PD70224 IdealBridge™ Dual MOSFET-Bridge Rectifier

Microchip Technology's PD70224 is a dual pack of MOSFET-based full-bridge rectifiers. It contains low-RDS 0.16 Ω N-channel MOSFETs for much higher overall efficiency and higher output power, particularly when used in powered devices (PDs) for Power over Ethernet (PoE) applications. The entire drive circuitry for driving the MOSFETs is on-chip, including a charge pump for driving the high-side N-channel MOSFETs. The total forward drop (bridge offset) introduced by the IdealBridge rectifier is only 192 mV at 0.6 A, compared to a standard bridge rectifier that typically presents 2000 mV of forward drop. PD70224 IdealBridge can support over 1 A current, making it the ideal choice not only for modern energy-saving 2-pair applications compliant with IEEE 802.3af and IEEE 802.3at (Type 1 and Type 2) but also 4-pair PDs such as IEEE 802.3bt and Power over HDBase-T (PoH). In addition, PD70224 can help identify at the physical layer itself whether a 2-pair PSE or a 4-pair PSE is providing power over the cable. It does this by sensing the pair's voltage on the line (un-rectified) side.