LTC4257
1
4257fb
The LTC
?/DIV>
4257 provides complete signature and power
interface functions for a device operating in an IEEE
802.3af Power over Ethernet (PoE) system. The LTC4257
simplifies Powered Device (PD) design by incorporating
the 25k signature resistor, the classification current source,
input current limit with thermal foldback, undervoltage
lockout and power good signalling, all in a single 8-pin
package. By incorporating a high voltage power MOSFET
onboard, the LTC4257 provides the system designer with
reduced cost while also saving board space.
The LTC4257 can interface directly with a variety of Linear
Technology DC/DC converter products to provide a cost
effective power solution for IP phones, wireless access
points and other PDs. Linear Technology also provides
solutions for Power Sourcing Equipment (PSE) applica-
tions with quad network power controllers.
The LTC4257 is available in the 8-pin SO and low profile
(3mm ?3mm) DFN packages.
?/DIV>
IP Phone Power Management
?/DIV>
Wireless Access Points
?/DIV>
Telecom Power Control
, LTC and LT are registered trademarks of Linear Technology Corporation.
?/DIV>
Complete Power Interface Port for IEEE 802.3af
?/DIV>
Powered Devices (PDs)
?/DIV>
Onboard 100V, 400mA Power MOSFET
?/DIV>
Precision Input Current Limit
?/DIV>
Onboard 25k Signature Resistor
?/DIV>
Programmable Classification Current (Class 0-4)
?/DIV>
Undervoltage Lockout
?/DIV>
Smart Thermal Protection
?/DIV>
Power Good Signal
?/DIV>
Available in 8-Pin SO and Low Profile (3mm ?3mm)
DFN Packages
IEEE 802.3af PD
Power over Ethernet
Interface Controller
GND
R
CLASS
R
CLASS
SMAJ58A
0.1礔
PWRGD
LTC4257
V
IN
SHDN
5礔
MIN
100k
3.3V
TO LOGIC
RTN
SWITCHING
POWER SUPPLY
V
IN
V
OUT
48V FROM
POWER SOURCING
EQUIPMENT
(PSE)
4257 TA01
+
+
DF01SA
~
~
+
Powered Device (PD)
5ms/DIV
V
IN
50V/DIV
V
OUT
20V/DIV
I
IN
200mA/DIV
PWRGD
50V/DIV
4225 TA02
LTC4257 Charging 300?/SPAN>F
Load Capacitor
FEATURES
DESCRIPTIO
APPLICATIO S
TYPICAL APPLICATIO
All other trademarks are the property of their respective owners.
发布紧急采购，3分钟左右您将得到回复。
相关PDF资料
LTC4260IUH#PBF
IC HOT SWAP CNTRL I2C 32-QFN
LTC4261IGN-2#PBF
IC CTRLR HOTSWAP W/ADC 28-SSOP
LTC4263IS#TRPBF
IC IEEE 803.2AF CNTRLR 14-SOIC
LTC4268IDKD-1#PBF
IC PD HIGH POWER W/CNTRL 32-DFN
LTC4274CUHF#PBF
IC CONTROLLER POE 38-QFN
LTC4280CUFD#PBF
IC CONTROLLER HOT SWAP QFN-24
LTC4300-1IMS8#TRPBF
IC HOTSWAP 2WIRE BUS BUFFR 8MSOP
LTC4300A-2IMS8#TRPBF
IC BUFFER BUS 2WR HOTSWAP 8-MSOP
相关代理商/技术参数
LTC4257CS8-#1TRPBF
制造商:LINEAR_TECH 功能描述:
LTC4257CS8#PBF
功能描述:IC CTRLR INTFACE PWR/ETHER 8SOIC 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
LTC4257CS8#TR
功能描述:IC CTRLR INTFACE PWR/ETHER 8SOIC RoHS:否 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
LTC4257CS8#TRPBF
功能描述:IC CTRLR INTFACE PWR/ETHER 8SOIC 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
LTC4257CS81
制造商:Linear Technology 功能描述:
LTC4257CS8-1
功能描述:IC CTRLR INTFACE PWR/ETHER 8SOIC RoHS:否 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
LTC4257CS81#PBF
制造商:Linear Technology 功能描述:
LTC4257CS8-1#PBF
功能描述:IC CTRLR INTFACE PWR/ETHER 8SOIC 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