参数资料
型号: LTC1646IGN#PBF
厂商: Linear Technology
文件页数: 11/20页
文件大小: 407K
描述: IC CNTRLR HOTSWAP PCIDUAL 16SSOP
标准包装: 100
类型: 热交换控制器
应用: CompactPCI?
内部开关:
电源电压: 3.3V,5V
工作温度: -40°C ~ 85°C
安装类型: 表面贴装
封装/外壳: 16-SSOP(0.154",3.90mm 宽)
供应商设备封装: 16-SSOP
包装: 管件
LTC1646
11
1646fa
Power-Down Sequence
When BD_SEL# is pulled high, a power-down sequence
begins (Figure 3).
Internal switches are connected to each of the output
supply voltage pins to discharge the bypass capacitors to
ground. The TIMER pin (Pin 2) is immediately pulled low.
The GATE pin (Pin 10) is pulled down by a 200礎 current
source to prevent the load currents on the 3.3V and 5V
supplies from going to zero instantaneously in order to
prevent glitching the power supply voltages. When either
of the output voltages dips below its threshold, HEALTHY#
pulls high and LOCAL_PCI_RST# will be asserted low.
Once the power-down sequence is complete, the CPCI
card may be removed from the slot. During extraction, the
precharge circuit will continue to bias the bus I/O pins at
1V until the 5V and 3.3V long connector pin connections
are separated.
Timer
During a power-up sequence, a 5礎 current source is
connected to the TIMER pin and current limit faults are
ignored until the voltage exceeds 1.25V. This feature
allows the chip to power up CPCI boards with widely
varying capacitive loads on the supplies. The power-up
time for either of the two outputs is given by:
t    XV
C
XV
I
I
ON
OUT
LOAD XVOUT
OUT
LIMIT XVOUT    LOAD XVOUT
(
)
"
"

(
)
(
)
(
)
= 2
(2)
Where XV
OUT
  = 5V
OUT
  or 3V
OUT
. For example, for
C
LOAD
(5V
OUT
) = 2000礔, I
LIMIT
 = 7A, and I
LOAD
 = 5A, the
5V
OUT
 turn-on time will be ~10ms. By substituting the
variables in Equation 2 with the appropriate values, the
turn-on time for the 3V
OUT
 output can also be calculated.
The timer period should be set longer than the maximum
supply turn-on time but short enough to not exceed the
maximum safe operating area of the pass transistor during
a short-circuit. The timer period for the LTC1646 is given
by:
t
C
V
A
TIMER
TIMER
=
?/DIV>
"  .
1 25
5
(3)
As a design aid, the timer period as a function of the timing
capacitor using standard values from 0.01礔 to 1礔 is
shown in Table 2.
20ms/DIV
GATE
10V/DIV
5V
OUT
3V
OUT
5V/DIV
TIMER
5V/DIV
BD_SEL#
5V/DIV
HEALTHY#
5V/DIV
LCL_PCI_RST#
5V/DIV
PRECHARGE
5V/DIV
1646 F02
GATE
10V/DIV
5V
OUT
3V
OUT
5V/DIV
TIMER
5V/DIV
BD_SEL#
5V/DIV
HEALTHY#
5V/DIV
CL_PCI_RST#
5V/DIV
PRECHARGE
5V/DIV
1  4   F
Figure 2. Normal Power-Up Sequence
Figure 3. Normal Power-Down Sequence
APPLICATIO S I FOR ATIO
U
U
U
相关PDF资料
PDF描述
VY2151K29Y5SS6TV0 CAP CER 150PF 300V 10% RADIAL
CENB1010A0603F01 POWER SUPPLY EXT 12W 6V @ 2A
T86C475M025EAAS CAP TANT 4.7UF 25V 20% 2312
VY2151K29Y5SS63V0 CAP CER 150PF 300V 10% RADIAL
VE-21V-EV-F3 CONVERTER MOD DC/DC 5.8V 150W
相关代理商/技术参数
参数描述
LTC1647-1CS8 功能描述:IC CONTROLLR HOTSWAP DUAL 8-SOIC 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
LTC1647-1CS8#PBF 功能描述:IC CTLR HOTSWAP DUAL 8-SOIC 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)
LTC1647-1CS8#TR 功能描述:IC CONTROLLER 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
LTC1647-1CS8#TRPBF 功能描述:IC CONTROLLR HOTSWAP DUAL 8-SOIC 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
LTC1647-1IS8 功能描述:IC CONTROLLER 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