参数资料
型号: LTC1645CS#TRPBF
厂商: Linear Technology
文件页数: 15/24页
文件大小: 329K
描述: IC CTRLR SEQ HOTSWAP DUAL 14SOIC
标准包装: 2,500
类型: 热交换控制器
应用: 通用
内部开关:
电源电压: 1.2 V ~ 12 V
工作温度: 0°C ~ 70°C
安装类型: 表面贴装
封装/外壳: 14-SOIC(0.154",3.90mm 宽)
供应商设备封装: 14-SOIC
包装: 带卷 (TR)
15
LTC1645
1645fa
V
IN2
5V/DIV
V
IN1
5V/DIV
V
OUT2
5V/DIV
V
OUT1
5V/DIV
TIMER
2V/DIV
RESET
5V/DIV
Figure 16. Ramping 3.3V and 2.5V Up and Down Together
APPLICATIO S I FOR ATIO
U
U
U
This circuit guarantees that: (1) V
OUT1
  never exceeds
V
OUT2
 by more than 1.2V, and (2) V
OUT2
 is never greater
than V
OUT1
 by more than 0.4V. On power-up, V
OUT1
 and
V
OUT2
 ramp up together. On power-down, the LTC1645
turns off Q1 and Q2 simultaneously. Charge remains
stored on C
LOAD1
 and C
LOAD2
 and the output voltages will
vary depending on the loads. D1 and D2 turn on at H1V
(H0.5V each), ensuring condition 1 is satisfied, while D3
prevents violations of condition 2. Different diodes may be
necessary for different output voltage configurations.
Barring an overvoltage condition at the input(s), the only
time these diodes might conduct current is during a
power-down event, and then only to discharge C
LOAD1
 or
C
LOAD2
. In the case of an input overvoltage condition that
causes excess current to flow, the circuit breaker will trip
if the current limit level is set appropriately.
Figure 17 shows an application circuit where V
OUT1
ramps up before V
OUT2
. V
OUT1
 is initially discharged and
D1 is reverse-biased, thus the voltage at the ON pin is
determined only by V
CC1
 through the resistor divider R1
and R2. The voltage at the ON pin exceeds 0.8V if V
CC1
 is
above 4.6V and V
OUT1
 begins to ramp up after a timing
cycle. As V
OUT1
 ramps up, D1 becomes forward-biased
and pulls the ON pin above 2V when V
OUT1
 H 4.5V. This
turns on GATE2 and V
OUT2
 ramps up. The FB comparator
monitors V
OUT2
, and the spare comparator monitors
V
OUT1
 with R
HYST
 creating H50mV of hysteresis.
Power Supply Multiplexer
Using back-to-back FETs, the LTC1645 can Hot Swap two
supplies to the same output, automatically selecting the
primary supply if present or the secondary supply if the
primary supply is not available. Referring to Figure 18, a
diode-or circuit provides power to the LTC1645 if either
supply is up. Schottky diodes are used to prevent the
voltage at V
CC1
 from approaching the undervoltage lock-
out threshold. This application assumes that if a supply is
not present, the supply input is floating.
If only the 3.3V supply is present, the voltage at the COMP
+
pin is below the trip point and COMPOUT pulls the base of
Q3 low, allowing the GATE1 pin to ramp up normally. The
voltage at the ON pin exceeds 0.8V if the 3.3V supply is
greater than 3V, ramping up GATE1 and turning on Q1A and
Q1B. The ON pin does not exceed 2V (unless the 3.3V supply
exceeds 7.5V!), keeping GATE2 low and Q2A and Q2B off.
If only the 5V supply is present or if both supplies are
present, the COMP
+
 pin is above 1.238V and COMPOUT
allows the base of Q3 to be pulled high by R2. This turns
Q3 on, keeping GATE1 low and Q1A and Q1B off. The
voltage at the ON pin is pulled above 2V by R1 and GATE2
turns Q2A and Q2B on.
相关PDF资料
PDF描述
VI-2WW-CY-F3 CONVERTER MOD DC/DC 5.5V 50W
TAP105M035FCS CAP TANT 1UF 35V 20% RADIAL
TIM476M025P0Z CAP TANT 47UF 25V 20% RADIAL
VI-27V-CY-F2 CONVERTER MOD DC/DC 5.8V 50W
EPM7192SQI160-10N IC MAX 7000 CPLD 192 160-PQFP
相关代理商/技术参数
参数描述
LTC1645IS 功能描述:IC CTRLR SEQ HOTSWAP DUAL 14SOIC 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
LTC1645IS#PBF 功能描述:IC CTLR HOT SWAP SEQ DUAL 14SOIC 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
LTC1645IS#TR 功能描述:IC CTRLR SEQ HOTSWAP DUAL 14SOIC 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
LTC1645IS#TRPBF 功能描述:IC CTRLR SEQ HOTSWAP DUAL 14SOIC 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
LTC1645IS8 功能描述:IC CTRLR SEQ HOTSWAP DUAL 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