Analog Devices / Maxim Integrated EVAL-LTC9105-AZ Evaluation Board

The LTC9105 provides IEEE 802.3af-, IEEE 802.3at-, and IEEE 802.3bt-compliant interfacing with port voltage and current telemetry via I²C. It utilizes an external, low channel resistance, R_DS(ON) (34mΩ typical), N-channel, hot-swap metal-oxide semiconductor, field-effect transistor (MOSFET), and 50mΩ sense resistor. Automatic maintenance of the power signature (MPS) keeps the port connected when the current drops to a low level.

The MAX5974C controls a DC/DC converter utilizing a highly efficient active-clamp forward converter topology with synchronous rectification and provides an isolated 5V/9.2A output. The LT4321 controls eight low R_DS(ON) (57mΩ typical), N-channel MOSFETs to improve end-to-end power delivery efficiency further and ease thermal design. The ADuM1252 isolates I²C data between the LTC9105 and a host controller on a non-isolated ground domain.

The Analog Devices EVAL-LTC9105-AZ is configured as a Class 6 PD and accepts up to 51W of delivered power from a power sourcing equipment (PSE) via the RJ45 connector (J1). The EVAL-LTC9105-AZ can be powered by a local 55V_DC power supply using the auxiliary supply input terminals. With the DC590B I²C interface board connected to the EVAL-LTC9105-AZ, the EVAL-LTC9105-AZ graphical user interface (GUI) displays port telemetry and configuration options.