SN74ALS139NE4 Overview
It is embedded in a PDIP-16 package so that it can be taken anywhere.Packing the encoder in a Tube case would be a good idea.A supply voltage of 5 V is used in the operation of this converter.The SN74ALS139 series includes this electrical quadrature encode.I have noticed that the encoder definition has Dual on it.
SN74ALS139NE4 Features
In PDIP-16 package
Dual circuits

SN74ALS139NE4 Applications
There are a lot of Texas Instruments
SN74ALS139NE4 Encoders, Decoders, Converters applications.

Lighting Control
Low-voltage operation
Extended temperature range
Low power consumption
UART Interfacing
Infrared Data Communications
Audio
Automotive
Broadband
Digital Control

Package / Case	PDIP-16
Mounting Style	Through Hole
RoHS	Details
Logic Family	ALS
Minimum Operating Temperature	0 C
Maximum Operating Temperature	+ 70 C
Packaging	Tube
Series	SN74ALS139
Function	Decoder/Demultiplexer
Operating Supply Voltage	5 V
Number of Circuits	Dual
Logic Type	Decoders/Demultiplexers
Operating Temperature Range	0 C to + 70 C
High Level Output Current	- 0.4 mA
Low Level Output Current	8 mA
Number of Input Lines	2 Input
Number of Output Lines	4 Output
Product	Decoders / Demultiplexers
Height	4.57 mm
Length	19.3 mm
Width	6.35 mm