperature Range: 0°C to +70°C
中文描述: 1-CHANNEL POWER SUPPLY SUPPORT CKT, PQCC24
封装: 4 X 5 MM, LEAD FREE, PLASTIC, QFN-24
文件页数: 10/34页
文件大小: 357K
代理商: LTC4261CUFD-2#PBF
LTC4261/LTC4261-2
18
42612fc
Figure 6. Overcurrent Fault and Auto-Retry
In the case of a low impedance short circuit on the load
side or an input step during battery replacement, current
overshoot is inevitable. A fast SENSE comparator with a
threshold of 250mV detects the overshoot and immedi-
ately pulls GATE low. Once the SENSE voltage drops to
50mV, the current limit loop takes over and servos the
current as previously described. If the short-circuit con-
dition lasts longer than 530s, the FET is shut down and
the overcurrent fault is registered.
Inthecaseofaninputstep,afteraninternalclamppullsthe
RAMP pin down to 1.1V, the inrush control circuit takes
over and the current limit loop is disengaged before the
circuitbreakertimerexpires.Fromthispointon,thedevice
works as in the initial start-up: VOUT is ramped down at the
rate set by IRAMP and CR followed by GATE pull-up. The
power good signals on the PG and PGIO pins, the TMR
pin, and the SS pin are not interrupted through the input
step sequence. The waveform in Figure7 shows how the
LTC4261/LTC4261-2respondstoaninputstep.
Note that the current limit threshold should be set
sufficiently high to accommodate the sum of the load
current and the inrush current to avoid engagement of
the current limit loop in the event of an input step. The
maximum value of the inrush current is given by:
IINRUSH ≤ 0.8
45mV
RS
– ILOAD
where the 0.8 factor is used as a worst case margin com-
bined with the minumum threshold (45mV).
The active current limit circuit is compensated using the
capacitor CG with a series resistor RG (10W) connected
between GATE and VEE, as shown in Figure 1. The sug-
gested value for CG is 50nF. This value should work for
most pass transistors (Q1).
Overvoltage Fault
An overvoltage fault occurs when the OV pin rises above
its 1.77V threshold. This shuts off the pass transistor
immediately, sets the overvoltage present bit A0 and
the overvoltage fault bit B0, and pulls the SS pin down.
Note that the power good signals are not affected by the
overvoltage fault. If the OV pin subsequently falls back
below the threshold, the pass transistor will be allowed
to turn on again immediately (without delay) unless the
APPLICATIONS INFORMATION
TMR
SS
GATE
VOUT
SENSE
PG
PGIO
OC COOLING DELAY
PWRGD1
DELAY
4x
2x
VZ – 1.2V
1.77V
INRUSH
PWRGD2
DELAY
2x
50mV
530s
42612 F06
相关PDF资料
PDF描述
LTC4261CUFD-2#TRPBF Negative Voltage Hot Swap Controllers with ADC and I2C Monitoring; Package: QFN; No of Pins: 24; Temperature Range: 0°C to +70°C
LTC4261IGN#PBF Negative Voltage Hot Swap Controllers with ADC and I2C Monitoring; Package: SSOP; No of Pins: 28; Temperature Range: -40°C to +85°C
LTC4261IGN#TRPBF Negative Voltage Hot Swap Controllers with ADC and I2C Monitoring; Package: SSOP; No of Pins: 28; Temperature Range: -40°C to +85°C
LTC4263CDE#PBF Single IEEE 802.3af Compliant PSE Controller with Internal Switch; Package: DFN; No of Pins: 14; Temperature Range: 0°C to +70°C
LTE-4218 5 mm, 1 ELEMENT, INFRARED LED, 940 nm
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LTC4261IGN#PBF 功能描述:IC CTRLR HOTSWAP W/ADC 28-SSOP 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)
LTC4261IGN#TR 功能描述:IC CTRLR HOTSWAP W/ADC 28-SSOP 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)
LTC4261IGN#TRPBF 功能描述:IC CTRLR HOTSWAP W/ADC 28-SSOP 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)
LTC4261IGN-2 制造商:LINER 制造商全称:Linear Technology 功能描述:Negative Voltage Hot Swap Controllers with ADC and I2C Monitoring