- 您现在的位置：买卖IC网 > PDF目录44988 > LTC1643HCGN#PBF (LINEAR TECHNOLOGY CORP) 4-CHANNEL POWER SUPPLY SUPPORT CKT, PDSO16 PDF资料下载
参数资料
| 型号： | LTC1643HCGN#PBF |
| 厂商： | LINEAR TECHNOLOGY CORP |
| 元件分类： | 电源管理 |
| 英文描述： | 4-CHANNEL POWER SUPPLY SUPPORT CKT, PDSO16 |
| 封装： | 0.150 INCH, PLASTIC, SSOP-16 |
| 文件页数： | 16/16页 |
| 文件大小： | 278K |
| 代理商： | LTC1643HCGN#PBF |
9
LTC1643L/LTC1643L-1/LTC1643H
LTC1643 FEATURE SUMMARY
1. Allows safe board insertion and removal from either a
motherboard (LTC1643H) or CompactPCI board
(LTC1643L/LTC1643L-1).
2. Controls all four PCI supplies: –12V, 12V, 3.3V and 5V.
3. Programmable foldback current limit: a programmable
analog current limit with a value that depends on the
output voltage. If the output is shorted to ground, the
current limit drops to keep power dissipation and
supply glitches to a minimum.
4. Programmable circuit breaker: if a supply remains in
current limit too long, the circuit breaker will trip, the
supplies will be turned off and the FAULT pin pulled low.
5. Current limit power-up: the supplies are allowed to
power up in current limit. Allows the chip to power up
boards with widely varying capacitive loads without
tripping the circuit breaker. The maximum allowable
power-up time is programmable using the TIMER pin.
6. –12V and 12V power switches on chip.
7. Power good output: monitors the voltage status of the
four supply voltages, except the LTC1643L-1 which
only monitors 3VOUT and 5VOUT.
8. Space saving 16-pin SSOP package.
PCI Power Requirements
PCI systems usually require four power rails: 5V, 3.3V,
12V and –12V. Systems implementing the 3.3V signaling
environment are usually required to provide all four rails in
every system. Systems implementing the 5V signaling
environment may either ship the 3.3V supply with the
system or provide a means to add it afterward. The
tolerance of the supplies as measured at the components
on the plug-in card is summarized in Table 1.
APPLICATIONS INFORMATION
WU
U
Some
±12V supplies in CompactPCI applications are not
well regulated and can violate the tolerance specification.
For these applications, the LTC1643L-1 should be used
because the PWRGD signal does not depend on
±12V
outputs.
Power-Up Sequence
The power supplies are controlled by placing external
N-channel pass transistors in the 3.3V and 5V power
paths, and internal pass transistors for the 12V and –12V
power paths (Figure 1).
Resistors R1 and R2 provide current fault detection and
R7 and C1 provide current control loop compensation.
Resistors R5 and R6 prevent high frequency oscillations
in Q1 and Q2.
When the ON pin (Pin 5) is pulled high, the pass transistors
are allowed to turn on and a 20
A current source is
connected to the TIMER pin (Pin 4) (Figure 2).
The current in each pass transistor increases until it
reaches the current limit for each supply. Each supply is
then allowed to power up at the rate dv/dt = 50
A/C1 or as
determined by the current limit and the load capacitance
whichever is slower. Current limit faults are ignored while
the TIMER pin (Pin 4) voltage is ramping up and is less
than 0.9V below 12VIN (Pin 1). Once all four supply
voltages are within tolerance, the PWRGD pin (Pin 7) will
pull low.
Power-Down Sequence
When the ON (Pin 5) is pulled low, 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 4) is immediately pulled low.
The GATE pin (Pin 11) is pulled down by a 200
A current
source to prevent the load currents on the 3.3V and 5V
supplies from going to zero instantaneously and glitching
the power supply voltages. When any of the output
voltages dip below its threshold, the PWRGD pin (Pin 7)
pulls high.
Table 1. PCI Power Supply Requirements
CAPACITIVE
SUPPLY
TOLERANCE
LOAD
5V
±5%
< 3000
F
3.3V
±0.3V
< 3000
F
12V
±5%
< 500
F
– 12V
–12V
±10%
< 120
F
相关PDF资料 |
PDF描述 |
|---|---|
| LTC1643LCGN#TR | 4-CHANNEL POWER SUPPLY SUPPORT CKT, PDSO16 |
| LTC1728HS5-5 | 3-CHANNEL POWER SUPPLY SUPPORT CKT, PDSO5 |
| LTC1729CS8-8.4#TR | 1-CHANNEL POWER SUPPLY SUPPORT CKT, PDSO8 |
| LTC1772BIS6#PBF | 1 A SWITCHING CONTROLLER, 650 kHz SWITCHING FREQ-MAX, PDSO6 |
| LTC1871EMS#PBF-1 | SWITCHING CONTROLLER, 1000 kHz SWITCHING FREQ-MAX, PDSO10 |
相关代理商/技术参数 |
参数描述 |
|---|---|
| LTC1643L-1CGN | 制造商:Linear Technology 功能描述: |
| LTC1643LCGN | 制造商:Linear Technology 功能描述: 制造商:Linear Technology 功能描述:POWER CONTROL/MANAGEMENT, 16 Pin, Plastic, SSOP |
| LTC1643LCGN#PBF | 制造商:Linear Technology 功能描述:Hot Swap Controller 16-Pin SSOP N |
| LTC1644CGN | 功能描述:IC CONTROLLER HOT SWAP 20-SSOP 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 |
| LTC1644CGN#PBF | 功能描述:IC CONTROLLER HOT SWAP 20-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) |
发布紧急采购，3分钟左右您将得到回复。