74LVC139PW,112

Logic-signal switches, multiplexers, decoders are essential components for digital systems, and a relevant example is the 74LVC139PW,112. This section explains the application fields and working principle of this device.

Application Fields of 74LVC139PW,112

The 74LVC139PW,112 is a 2-line to 4-line decoder/demultiplexer, which is commonly used in logic-signal switching, multiplexing, and decoding applications. It is operated at voltage level up to 5.5 V, however, the device still retains the same fundamental characteristics of the 74LVC139 family, which includes operation at 3.3V and 2.5V. The operating temperature range of the device is -40°C to +125°C.

This device consists of two independent 2-to-4 line decoders that accept two binary coded inputs (A0, A1) and provide four active low outputs (Y0 to Y3). The outputs are fully demultiplexed and exhibit multiplexed address inputs. When enabled by the Enable (G) input, the decoded outputs are active and remain active until a new address is present or the enable signal is inactive. Outputs are disabled and remain in their last state for power-up reset, or when new address inputs present.

The 74LVC139PW,112 is also used for data transmission and bus-based computing applications, as it is particularly designed for low voltage applications, such as 5V CMOS, LVCMOS, LVTTL, ALVC, etc. As an example, the decoder can be used with an asynchronous 8-bit micro-controller, to divide the system data into 16 bytes.

Working Principle of the 74LVC139PW,112

The 74LVC139PW,112 works by taking two binary coded inputs (A0 and A1) and converting them into four active low outputs (Y0 to Y3). When enabled (G) is low and both A0 and A1 inputs are low (0000), Y0 is low and all other outputs are high respectively. As A0 and A1 are increased, the respective output is low. Y1 will be low for a 01 input, Y2 for a 10 and Y3 for a 11. Every possible combination of A0 and A1 will produce a single output (Y) that is equal to the logic high (+vcc). Additionally, the Enable (G) input allows for the parallel decoding of inputs A0 and A1.

The 74LVC139PW,112 is an active low device, meaning that the inputs and outputs must be logical low (0 V), and logical high (5 V). This device is activated when the Enable Pin (G) is low, and its values on the A0 and A1 pins are 0, 1, 2, 3 respectively. When the Enable Pin is high, all outputs are high regardless of the values on the A0 and A1 pins.

Conclusion

The 74LVC139PW,112 is a type of logic-signal switch, multiplexer, and decoder that can be used in data transmission and bus-based computing applications. It works by taking two binary coded inputs (A0 and A1) and converting them into four active low outputs (Y0 to Y3). Additionally, the Enable (G) input allows for the parallel decoding of inputs A0 and A1.