- 您现在的位置：买卖IC网 > PDF目录179918 > LTC4252A-2CMS#TRPBF (LINEAR TECHNOLOGY CORP) Negative Voltage Hot Swap Controllers; Package: MSOP; No of Pins: 10; Temperature Range: 0°C to +70°C PDF资料下载
参数资料
| 型号： | LTC4252A-2CMS#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: 10; Temperature Range: 0°C to +70°C |
| 中文描述： | 1-CHANNEL POWER SUPPLY SUPPORT CKT, PDSO10 |
| 封装： | LEAD FREE, PLASTIC, MSOP-10 |
| 文件页数： | 11/36页 |
| 文件大小： | 394K |
| 代理商： | LTC4252A-2CMS#TRPBF |
第1页第2页第3页第4页第5页第6页第7页第8页第9页第10页当前第11页第12页第13页第14页第15页第16页第17页第18页第19页第20页第21页第22页第23页第24页第25页第26页第27页第28页第29页第30页第31页第32页第33页第34页第35页第36页
LTC4252-1/LTC4252-2
LTC4252A-1/LTC4252A-2
19
425212fb
A low impedance short on one card may influence the
behavior of others sharing the same backplane. The initial
glitch and backplane sag as seen in Figure 6 Trace 1, can
rob charge from output capacitors on adjacent cards.
When the faulty card shuts down, current flows in to
refresh the capacitors. If LTC4252s are used by the other
cards, they respond by limiting the inrush current to a
value of 100mV/RS. If CT is sized correctly, the capacitors
will recharge long before CT times out.
POWER GOOD, PWRGD
PWRGD latches low if GATE charges up to within 2.8V of
VIN and DRAIN pulls below VDRNL during start-up. PWRGD
is reset in UVLO, in a UV condition or if CT charges up to
4V. An overvoltage condition has no effect on PWRGD
status. A 58
A current pulls this pin high during reset. Due
to voltage transients between the power module and
PWRGD, optoisolation is recommended. This pin pro-
vides sufficent drive for an optocoupler. Figure 19 shows
an alternative NPN configuration with a limiting base
resistor for the PWRGD interface. The module enable
input should have protection from the negative input
current.
MOSFET SELECTION
The external MOSFET switch must have adequate safe
operating area (SOA) to handle short-circuit conditions
until TIMER times out. These considerations take prece-
dence over DC current ratings. A MOSFET with adequate
SOA for a given application can always handle the required
current, but the opposite may not be true. Consult the
manufacturer’s MOSFET data sheet for safe operating area
and effective transient thermal impedance curves.
MOSFET selection is a 3-step process by assuming the
absense of a soft-start capacitor. First, RS is calculated and
then the time required to charge the load capacitance is de-
termined. This timing, along with the maximum short-cir-
cuit current and maximum input voltage defines an oper-
ating point that is checked against the MOSFET’s SOA curve.
To begin a design, first specify the required load current
and Ioad capacitance, IL and CL. The circuit breaker
current trip point (VCB/RS) should be set to accommodate
the maximum load current. Note that maximum input
current to a DC/DC converter is expected at VSUPPLY(MIN).
RS is given by:
R
V
I
S
CB MIN
LMAX
=
()
(8)
where VCB(MIN) = 40mV (45mV for LTC4252A) represents
the guaranteed minimum circuit breaker threshold.
During the initial charging process, the LTC4252 may
operate the MOSFET in current limit, forcing (VACL) be-
tween 80mV to 120mV (VACL is 54mV to 66mV for
LTC4252A) across RS. The minimum inrush current is
given by:
I
mV
R
INRUSH MIN
S
()=
80
(9)
Maximum short-circuit current limit is calculated using
the maximum VACL. This gives
I
mV
R
SHORTCIRCUIT MAX
S
()=
120
(10)
The TIMER capacitor CT must be selected based on the
slowest expected charging rate; otherwise TIMER might
time out before the load capacitor is fully charged. A value
for CT is calculated based on the maximum time it takes the
load capacitor to charge. That time is given by:
t
CV
I
CV
I
CL CHARGE
L
SUPPLY MAX
INRUSH MIN
()
==
(11)
The maximum current flowing in the DRAIN pin is given
by:
I
VV
R
DRN MAX
SUPPLY MAX
DRNCL
D
()
=
(12)
APPLICATIO S I FOR ATIO
WU
U
相关PDF资料 |
PDF描述 |
|---|---|
| LTC4252A-2IMS#PBF | Negative Voltage Hot Swap Controllers; Package: MSOP; No of Pins: 10; Temperature Range: -40°C to +85°C |
| LTC4252A-2IMS#TRPBF | Negative Voltage Hot Swap Controllers; Package: MSOP; No of Pins: 10; Temperature Range: -40°C to +85°C |
| LTC4252-2CMS8#PBF | Negative Voltage Hot Swap Controllers; Package: MSOP; No of Pins: 8; Temperature Range: 0°C to +70°C |
| LTC4252-2CMS8#TRPBF | Negative Voltage Hot Swap Controllers; Package: MSOP; No of Pins: 8; Temperature Range: 0°C to +70°C |
| LTC4252-2IMS8#PBF | Negative Voltage Hot Swap Controllers; Package: MSOP; No of Pins: 8; Temperature Range: -40°C to +85°C |
相关代理商/技术参数 |
参数描述 |
|---|---|
| LTC4252A-2IMS | 功能描述:IC CTRLR HOTSWAP NEG VOLT 10MSOP 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 |
| LTC4252A-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:- 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 |
| LTC4252A-2IMS#TR | 功能描述:IC CTRLR HOTSWAP NEG VOLT 10MSOP 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 |
| LTC4252A-2IMS#TRPBF | 功能描述:IC CNTRLR HOTSWAP NEGVOLT 10MSOP 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 |
| LTC4252A-2IMSPBF | 制造商:LINER 制造商全称:Linear Technology 功能描述:Negative Voltage Hot Swap Controllers |
发布紧急采购，3分钟左右您将得到回复。