Features: ` Integrated Power Interface Switch for IEEE 802.3af Powered Devices (PDs)
` Provides PD Detection Signature
` Provides PD Classification Signature (Class 0−4)
` Programmable Inrush Current Limit
` Internal 0.3- Low-Side FET
` Interfaces to DC/DC Soft-Start for DC/DC Enable
` Internal Thermal Protection Disconnects PD Load
` Minimal External Parts Count
` 8-Pin SOIC, 8-Pin TSSOP Packages
Application· VoIP Phones
· Internet Appliances
· Wireless LAN Access Points
· Bluetooth Access Points
Pinout
Specifications
| |
TPS2370 |
UNIT |
| Input voltage range, wrt VEE |
ILIM |
4 |
V |
| CLASS |
12 |
| DET, RTN, EN_DC, VDD |
68 |
| EN_DC (wrt RTN) |
5 |
| Operating junction temperature range, TJ |
−55 to 150 |
|
| Storage temperature, Tstg |
−65 to 150 |
|
| Lead temperature 1,6 mm (1/16 inch) from case for 10 seconds |
300 |
|
(2) Stresses beyond those listed under "absolute maximum ratings" may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated under "recommended operating conditions" is not implied. Exposure to absolute-maximum-rated conditions for extended periods may affect device reliability.
DescriptionActing as an interface between the power sourcing equipment (PSE) and the powered device (PD), the TPS2370 performs all detection, classification, inrush current limiting, and switch FET control that is necessary for compliance with the IEEE 802.3af Standard. An internal 0.3- FET provides maximum power delivery. As an additional feature, the TPS2370 interfaces with the enable/soft-start signal of a dc-to-dc converter, eliminating the need to have an accurate UVLO in the dc-to-dc converter.
At low input voltages (1.8 V to 10 V), the TPS2370 draws less than 12 A, allowing accurate sensing of the external 24.9-k discovery resistor. At input voltages between 15 V and 20 V, an external resistor sets the level of current to be drawn during classification mode.
TPS2370 is compatible with current as well as voltage measurement schemes for classification. Above 20-V input, the classification current is shut off, reducing internal power dissipation.
The TPS2370 drives an internal low-side FET for control of the return side of the power path. The internal FET is turned on when the input voltage reaches 40 V and above. When the input voltage decreases, the FET remains on until the input voltage drops to below 30 V.
TPS2370_1081745 Data Sheet
