Hi there：
we are using DLPC230S-Q1 for projector design. As we found in the datasheet of DLPC230S-Q1, there is an internal termination in it
but when we test the waveform, we found a wave reflection there.
Do we need any configuration to open the internal termination?
and we also found an option with the internal termination in DLPC230S-Q1's IBIS model
Hi Zhangyi,
The DLPC230 does have a default ~100-ohm resistor for the OpenLDI interface like you have mentioned.
You do not need to configure the resistor, as it is default.
May I ask what kind of reflection you are seeing when you are measuring by any chance? I would also like to take a step back and ask how you are measuring the signal. Is it with a ground lead or with a tip-and-barrel method (AKA paperclip) method? Maybe differential probes?
If a ground clip was used, it may be better to go with the other two methods listed above, as a ground clip makes a large inductance loop that causes ringing. There is a possibility the probe may have resistance as well. It is recommended you get a probe with minimal resistance for this case if you have not already done so.
Here is an example of a large ground loop formed by a ground clip:
and an example of the tip-and-barrel method that has a much smaller loop:
If you do not have one of these available, you can actually make your own by tightly wrapping wire around your probe tip after removing the witch's hat, as shown below:
Best regards,
Michael Ly
Hi, Micheal
we use the differential probe to test the waveform。
And we find that input of the DLPC230 from OpenLDI，it says it support spread spectrum,
Does it mean it can support PCLK with a spread spectrum? or it has a software option to open the spread spectrum option on DLPC230
