The maximum clock frequency of the LTC1418AIG#PBF is 50MHz, but it can be overclocked to 65MHz with some limitations on the analog-to-digital converter (ADC) performance.
To optimize the layout, keep the analog and digital grounds separate, use a solid ground plane, and keep the analog input traces short and away from digital traces. Also, use a low-ESR capacitor for the VCC pin and a 0.1uF capacitor for the AVCC pin.
The recommended power-up sequence is to power up the VCC pin first, followed by the AVCC pin, and then the digital inputs. This ensures that the analog circuitry is powered up before the digital circuitry.
Yes, the LTC1418AIG#PBF can be used in a multi-channel application by using multiple devices or by using a multiplexer to switch between multiple analog input channels.
The digital output data from the LTC1418AIG#PBF is in a 16-bit parallel format. You can use a microcontroller or an FPGA to read and process the data. Make sure to use a suitable interface, such as a 16-bit bus or a serial interface, to transfer the data.