The maximum frequency of operation for the SN74HCT244NSR is 40 MHz.
Yes, the SN74HCT244NSR is compatible with 5V systems, but it's recommended to use a voltage regulator to ensure a stable 5V supply.
The SN74HCT244NSR has a thermal pad on the bottom of the package. Ensure good thermal contact between the thermal pad and a heat sink or a metal plate on the PCB to dissipate heat effectively.
Use a 4-layer PCB with a solid ground plane and a separate power plane. Keep the signal traces short and away from the power planes to minimize noise and crosstalk.
The SN74HCT244NSR is rated for operation up to 125°C. However, it's recommended to derate the device's performance and consider thermal management for high-temperature applications.