Hi team,
My customer is studying TI PSE solution.
TI separate two tones for single signature and dual signature detection.
May I know what the way to decide which type to start running from PSE? Thanks.
Hi Feng Bin,
For TPS23880 4-pair configured ports, the device performs a four point detection followed by a connection check. During the connection check both channels are probed to determine if the load is single signature or dual signature. Following the connection check the device will perform either a secondary four point detection or parallel four point detection based off the connection check.
If this post answers your question, please kindly mark this thread as resolved.
Very Respectfully,
Brandon Beader
Hi Brandon,
Thank for your explanation.
The waveform that you show it seems that PSE will feed the different patent of connection check for dual signature and single signature.
How does our PSE know to feed the difference patent between of dual signature and single signature since we didn't know the PD signature status before connection check. The waveform looks like the connection check result. But, customer would like to know what kind of signal PSE feed and how does PD respond during connection check will induce this waveform. Thanks.
Hi Feng bin,
I think there is some confusion based on the waveforms in the data sheet. The connection check probes both channels to determine if it is Single Signature or Dual Signature. If device is single signature, during connection check when both channels are probed there will be interference and produce invalid detection. For dual signature if both channels are probed simultanesouly there will be valid detection on both channels. The waveform in the data sheet shows a successful single signature connection check on the top vs a successful dual signature on the bottom. I have also included a discovery and sequence slide for added understanding.
Very Respectfully,
Brandon Beader
