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参数资料
| 型号： | LTC4259CGW#PBF |
| 厂商： | LINEAR TECHNOLOGY CORP |
| 元件分类： | 电源管理 |
| 英文描述： | 4-CHANNEL POWER SUPPLY SUPPORT CKT, PDSO36 |
| 封装： | 0.300 INCH, PLASTIC, SSOP-36 |
| 文件页数： | 16/32页 |
| 文件大小： | 324K |
| 代理商： | LTC4259CGW#PBF |
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LTC4259
23
4259i
APPLICATIO S I FOR ATIO
WU
UU
disconnect itself is a more thorough test of the OSCIN
signal. When the OSCIN signal is either absent or cor-
rupted, powered channels with AC disconnect enabled
(and DC disconnect not enabled) will automatically dis-
connect of their own accord in time tDIS. After the LTC4259
is reset (by power on, Reset All bit or the RESET pin) the
Osc Fail bit is set. Once the Osc Fail bit is cleared, it will only
be set by an invalid signal on the OSCIN pin or another
reset.
SERIAL DIGITAL INTERFACE
The LTC4259 communicates with a host (master) using
the standard 2-wire interface as described in the SMBus
Specification Version 2.0 (available at http://smbus.org).
The SMBus is an extension of the I2C bus, and the
LTC4259 is also compatible with the I2C bus standard. The
Timing Diagrams show the timing relationship of the
signals on the bus. The two bus lines, SDA and SCL, must
be high when the bus is not in use. External pull-up
resistors or current sources, such as the LTC1694 SMBus
accelerator, are required on these lines. If the SDA and SCL
pull-ups are absent, not connected to the same positive
supply as the LTC4259’s VDD pin, or are not activated
when the power is applied to the LTC4259, it is possible for
the LTC4259 to see a START condition on the I2C bus. The
interrupt pin (INT) is only updated between I2C transac-
tions. Therefore if the LTC4259 sees a START condition
when it powers up because the SCL and SDA lines were left
floating, it will not assert an interrupt (pull INT low) until
it sees a STOP condition on the bus. In a typical application
the I2C bus will immediately have traffic and the LTC4259
will see a STOP so soon after power up that this momen-
tary condition will go unnoticed.
Isolating the Serial Digital Interface
IEEE 802.3af requires that network segments be electri-
cally isolated from the chassis ground of each network
interface device. However, the network segments are not
required to be isolated from each other provided that the
segments are connected to devices residing within a
single building on a single power distribution system.
For simple devices such as small powered Ethernet
switches, the requirement can be met by using an isolated
power supply to power the entire device. This implemen-
tation can only be used if the device has no electrically
conducting ports other than twisted-pair Ethernet. In this
case, the SDAIN and SDAOUT pins of the LTC4259 can be
connected together to act as a standard SDA pin.
If the device is part of a larger system, contains serial
ports, or must be referenced to protective ground for
some other reason, the Power over Ethernet subsystem
including the LTC4259s must be isolated from the rest of
the system. The LTC4259 includes separate pins (SDAIN
and SDAOUT) for the input and output functions of the
bidirectional data line. This eases the use of optocouplers
to isolate the data path between the LTC4259s and the
system controller. Figure 18 shows one possible imple-
mentation of an isolated interface. The SDAOUT pin of the
LTC4259 is designed to drive the inputs of an optocoupler
directly, but a standard I2C device typically cannot. U1 is
used to buffer I2C signals into the optocouplers from the
system controller side. Schmitt triggers must be used to
prevent extra edges on transitions of SDA and SCL.
Bus Addresses and Protocols
The LTC4259 is a read-write slave device. The master can
communicate with the LTC4259 using the Write Byte,
Read Byte and Receive Byte protocols. The LTC4259’s
primary serial bus address is (010A3A2A1A0)b, as desig-
nated by pins AD3-AD0. All LTC4259s also respond to the
address (0110000)b, allowing the host to write the same
command into all of the LTC4259s on a bus in a single
transaction. If the LTC4259 is asserting (pulling low) the
INT pin, it will also acknowledge the Alert Response
Address (0001100)b using the receive byte protocol.
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相关代理商/技术参数 |
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| LTC4260 | 制造商:LINER 制造商全称:Linear Technology 功能描述:UV, OV and Reverse Supply Protection Controller Low Operating Current: 125μA |
| LTC4260CGN | 制造商:Linear Technology 功能描述:Hot Swap Controller 1-CH 80V 24-Pin SSOP N |
| LTC4260CGN#PBF | 功能描述:IC CTLR HOT SWAP I2C 24-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) |
| LTC4260CGN#TR | 制造商:Linear Technology 功能描述:Hot Swap Controller 1-CH 80V 24-Pin SSOP N T/R |
| LTC4260CGN#TRPBF | 功能描述:IC HOT SWAP CNTRL I2C 24-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) |
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