BUY SN74HCT138N https://www.utsource.net/itm/p/496939.html
The ’HCT138 devices are designed for high-performance memory-decoding or data-routing applications requiring very short propagation delay times. In high-performance memory systems, these decoders can minimize the effects of system decoding. When employed with high-speed memories utilizing a fast enable circuit, the delay times of these decoders and the enable time of the memory usually are less than the typical access time of the memory. This means that the effective system delay introduced by the decoders is negligible. The conditions at the binary-select inputs and the three enable inputs select one of eight output lines. Two active-low (G) and one active-high (G) enable inputs reduce the need for external gates or inverters when expanding. A 24-line decoder can be implemented without external inverters, and a 32-line decoder requires only one inverter. An enable input can be used as a data input for demultiplexing applications.

Parameter	Symbol	Conditions	Min	Typ	Max	Unit
Supply Voltage	VCC	-	2.0	4.5	5.5	V
Input Low Voltage	VIL	-	0.0	0.8	-	V
Input High Voltage	VIH	-	-	2.0	VCC	V
Output Low Voltage	VOL	IOL = 4 mA	0.0	0.4	-	V
Output High Voltage	VOH	IOH = -0.4 mA	-	2.4	VCC	V
Input Leakage Current	IIL	VCC = 5 V	-1.0	-	-	μA
Output Leakage Current	IOL	VCC = 5 V, VO = 5 V	-0.1	-	-	μA
Propagation Delay Time	tpd	VCC = 5 V, TA = 25°C	-	18	-	ns
Power Dissipation	PD	-	-	-	500	mW

Instructions for Use:

1. Supply Voltage (V_CC):

   • The SN74HCT138N operates within a supply voltage range of 2.0 V to 5.5 V. Ensure that the supply voltage is stable and within this range to avoid damage to the device.

2. Input Voltages:

   • Input low voltage (V_IL) should be between 0.0 V and 0.8 V.
   • Input high voltage (V_IH) should be between 2.0 V and V_CC.

3. Output Voltages:

   • When the output is low (V_OL), it should be less than or equal to 0.4 V when sourcing 4 mA.
   • When the output is high (V_OH), it should be at least 2.4 V when sinking -0.4 mA.

4. Leakage Currents:

   • Input leakage current (I_IL) should not exceed -1.0 μA at 5 V supply voltage.
   • Output leakage current (I_OL) should not exceed -0.1 μA at 5 V supply voltage and 5 V output voltage.

5. Propagation Delay Time (t_pd):

   • The propagation delay time is typically 18 ns at 5 V supply voltage and 25°C ambient temperature. This is the time it takes for a change in input to affect the output.

6. Power Dissipation (P_D):

   • The maximum power dissipation for the device is 500 mW. Ensure that the device is not operated beyond this limit to prevent overheating and potential damage.

7. Handling:

   • The SN74HCT138N is sensitive to electrostatic discharge (ESD). Handle the device with appropriate ESD protection measures to avoid damage.

8. Mounting:

   • Ensure proper mounting and soldering techniques to avoid mechanical stress on the device. Follow the recommended footprint and soldering profiles provided by the manufacturer.

9. Testing:

   • Before integrating the device into a circuit, test it under controlled conditions to ensure it meets the specified parameters.

10. Storage:

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

For more detailed information, refer to the datasheet provided by the manufacturer.

(For reference only)