SN65DPHY440SS: placed close to AP or LCD screen?

SN65DPHY440SS can be used in either a MIPI CSI-2 or MIPI DSI application at datarates of up to 1.5 Gbps. Which interface and data rate does LCD screen support?

The placement of SN65DPHY440 and the cable length depends on the max supported data rate and insertion loss of the cable. SN65DPHY440 has a 5dB RX equalizer and 2.5dB TX pre-emphasis. Please refer to section 8 of SN65DPHY440 for more detail on the design.

Thanks

David

Both TX Pre-emphasis and RX equalization work together to compensate for the high-frequency channel loss. But the approach to the compensation is different. Pre-emphasis inverts, shifts, and shrinks the adjacent symbols to boost the bit transition. Linear equalizer amplifies the gain in certain frequency ranges.

While both pre-emphasis and equalization compensate for the high-frequency channel loss, both have their advantage and disadvantage. 

Since equalization amplifies the gain in a certain frequency range, if the noise introduced in the channel is in the optimal frequency range of the equalization, the noise component gets boosted and negatively impacts the correct sampling of the data stream and clock data recovery.

Pre-emphasis enhances the signal by increasing the signal edge rate, and this in turn will cause increased cross-talk on the neighboring channel. 

So the selection between RX equalization and TX pre-emphasis is system dependent. Each system needs to be evaluated to maximize the advantage of pre-emphasis and equalization. Typically this evaluation is done through channel response simulation.

Thanks

David