SN74HC21DR datasheet by Texas Instruments

SN74HC21DR Frequently Asked Questions (FAQs)

• What is the maximum frequency of operation for the SN74HC21DR?
  The maximum frequency of operation for the SN74HC21DR is 25 MHz.
• Can I use the SN74HC21DR in a 5V system?
  Yes, the SN74HC21DR is compatible with 5V systems, but it's recommended to use a voltage regulator to ensure a stable 5V supply.
• How do I handle the output enable (OE) pin?
  The output enable (OE) pin is active-low, meaning it should be connected to GND to enable the outputs. Leaving it unconnected or connecting it to VCC will disable the outputs.
• What is the propagation delay of the SN74HC21DR?
  The propagation delay of the SN74HC21DR is typically around 10-15 ns, but this can vary depending on the operating conditions and load capacitance.
• Can I use the SN74HC21DR in a 3.3V system?
  Yes, the SN74HC21DR is compatible with 3.3V systems, but the output voltage will be limited to around 3.3V. Ensure that the load devices can operate with this reduced voltage.