The SN65LVDS9638DGK: With two drivers and no receivers (2/0 configuration), it is a pure transmit-side part for point-to-point or multidrop clock and data distribution over twisted-pair or PCB traces.
The 400 Mbps per-channel data rate is the headline spec for this driver. That translates to 400 Mbit/s NRZ on each of the two outputs.
Package and footprint realities
Housed in an 8-VSSOP (DGK suffix), the device occupies a 3.00 mm × 3.00 mm footprint — tight enough for space-constrained PCIe add-in cards or compact camera modules. The 0.65 mm pin pitch is standard for MSOP-8, so layout guides from the datasheet apply directly.
For dual-sourcing resilience, the 65LVDS9638 base number is a single-sourced TI part; no official second-source cross-reference appears in the record.