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Binary Quaternary Encoder Decoder

IP.com Disclosure Number: IPCOM000090626D
Original Publication Date: 1969-Jun-01
Included in the Prior Art Database: 2005-Mar-05
Document File: 2 page(s) / 35K

Publishing Venue

IBM

Related People

Weiss, L: AUTHOR

Abstract

The circuit implementation of a compatible binary-to-quarternary converter and a quarternary-to-binary converter is realized as shown in drawings 1 and 2 respectively. The relative levels of both the binary and quarternary signals are shown in drawing 3. A truth table is shown in drawing 4.

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Binary Quaternary Encoder Decoder

The circuit implementation of a compatible binary-to-quarternary converter and a quarternary-to-binary converter is realized as shown in drawings 1 and 2 respectively. The relative levels of both the binary and quarternary signals are shown in drawing 3. A truth table is shown in drawing 4.

In drawing 1, although the emitter resistor of the A input current switch is designated R/2, 11 + 212 is required when transistors 2 and 4 conduct respectively. Reference voltage Vref is approximately in the middle of the signal swing excursions of the A and B inputs. Voltage Vc is somewhat higher than ground, while the up level of A and B is at ground. When A and B are both at the plus level +, no current flows through Rc1 and output T is at level a, drawings 3 and 4. When only A is positive, 12 flows through Rc1 and output T is at level b. For the case where only B is positive, 11 flows through Rc1 and output T is at level c, since 11 = 2I2. Where A and B are both negative, then 311 flows through the output resistor yielding the level d for output T.

In drawing 2, reference voltage Vref is in the center of the quarternary signal. Therefore, for the input T at either the a or b levels, output A is plus. For the c or d input levels, A is minus. Since the output A is used as the reference voltage for the current switch composed of transistors 3 and 4, when A is plus, output B is plus when input T is at a. B is minus when input T is at b. When A...