• IEEE 802.3af/at Powered Device (PD) Controller
• Supports Up to 90W PDs
• Support All of the Following Standards:

-High Power Mode: 38.7W, 52.7W, 70W and 90W

-IEEE 802.3at 25.5W Compliant

-IEEE 802.3af up to 13W Compliant

• Superior Surge Protection (100V Absolute Maximum)
• Wide Junction Temperature Range (–40℃ to 125℃)
• Over Temperature Protection
• Integrated Signature Resistor
• External Hot Swap N-Channel MOSFET for Lowest Power Dissipation and Highest System Efficiency
• Configurable Aux Power Support as Low as 9V
• RoHS Compliant and Halogen Free
• Available in 3mm × 3mm DFN Package

The SY28902B is a power device (PD) controller with all the features needed to implement the IEEE802.3at/at protocol. It employs a high-power classification scheme, delivering 38.7W, 52.7W, 70W or 90W of power at the PD RJ45 connector. The SY28902B is fully compatible with IEEE 802.3af/at.

An internal charge-pump is used for enabling the use of external low RDS(ON) N-channel MOSFETs and increase the end-to-end power transmission efficiency. The SY28902B includes an integrated signature resistor, under-voltage lockout, a power good output and thermal protection. The start-up inrush current can be adjusted using an external capacitor. Auxiliary power override is supported for voltages higher than 9V applied to the AUX pin.

802.3at, 802.3af and up to 90W power levels are all supported by configuring external components.