CD74HC138E datasheet by Texas Instruments

CD74HC138E Frequently Asked Questions (FAQs)

• What is the maximum frequency of operation for the CD74HC138E?
  The maximum frequency of operation for the CD74HC138E is typically 25 MHz, but it can vary depending on the specific application and operating conditions.
• How do I ensure that the CD74HC138E is properly powered?
  To ensure proper power supply, connect VCC to a stable 2-6V power source, and GND to a reliable ground connection. Also, decouple the power supply with a 0.1uF capacitor to reduce noise.
• What is the maximum current that the CD74HC138E can sink or source?
  The CD74HC138E can sink or source up to 25mA of current per output pin, but it's recommended to limit the current to 10mA or less to ensure reliable operation.
• How do I handle the enable inputs (E1, E2, E3) to ensure proper operation?
  The enable inputs (E1, E2, E3) must be connected to a valid logic level (VCC or GND) to enable or disable the decoder. Floating or unconnected enable inputs can cause unpredictable behavior.
• What is the propagation delay of the CD74HC138E?
  The propagation delay of the CD74HC138E is typically around 10-15ns, but it can vary depending on the specific application and operating conditions.