SN74HC139PWRE4

Logic - Signal Switches, Multiplexers, Decoders have been a common part of electronics for years. They have traditionally been used to control the flow of electrical signals, to convert from one type of signal to another, or to route data from one area to another. The SN74HC139PWRE4 is an example of such a device. This dual 2-to-4 line decoder/demultiplexer IC is capable of addressing up to four different digital inputs with two select inputs and enabling individual output channels. In this article, we will explore its application areas, as well as its working principle.

Application Fields of the SN74HC139PWRE4

The SN74HC139PWRE4 is a commonly used dual 2-to-4 line decoder/demultiplexer. It is primarily used to decode a two-bit input value (select inputs) into four output lines. It can be used for decoding, timing, and addressing in digital circuits. Some of its most common applications are listed below:

• It can be used to decode ROM data.
• It can be used in large multiplexers and demultiplexers.
• It can be used in timing circuits.
• It can be used in addressable LED drivers.
• It can be used as a logic OR gate.
• It can be used in 4-bit data buses.

Working Principle of the SN74HC139PWRE4

The SN74HC139PWRE4 is a CMOS integrated circuit (IC) which contains two independent 2-to-4 line decoders/demultiplexers internally. The device has two select inputs (S1, S2) and four outputs (Q0-Q3). When either S1 or S2 is at a low (logic 0) state, all the outputs will be held in the low (logic 0) state. When two select inputs (S1 and S2) are at a high (logic 1) state, the outputs (Q0-Q3) will be enabled according to the logic table. Whenever one of the inputs (S1 or S2) changes state, the outputs will change accordingly.

The SN74HC139PWRE4 raises the output of the appropriate output line when two select inputs (S1 and S2) are at the high (logic 1) state and the corresponding input lines are at the low (logic 0) state. For example, if both S1 and S2 are at the high (logic 1) state and I0 and I1 are at the low (logic 0) state, then the output of Q0 will be at the high (logic 1) state. Similarly, if S1 and S2 are both at the high (logic 1) state and I2 is at the low (logic 0) state, then the output of Q2 will be at the high (logic 1) state.

Conclusion

The SN74HC139PWRE4 is a Dual 2-to-4 line decoder/demultiplexer IC, which is capable of addressing up to four different digital inputs with two select inputs and enabling individual output channels. It can be used as a logic OR gate, in ROM data decoding, timing, addressable LED drivers and 4-bit data buses. The SN74HC139PWRE4 raises the output of the appropriate output line when two select inputs (S1 and S2) are at the high (logic 1) state and the corresponding input lines are at the low (logic 0) state. This can be much more efficient than using multiple IC’s for each output.