- 您现在的位置：买卖IC网 > PDF目录11595 > LTC4267IGN#PBF (Linear Technology)IC POE 802.3AF INTERFACE 16SSOP PDF资料下载
参数资料
| 型号： | LTC4267IGN#PBF |
| 厂商： | Linear Technology |
| 文件页数： | 3/32页 |
| 文件大小： | 0K |
| 描述： | IC POE 802.3AF INTERFACE 16SSOP |
| 产品培训模块： | Power over Ethernet |
| 标准包装： | 100 |
| 控制器类型： | 以太网供电控制器（POE） |
| 接口： | IEEE 802.3af |
| 电流 - 电源： | 3mA |
| 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 |
| 产品目录页面： | 1338 (CN2011-ZH PDF) |
| 相关产品： | 732-2437-6-ND - TRANS FLYBACK POE 40UH SMD 732-2436-6-ND - TRANS FLYBACK POE 35UH SMD 732-2435-6-ND - TRANS FLYBACK POE 127UH SMD 732-2434-6-ND - TRANS FLYBACK POE 127UH SMD 732-2433-6-ND - TRANS FLYBACK POE 127UH SMD 732-2432-6-ND - TRANS FLYBACK POE 127UH SMD 732-2431-6-ND - TRANS FLYBACK POE 127UH SMD 732-2430-6-ND - TRANS FLYBACK POE 127UH SMD 732-2437-1-ND - TRANS FLYBACK POE 40UH SMD 732-2436-1-ND - TRANS FLYBACK POE 35UH SMD 更多... |
第1页第2页当前第3页第4页第5页第6页第7页第8页第9页第10页第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
LTC4267
11
4267fc
Series Diodes
The IEEE 802.3af-dened operating modes for a PD refer-
ence the input voltage at the RJ45 connector on the PD.
The PD must be able to accept power of either polarity
at each of its inputs, so it is common to install diode
bridges (Figure 2). The LTC4267 takes this into account
by compensating for these diode drops in the threshold
points for each range of operation. A similar adjustment
is made for the UVLO voltages.
Detection
During detection, the PSE will apply a voltage in the
range of – 2.8V to –10V on the cable and look for a 25kΩ
signature resistor. This identies the device at the end of
the cable as a PD. With the terminal voltage in this range,
the LTC4267 connects an internal 25kΩ resistor between
the VPORTP and VPORTN pins. This precision, temperature
compensated resistor presents the proper signature to
alert the PSE that a PD is present and desires power to be
applied. The internal low-leakage UVLO switch prevents
the switching regulator circuitry from affecting the detec-
tion signature.
The LTC4267 is designed to compensate for the voltage
and resistance effects of the IEEE required diode bridge.
The signature range extends below the IEEE range to ac-
commodate the voltage drop of the two diodes. The IEEE
specication requires the PSE to use a ΔV/ΔI measurement
technique to keep the DC offset of these diodes from af-
fecting the signature resistance measurement. However,
the diode resistance appears in series with the signature
resistor and must be included in the overall signature
resistance of the PD. The LTC4267 compensates for the
two series diodes in the signature path by offsetting the
resistance so that a PD built using the LTC4267 will meet
the IEEE specication.
In some applications it is necessary to control whether or
not the PD is detected. In this case, the 25kΩ signature
resistor can be enabled and disabled with the use of the
SIGDISA pin (Figure 3). Disabling the signature via the
SIGDISA pin will change the signature resistor to 9kΩ
(typical) which is an invalid signature per the IEEE 802.3af
specication. This invalid signature is present for PD input
voltages from –2.8V to –10V. If the input rises above –10V,
the signature resistor reverts to 25kΩ to minimize power
dissipation in the LTC4267. To disable the signature, tie
SIGDISA to VPORTP. Alternately, the SIGDISA pin can be
driven high with respect to VPORTN. When SIGDISA is high,
all functions of the PD interface are disabled.
APPLICATIO S I FOR ATIO
WU
UU
RX–
6
RX+
3
TX–
2
TX+
RJ45
T1
POWERED DEVICE (PD)
INTERFACE
AS DEFINED
BY IEEE 802.3af
4267 F02
1
7
8
5
4
SPARE–
SPARE+
TO PHY
BR2
BR1
VPORTP
8
4
D3
LTC4267
VPORTN
Figure 2. LTC4267 PD Front End Using
Diode Bridges on Main and Spare Inputs
相关PDF资料 |
PDF描述 |
|---|---|
| PIC12C508AT-04E/SN | IC MCU OTP 512X12 8SOIC |
| LTC1955EUH#PBF | IC INTERFACE DL SMART CARD 32QFN |
| PIC16LF1512-E/SP | IC MCU 8BIT 3.5KB FLASH 28-SPDIP |
| PIC16F1512-E/SP | IC MCU 8BIT 3.5KB FLASH 28-SPDIP |
| PIC16F1827T-I/SS | MCU PIC 8BIT 4K FLASH 20-SSOP |
相关代理商/技术参数 |
参数描述 |
|---|---|
| LTC4268-1 | 制造商:LINER 制造商全称:Linear Technology 功能描述:Quad IEEE 802.3at Power over Ethernet Controller |
| LTC4268-1_12 | 制造商:LINER 制造商全称:Linear Technology 功能描述:High Power PD With Synchronous No-Opto Flyback Controller |
| LTC4268CDKD-1 | 制造商:LINER 制造商全称:Linear Technology 功能描述:High Power PD with Synchronous NoOpto Flyback Controller |
| LTC4268CDKD-1#PBF | 功能描述:IC PD HIGH POWER W/CNTRL 32-DFN RoHS:是 类别:集成电路 (IC) >> PMIC - 热交换 系列:- 标准包装:50 系列:- 类型:热交换控制器 应用:-48V 远程电力系统，AdvancedTCA ? 系统，高可用性 内部开关:无 电流限制:可调 电源电压:11.5 V ~ 14.5 V 工作温度:-40°C ~ 85°C 安装类型:表面贴装 封装/外壳:10-TFSOP，10-MSOP（0.118"，3.00mm 宽） 供应商设备封装:10-MSOP 包装:管件 |
| LTC4268CDKD-1#TRPBF | 功能描述:IC PD HIGH POWER W/CNTRL 32-DFN RoHS:是 类别:集成电路 (IC) >> PMIC - 热交换 系列:- 标准包装:50 系列:- 类型:热交换控制器 应用:-48V 远程电力系统，AdvancedTCA ? 系统，高可用性 内部开关:无 电流限制:可调 电源电压:11.5 V ~ 14.5 V 工作温度:-40°C ~ 85°C 安装类型:表面贴装 封装/外壳:10-TFSOP，10-MSOP（0.118"，3.00mm 宽） 供应商设备封装:10-MSOP 包装:管件 |
发布紧急采购，3分钟左右您将得到回复。