LTC4257-1CS8

The LTC4257-1CS8 is one member of LTC4257-1 family. The LTC4257-1 provides complete signature and powerinterface functions for a device operating in an IEEE802.3af Power over Ethernet (PoE) system. The LTC4257-1simplifies Powered Device (PD) design by incorporatingthe 25k signature resistor, classification current source,input current limit, undervoltage lockout, thermal over-load protection, signature disable and power good signal-ling, all in a single 8-pin package.

Features of the LTC4257-1CS8 are:(1)Complete Power Interface Port for IEEE 802.3afPowered Devices (PDs); (2)Onboard 100V, 400mA Power MOSFET; (3)Precision Dual Level Current Limit; (4)Onboard 25k Signature Resistor with Disable; (5)Programmable Classification Current (Class 0-4); (6)Undervoltage Lockout; (7)Thermal Overload Protection; (8)Power Good Signal; (9)Available in 8-Pin SO and Low Profile (3mm * 3mm)DFN Packages.

The absolute maximum ratings of the LTC4257-1CS8 can be summarized as:(1)Vin  Voltage: 0.3V to 100V; (2)Vout, SIGDISA,PWRGD Voltage:Vin+ 100V to Vin0.3V; (3)Rclass Voltage:VIN + 7V to VIN 0.3V; (4)PWRGD Current:10mA; (5)Rclass Current: 100mA; (6)Operating Ambient Temperature Range:40°C to 85°C; (7)Storage Temperature Range: 65°C to 150°C; (8)Lead Temperature (Soldering, 10 sec):300°C. If you want to know more information such as the electrical characteristics about the LTC4257-1CS8, please download the datasheet in www.seekic.com or www.chinaicmart.com.