- IEEE 802.3af/at-Compliant PD Interface Circuit
- -39V to -57V Startup Input Voltage Range
- Active FET Bridge
- Demonstrates 2x2P PD and Multi-PD Redundancy Configurations
- Demonstrates an Isolated 100W Active-Clamped, Synchronous-Rectified Forward DC-DC Converter
- Isolated +12V Output at 8.4A
- PD Detection and Configurable Classification Signatures
- Internal UVLO at +38.6V
- Evaluates End Span and Midspan Ethernet Systems
- Proven PCB Layout
- Fully Assembled and Tested
- 高功率2x2P PD
- IEEE 802.3af/at用电设备(PD)
The MAX5992A/B evaluation kit (EV kit) is a fully assembled and tested surface-mount circuit board featuring the MAX5992A/B IEEE® 802.3af/at-compliant network powered device (PD) interface controller IC, which pro vides PD detection signature, PD classification signature, inrush current control, undervoltage lockout (UVLO), and active FET-bridge driver. The EV kit is a compact and low-cost design used in power-over-Ethernet (PoE) applications requiring DC power from an Ethernet network port for PDs, such as fiber-to-the-femotocell/ picocell/microcell, fiber-to-the-home/fiber-to-the-building (FTTH/FTTB), IP phones, wireless access nodes, and security cameras.
The EV kit features a 2x2P PD or multi-PD redundancy configuration using the ICs. The 2x2P powers a galvanically isolated 100W, 250kHz switching-frequency, activeclamped, synchronous-rectified forward DC-DC converter using the MAX5974D. The device circuit achieves high efficiency by using a forward DC-DC converter topology. The surface-mount transformer provides up to +1500V galvanic isolation for the output. The EV kit output voltage is configured for +12V and provides up to 8.4A load current.
Note: In the multi-PD redundancy mode, the total output power must be reduced to 50W, which is limited by the LAN transformer on board. Its port current must be limited to 1.2A per 2 pair.
The EV kit circuit receives its power from IEEE 802.3af/ at-compliant power-sourcing equipment (PSE). The PSE provides the required -44V to -57V DC power over a twisted-pair Ethernet network cable to the EV kit’s RJ45 connectors. The EV kit features an active FET bridge for separating the DC power provided by an end-span or mid-span Ethernet system