STEVAL-TSP004V2

STEVAL-TSP004V2 Data brief 5 V/4 A, synchronous flyback converter, Power Over Ethernet (PoE) - IEEE 802.3at compliant reference design Features IEEE 802.3at compliant PD interface Works with power supplied from Ethernet LAN cables or from local auxiliary sources Line input voltage range: 40 to 60 V DC Output voltage: 5 V 5% DC Output current: 4 A Peak-to-peak output ripple: < 30 mV Efficiency DC-DC full-load: > 92% Overall peak efficiency: > 89% Transient response V to 50% load step: < 170 mV OUTPK-PK V in load line case: < 0.5% RoHs compliant Description The STEVAL-TSP004V2 is a reference design for a PoE+, high-efficiency, 5 V/4 A flyback converter based on the PM8803 PoE controller. The PM8803 is a highly integrated device embedding an IEEE802.3at-compliant powered device (PD) interface together with a PWM controller and support for auxiliary sources. The STEVAL-TSP004V2 reference design is based on an isolated flyback CCM Product summary converter featuring synchronous rectification with gate driver transformer. 5 V/4 A, synchronous fly- back converter, Power STEVAL- Over Ethernet (PoE) - IEEE TSP004V2 802.3at compliant reference design High efficiency integrated IEEE 802.3at PoE-PD interface and PWM controller type 2 PSE PM8803 indicator, plus support for forward active clamp topology DB2569 - Rev 2 - May 2019 www.st.com For further information contact your local STMicroelectronics sales office.STEVAL-TSP004V2 Detailed description 1 Detailed description The STEVAL-TSP004V2 reference design for the PM8803 covers a broad range of Power over Ethernet (PoE) applications. The PM8803 is a highly integrated device embedding an IEEE802.3at-compliant powered device (PD) interface together with a PWM controller and support for auxiliary sources. Although the PM8803 can be configured to work in several isolated topologies (self-driven or transformer gate- driven), we focus here on a high-efficiency isolated flyback converter topology with synchronous rectification, 5 V output voltage and 4 A output current capability. Auxiliary sources can be connected to the reference design on two different input connectors: one input (AUX II) allows prevalence of the auxiliary sources with respect to the PoE, whereas the other input (AUX I) allows the use of a wall adapter with voltage lower than the internal PoE UVLO threshold, while still benefitting from the inherent inrush and DC current limit. The possible configurations supported by the STEVAL-TSP004V2 reference design are: input diode bridges (four possible options, including active bridges) optional 4-pair detection circuit to detect a high power PSE source optional booster circuit to increase the max. input current over 800 mA diode or synchronous rectification (four package options for diode and three package options for MOSFET) primary side snubber (three options including active clamp) power transformer (three size options for transformer gate-driven solutions and two size options for self- driven applications) 1.1 Efficiency Figure 1. STEVAL-TSP004V2 reference design: 5 V overall and DC-DC efficiency OUT DB2569 - Rev 2 page 2/5