Product Summary

The LTC4257CS8-1#TR provides complete signature and power interface functions for a device operating in an IEEE 802.3af Power over Ethernet (PoE) system. The LTC4257CS8-1#TR 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 LTC4257CS8-1#TR provides the system designer with reduced cost while also saving board space. The applications of the LTC4257CS8-1#TR are (1)IP phone power management; (2)wireless access points; (3)telecom power control.

Parametrics

LTC4257CS8-1#TR absolute maximum ratings: (1)VIN Voltage: 0.3V to -100V; (2)VOUT, PWRGD Voltage: VIN + 100V to VIN - 0.3V; (3)RCLASS Voltage: VIN + 7V to VIN - 0.3V; (4)PWRGD Current: 10mA; (5)RCLASS Current: 100mA; (6)Operating Ambient Temperature Range: 0°C to 70°C; (7)Storage Temperature Range; (8)S8 Package: -65°C to 150°C; (9)DD Package: -65°C to 125°C; (10)Lead Temperature (Soldering, 10 sec): 300°C.

Features

LTC4257CS8-1#TR features: (1)Complete Power Interface Port for IEEE 802.3af® Powered Devices (PDs); (2)Onboard 100V, 400mA Power MOSFET; (3)Precision Input Current Limit; (4)Onboard 25k Signature Resistor; (5)Programmable Classification Current (Class 0-4); (6)Undervoltage Lockout; (7)Smart Thermal Protection; (8)Power Good Signal; (9)Available in 8-Pin SO and Low Profile (3mm × 3mm)DFN Packages.

Diagrams

LTC4257CS8-1#TR pin connection

Image Part No Mfg Description Data Sheet Download Pricing
(USD)
Quantity
LTC4257CS8-1#TR
LTC4257CS8-1#TR


IC CTRLR INTFACE PWR/ETHER 8SOIC

Data Sheet

0-5000: $1.27
LTC4257CS8-1#TRPBF
LTC4257CS8-1#TRPBF


IC CTRLR INTFACE PWR/ETHER 8SOIC

Data Sheet

0-2500: $1.27