Hello,
Our customer is seeing a problem on our product which uses a TFP410 encoder in which the DVI Tx diff out clock frequency is jumping from 121.5MHz (1400x1050@60Hz) to ~153MHz for about 9us interval. The IDCLK input is reported to be stable during this event as well as the DC power supply. Based on the frequency jump failure results where it changes from 121MHz to 153Mhz in one clock period (see CH1 scope shot below), were surmising that the TFP410 has an internal DLL and what our customer is seeing is a skip on a DLL tap selection.
My question is does the TFP410 use an internal DLL? If so, what else besides input (ref) clock and power quality what else could cause the observed failure our customer is seeing? If there is no internal DLL are there any other means that would cause the frequency to jump momentarily?
Thx