M74HC138B1R datasheet by STMicroelectronics

M74HC138B1R Frequently Asked Questions (FAQs)

• What is the maximum frequency of operation for the M74HC138B1R?
  The maximum frequency of operation for the M74HC138B1R is typically 25 MHz, but it can vary depending on the specific application and operating conditions.
• How do I ensure that the M74HC138B1R is properly powered?
  The M74HC138B1R requires a single power supply voltage (VCC) of 2.0 to 6.0 volts. Ensure that the power supply is stable and decoupled with capacitors to minimize noise and voltage drops.
• What is the purpose of the enable inputs (E1, E2, and E3) on the M74HC138B1R?
  The enable inputs (E1, E2, and E3) are used to enable or disable the decoder/demultiplexer function. When any of these inputs are low, the outputs are disabled and in a high-impedance state.
• How do I select the correct output line using the address inputs (A0, A1, and A2) on the M74HC138B1R?
  The address inputs (A0, A1, and A2) are used to select one of the eight output lines (Y0 to Y7). The output line is selected based on the binary code applied to the address inputs, with A2 being the most significant bit and A0 being the least significant bit.
• What is the output current capability of the M74HC138B1R?
  The output current capability of the M74HC138B1R is typically 20 mA per output line, but it can vary depending on the specific application and operating conditions.