SLVSF02D March 2019 – May 2020 TPS23881
The TPS23881 is an 8-channel, IEEE 802.3bt ready PoE PSE controller and can be used in high port count semiauto or fully micro-controller managed applications (The MSP430FR5969 micro-controller is recommended for most applications). Subsequent sections describe detailed design procedures for applications with different requirements including host control.
The schematic of Figure 122 depicts semiauto mode operation of the TPS23881, providing functionality to power PoE loads. The TPS23881 can do the following:
Following a power-off command, disconnect or shutdown due to a Start, PCUT or ILIM fault, the port powers down. Following port power off due to a disconnect, the TPS23881 will immediate restart the detection and classification cycles if the DETE and CLE bits are set in register 0x14. If the shutdown is due to a start, PCUT or ILIM fault, the TPS23881 enters into a cool-down period during which any Detect/Class Enable Command for that port will be delayed. At the end of cool down cycle, one or more detection/class cycles are automatically restarted if the class and/or detect enable bits are set. If a port is disabled using the power off command, the DETE and CLE bits will be cleared and these bits will need to be reset over I2C in order for detection and classification to resume.