SN54HC21J datasheet by Texas Instruments

SN54HC21J Frequently Asked Questions (FAQs)

• What is the maximum operating frequency of the SN54HC21J?
  The maximum operating frequency of the SN54HC21J is 25 MHz, but it can vary depending on the specific application and operating conditions.
• How do I handle the output enable (OE) pin in my design?
  The output enable (OE) pin should be connected to a logic low (GND) to enable the outputs, and to a logic high (VCC) to disable the outputs. Leaving the OE pin floating can cause unpredictable behavior.
• What is the recommended power-on reset (POR) circuit for the SN54HC21J?
  A simple POR circuit can be implemented using a resistor, capacitor, and diode connected to the VCC pin. The capacitor should be discharged slowly to ensure a clean power-on reset.
• How do I ensure signal integrity and minimize noise in my design?
  Use proper PCB layout techniques, such as separating analog and digital signals, using ground planes, and adding decoupling capacitors to minimize noise and ensure signal integrity.
• Can I use the SN54HC21J in a 3.3V system?
  Yes, the SN54HC21J can operate in a 3.3V system, but the input voltage thresholds may vary. Ensure that the input signals meet the recommended voltage levels and that the output voltage levels are compatible with the receiving device.