The maximum frequency of operation for the SN74LS245DBR is 30 MHz.
No, the SN74LS245DBR 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.
When not in use, the enable inputs (G1 and G2) should be tied to VCC or GND to prevent floating inputs. This ensures that the device operates correctly and minimizes power consumption.
The SN74LS245DBR can sink up to 24 mA and source up to -15 mA per output pin.
The SN74LS245DBR is rated for operation up to 70°C. If your application requires operation at higher temperatures, you may need to consider a different device or take additional thermal management measures.