Features
 Meets IEEE 802.3af/at Specifications
 Support 25W PoE Power Application
 100V, 0.48Ω Integrated Pass Switch
 180mA Inrush Current Limit
 Current Limit During Normal Operation
Between 720mA and 920mA
 Simplified Wall Adapter Interface
 Open Drain Type-2 PSE Indicator
 Current Limit and Fold-back
 Self-Driving Power Good Indicator
 Over Temperature Protection (OTP)
 DFN3x3-10 Package

Application
 VoIP Telephones
 Security Camera Systems
 Remote Internet Power
 Safety Backup Power

Description
The TMI7303B provides a complete interface for a
Powered Device (PD) with the IEEE 802.3af/at
standard in PoE system. The TMI7303B include
detection signature, classification signature and an
integrated isolation power switch with inrush
current control mode. It supports a 2-event
classification method as specified provide a signal
to indicate when probed by Type 2 power-sourcing
equipment (PSE). The devices detect the presence
of a wall adapter power-source connection and
allow a smooth switchover from the PoE power
source to the wall adapter. Thermal protection is
built in to accommodate both transient and/or
overload conditions, shutting the part down and
protecting the input source as well as the output
load depending on the particular fault conditions.
Inrush current limiting is included to slowly charge
the input capacitor without interruption due to die
heating, a problem encountered without the current
limit fold back feature.
The TMI7303B is available in a DFN3x3-10
package with exposed pad for low thermal
resistance.