The maximum frequency of operation for the CD74HC125E is 40 MHz.
Yes, the CD74HC125E is compatible with 5V systems, but it's recommended to use a voltage regulator to ensure a stable 5V supply.
The enable pins (EN1 and EN2) are active-low, meaning they need to be pulled low to enable the corresponding buffer. You can tie them to GND or use a logic signal to control them.
The propagation delay of the CD74HC125E is typically around 10-15 ns, but it can vary depending on the operating conditions and load capacitance.
Yes, the CD74HC125E is compatible with 3.3V systems, but you may need to adjust the input signal levels and ensure that the output voltage is within the recommended range.