POWER OVER DATA LINES DETECTION AND CLASSIFICATION SCHEME

摘要

A PoDL system includes a PSE connected to a PD through wire pairs. In this case, differential data and DC power are transmitted by the same wire pair. Generally, a low voltage/current detection and classification routine is required whenever the power of a system is applied, to allow the PD to transmit its own PoDL requirement to a PSE. Described are various techniques for simplifying or removing an operation routine or increasing flexibility for the PoDL system. The techniques include indicating a specific PD operation voltage; disabling the UVLO circuit of the PD during the routine; using a voltage of an opposite polarity to two routines; using a voltage limiter or a surge protector to transmit PoDL information; detecting a loop resistance; using a PSE memory to store the previous result of the routine; and applying power to a PD communication circuit by using the wire pairs while an alternative power source applies power to a PD load. So, the PoDL system can be applied to various applications.