SN74HC138DRE4 datasheet by Texas Instruments

SN74HC138DRE4 Frequently Asked Questions (FAQs)

• What is the maximum frequency of operation for the SN74HC138DRE4?
  The maximum frequency of operation for the SN74HC138DRE4 is 25 MHz, but it can vary depending on the specific application and operating conditions.
• How do I ensure that the SN74HC138DRE4 is properly powered and decoupled?
  To ensure proper power and decoupling, use a 5V power supply, add a 0.1uF ceramic capacitor between VCC and GND, and consider adding additional decoupling capacitors near the device.
• What is the maximum current that the SN74HC138DRE4 can sink or source?
  The SN74HC138DRE4 can sink up to 6mA and source up to 5.2mA per output pin, but it's recommended to limit the current to 4mA per pin to ensure reliable operation.
• How do I handle the enable inputs (E1, E2, and E3) to ensure proper operation?
  The enable inputs (E1, E2, and E3) must be driven high or low; avoid floating or high-impedance states. Use a pull-up or pull-down resistor if the input is not driven by a logic signal.
• What is the propagation delay of the SN74HC138DRE4?
  The propagation delay of the SN74HC138DRE4 is typically around 10-15ns, but it can vary depending on the specific application and operating conditions.