Logic - Signal Switches, Multiplexers, Decoders

A CD74HC139MT is a high-speed CMOS series decoding multiplexer integrated circuit (IC) with two 4-to-16 line decoders sharing a common active-low enable. It is a extremely versatile IC with a wide range of application and uses. In this article we discuss its application field and working principle.

Application Field

CD74HC139MT has various application fields, including circuits for devices such as robotics, smart home, telephone and television systems and remote position systems. It has also implemented in a number of audio/visual equipment and other entertainment systems. It is a highly power- efficient device and can be used in battery operated systems, as well as in other portable applications where low-power dissipation is essential.

The CD74HC139MT is most commonly used to transmit and receive digital signals, actuating motors, and as an encoder or decoder in communication systems. Its wide range of features enables it to support audio, video, and other communication protocols. In addition, this device can also be used in applications such as controlling sensors, relaying information, and providing binary and/or diagnostic functions.

Working Principle

The CD74HC139MT works primarily on the principle of binary decoding. It is designed to receive two 4-bit binary signals, A and B, and decode them into a single 16-bit output signal. The output signal can be used to control relays, motors, indicators, and actuate digital devices such as counters. The sixteen outputs of the device are active-low, so each output can be enabled or inhibited by setting the appropriate level at the enable pin.

The circuit diagram of CD74HC139MT can be found in the user manual, which shows the pin connection of the device and the logic used for the binary decoder. To use the CD74HC139MT, the following inputs must be connected: A and B for the binary input signals, EN for the enable signal, VDD for the power supply, and VSS for ground.

The CD74HC139MT works in three states: enable, disable, and idle. In enable state, the binary input signals A and B are continuously monitored and any change in the binary inputs will cause the outputs to change accordingly. In disable state, the outputs remain at the same logic level, regardless of the inputs. In idle state, the outputs are turned off and the device is isolated from the rest of the connected circuit.

CD74HC139MT is a low-power CMOS device and its power consumption is only a few milliamps. The power consumption is much lower than other devices such as TTL, making it suitable for battery operated devices. The device can operate up to a voltage of 5.5V and over a temperature range from - 40 to + 85 degrees Celsius.

Conclusion

CD74HC139MT is an incredibly versatile and powerful logic device. It can be used for a variety of applications, from operating remote control systems to powering audio/visual equipment and more. The device is extremely power efficient and operates at a low voltage, making it suitable for battery-operated devices as well. Due to its wide range of features and functions, the CD74HC139 MT is a must-have for any type of electronics project.