1 Features
• Enhanced ESD ride-through capability
• Optimized for isolated converters
• Complete PoE interface
• Adapter ORing support
• 12-V adapter support
• Programmable frequency with synchronization
• Robust 100-V, 0.7-Ω hotswap MOSFET
• Small 14-Pin TSSOP package
• 15-kV and 8-kV system level ESD capable
• –40°C to 125°C junction temperature range
• Design procedure application note – SLVA305
• Adapter oring application note – SLVA306

2 Applications
• IEEE 802.3at compliant powered devices
• VoIP telephones
• Access points
• Security cameras

3 Description
The TPS23753A is a combined Power over Ethernet
(PoE) powered device (PD) interface and currentmode
DC-DC controller optimized specifically for
isolated converter designs. The PoE implementation
supports the IEEE 802.3at standard as a 13-W, type 1
PD. The requirements for an IEEE 802.3at type 1
device are a superset of IEEE 802.3-2008 (originally
IEEE 802.3af).
The TPS23753A supports a number of input-voltage
ORing options including highest voltage, external
adapter preference, and PoE preference.
The PoE interface features an external detection
signature pin that can also be used to disable the
internal hotswap MOSFET. This allows the PoE
function to be turned off. Classification can be
programmed to any of the defined types with a single
resistor.
The DC-DC controller features a bootstrap start-up
mechanism with an internal, switched current source.
This provides the advantages of cycling overload fault
protection without the constant power loss of a pullup
resistor.
The programmable oscillator may be synchronized to
a higher-frequency external timing reference. The
TPS23753A features improvements for uninterrupted
device operation through an ESD event.