The maximum operating frequency of the SN74LS240DW is 35 MHz.
No, the SN74LS240DW is a 5V device and is not compatible with 3.3V systems. You may need to use a level translator or a different device that is compatible with 3.3V systems.
The SN74LS240DW has a maximum power dissipation of 500 mW. To handle heat dissipation, ensure good airflow around the device, use a heat sink if necessary, and follow proper PCB design and layout guidelines.
Yes, the SN74LS240DW is compatible with TTL (Transistor-Transistor Logic) logic levels.
No, the SN74LS240DW is a commercial-grade device and is not suitable for high-reliability or aerospace applications. You may need to use a radiation-hardened or high-reliability device specifically designed for such applications.