
LTC4257CS8#PBF
ActiveIEEE 802.3AF PD POWER OVER ETHERNET INTERFACE CONTROLLER
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LTC4257CS8#PBF
ActiveIEEE 802.3AF PD POWER OVER ETHERNET INTERFACE CONTROLLER
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Technical Specifications
Parameters and characteristics for this part
| Specification | LTC4257CS8#PBF |
|---|---|
| Auxiliary Sense | False |
| Current - Supply | 3 mA |
| Internal Switch(s) | True |
| Mounting Type | Surface Mount |
| Number of Channels | 1 |
| Operating Temperature [Max] | 70 °C |
| Operating Temperature [Min] | 0 °C |
| Package / Case | 8-SOIC |
| Package / Case [x] | 0.154 in |
| Package / Case [y] | 3.9 mm |
| Power - Max [Max] | 12.95 W |
| Standards | 802.3af (PoE) |
| Supplier Device Package | 8-SO |
| Voltage - Supply [Max] | 57 V |
LTC4257-1 Series
IEEE 802.3af PD Power over Ethernet Interface Controller with Dual Current Limit
| Part | Embedded | Function | Type | Contents | Supplied Contents | Utilized IC / Part | Auxiliary Sense | Internal Switch(s) | Mounting Type | Operating Temperature [Max] | Operating Temperature [Min] | Number of Channels | Power - Max [Max] | Current - Supply | Standards | Voltage - Supply [Max] | Package / Case | Package / Case [y] | Package / Case [x] | Supplier Device Package |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Analog Devices | Power Over Ethernet (POE) | Power Management | Board(s) | Board(s) | LTC3825 LTC4257-1 | |||||||||||||||
Analog Devices | Surface Mount | 85 °C | -40 °C | 1 | 12.95 W | 3 mA | 802.3af (PoE) | 57 V | 8-SOIC | 3.9 mm | 0.154 in | 8-SO | ||||||||
Analog Devices | Surface Mount | 70 °C | 0 °C | 1 | 12.95 W | 3 mA | 802.3af (PoE) | 57 V | 8-SOIC | 3.9 mm | 0.154 in | 8-SO | ||||||||
Analog Devices | ||||||||||||||||||||
Analog Devices | Surface Mount | 85 °C | -40 °C | 1 | 12.95 W | 3 mA | 802.3af (PoE) | 57 V | 8-WFDFN Exposed Pad | 8-DFN (3x3) | ||||||||||
Analog Devices | Surface Mount | 70 °C | 0 °C | 1 | 12.95 W | 3 mA | 802.3af (PoE) | 57 V | 8-WFDFN Exposed Pad | 8-DFN (3x3) | ||||||||||
Analog Devices | Surface Mount | 85 °C | -40 °C | 1 | 12.95 W | 3 mA | 802.3af (PoE) | 57 V | 8-SOIC | 3.9 mm | 0.154 in | 8-SO | ||||||||
Analog Devices | Surface Mount | 70 °C | 0 °C | 1 | 12.95 W | 3 mA | 802.3af (PoE) | 57 V | 8-SOIC | 3.9 mm | 0.154 in | 8-SO | ||||||||
Analog Devices | Surface Mount | 85 °C | -40 °C | 1 | 12.95 W | 3 mA | 802.3af (PoE) | 57 V | 8-WFDFN Exposed Pad | 8-DFN (3x3) | ||||||||||
Analog Devices | Surface Mount | 85 °C | -40 °C | 1 | 12.95 W | 3 mA | 802.3af (PoE) | 57 V | 8-SOIC | 3.9 mm | 0.154 in | 8-SO |
Pricing
Prices provided here are for design reference only. For realtime values and availability, please visit the distributors directly
| Distributor | Package | Quantity | $ | |
|---|---|---|---|---|
| Digikey | Tube | 1 | $ 4.48 | |
| 10 | $ 2.97 | |||
| 25 | $ 2.58 | |||
| 100 | $ 2.14 | |||
| 250 | $ 1.92 | |||
| 500 | $ 1.79 | |||
| 1000 | $ 1.68 | |||
| 2500 | $ 1.57 | |||
| 5000 | $ 1.50 | |||
Description
General part information
LTC4257-1 Series
The LTC4257-1 provides complete signature and power interface functions for a device operating in an IEEE 802.3af Power over Ethernet (PoE) system. The LTC4257-1 simplifies Powered Device (PD) design by incorporating the 25k signature resistor, classification current source, input current limit, undervoltage lockout, thermal overload protection, signature disable and power good signalling, all in a single 8-pin package. The LTC4257-1 includes a precision, dual level current limit circuit. This allows it to charge large load capacitors and interface with legacy Power over Ethernet systems while maintaining compatibility with the current IEEE 802.3af specification. By incorporating a high voltage power MOSFET onboard, the LTC4257-1 provides the system designer with reduced cost while also saving board space.The LTC4257-1 can interface directly with a variety of ADI DC/DC converter products to provide a cost effective power solution for IP phones, wireless access points and other PDs. Analog Devices also provides network power controllers for Power Sourcing Equipment (PSE) applications.The LTC4257-1 is available in the 8-pin SO and low profile (3mm x 3mm) DFN packages.ApplicationsIP Phone Power ManagementWireless Access PointsTelecom Power Control
Documents
Technical documentation and resources