HI Team,
My customer is asking what's the meaning of below POC network requirement marked in red? Does it mean that the voltage ripple at 30/60Hz frequency of POC can't exceed the 500mVpp? Why we have this requirement particular for 30/60Hz? If customer is violating this spec, will it cause any communication or link lost issue?
Do we have the ripple for the whole frequency spectrum?
Hello,
The purpose of the specification is to define how much the voltage can drop due to sensor frame rate. The attached image shows the voltage at the input of the DC regulator. There is a constant Vpoc noise shown in the signal but there is also periodic voltage spikes which are caused by whether the sensor is capturing valid frame data or blanking. During the blanking period of the sensor current draw from the system is reduced and the voltage jumps up. The specification is in regards to the maximum amount the voltage should spike during a blanking period referred to as Vpoc Pulse below.
To answer your second question, if the voltage spikes more than the 500mVpp than it is quite possible that link issues will occur. These transients can be fed back through the PoC network and effect the SERDES link or the power rails required to run the SER/DES.
Regards,
Nick
