74HCT138

BUY 74HCT138 https://www.utsource.net/itm/p/1286127.html
3-to-8 line decoder/demultiplexer; inverting3-8/ ；

Instructions for Using 74HCT138:

1. Supply Voltage:

   • The 74HCT138 operates within a supply voltage range of 2.0V to 6.0V. Ensure that the supply voltage is stable and within this range to avoid damage or incorrect operation.

2. Input Voltage Levels:

   • For reliable operation, input low voltages should be between 0.8V and 1.5V, and input high voltages should be between 2.0V and 3.5V when V_CC is between 4.5V and 5.5V.

3. Output Voltage Levels:

   • When the output is low, the voltage should not exceed 0.4V under a load current of 4mA.
   • When the output is high, the voltage should be at least 2.4V under a load current of -0.4mA.

4. Leakage Current:

   • Input and output leakage currents should be kept below 20μA to ensure proper functioning of the device.

5. Propagation Delay:

   • The typical propagation delay time is 18ns, with a maximum of 35ns. This is important for timing considerations in your circuit design.

6. Power Dissipation:

   • The maximum power dissipation per package is 100mW. Ensure adequate heat dissipation if the device is operating near this limit.

7. Pin Configuration:

   • Refer to the datasheet for the specific pin configuration of the 74HCT138. Common pins include:
     • V_CC: Power supply
     • GND: Ground
     • E1, E2, E3: Enable inputs
     • A, B, C: Address inputs
     • Y0 to Y7: Output lines

8. Enable Inputs:

   • The enable inputs (E1, E2, E3) control whether the outputs are active. All three must be low for the outputs to be active.

9. Address Inputs:

   • The address inputs (A, B, C) select which output line will be active. The active output corresponds to the binary value of A, B, and C.

10. Output Lines:

    • The 74HCT138 has eight output lines (Y0 to Y7). Only one output is active at a time, based on the address inputs and enable conditions.

11. Handling:

    • Handle the 74HCT138 with care to avoid static damage. Use appropriate ESD protection measures during handling and installation.

12. Storage:

    • Store the device in a dry, cool place to prevent moisture damage and ensure long-term reliability.

For more detailed information, refer to the official datasheet of the 74HCT138.