Tektronix 7834

Theory of Operation-7834
This portion of the Theory of Operation section provides a detailed description of the electrical
operation and relationship of
the circuits in the 7834 . The theory of operation for circuits unique
to this
instrument
is described in detail in this discussion .
Circuits commonly used in the electronics industry are
not described in detail . If more information is desired on these com-
monly used circuits, refer to the following textbooks :
Gordon V . Deboo, "Integrated Circuits and Semiconductor Devices", McGraw-Hill, New York, 1971 .
Jacob Milman and Herbert Taub, "Pulse, Digital and
Switching Waveforms", McGraw-Hill, New York, 1965 .
Albert Paul Malvino,
"Transistor Circuit Approximations", McGraw-Hill, New York, 1973 .
The following circuit analysis is accompanied by supporting illustrations
that give the names of the individual stages within
the major
circuits, and show how they are connected together to form the major circuit
. These illustrations also show the
inputs and
outputs
for
each circuit and the relationship of the front-panel controls to the individual stages . The detailed
circuit diagrams
from which the illustrations are derived are shown in the Diagrams section .
LOGIC
FUNDAMENTALS
Digital logic techniques are
used to perform many functions
within the instrument . The function and
operation of the
logic circuits are described using logic symbology and termi-
nology . This portion of the manual is provided to aid in the
understanding of these symbols and logic concepts,
not
a
comprehensive discussion of the subject . For further infor-
mation on binary number systems and the associated Bo-
olean algebra concepts, the derivation
of
logic
functions, or
a more detailed analysis of digital logic, refer
to
the follow-
ing textbooks :
Robert C . Baron and Albert T . Piccirilli, "Digital
Logic
and Computer Operation", McGraw-Hill, New York,
1967 .
Thomas C . Bartee, "Digital Computer Fundamentals",
McGraw-Hill, New York, 1966 .
Yaohan
Chu,
"Digital Computer Design Fundamentals",
McGraw-Hill, New
York, 1962 .
Joseph Millman and Herbert
Taub, "Pulse, Digital and
Switching Waveforms", McGraw-Hill, New York,
Chap-
ters 9-11, 1965 .
Symbols
The operation
of circuits in this instrument which use digital
techniques
is described using the graphic symbols set forth
in military
standard MIL-STD-806B . Table 3-1 provides a
basic logic reference
for the logic devices used within this
DETAILED
CIRCUIT OPERATION
instrument . Any deviations from the standard symbology,
or devices not defined by the standard are described in the
circuit description for the applicable device .
NOTE
Logic Symbols used on the diagrams depict the
logic function
as used in this instrument and
may differ from the manufacturer's data .
Logic Polarity
All
logic functions are described using the positive logic
convention . Positive logic is a system of notation where the
more positive of two levels (H I) is called the true or 1-state ;
the more negative level (LO) is called the false or 0-state .
The HI-LO
method of notation is used in this logic descrip-
tion . The specific
voltages that constitute a HI or LO state
vary between individual
devices . Whenever possible, the
input and output lines are named to indicate
the function
that they perform when at the H I (true) state .
Input/Output Tables
Input/Output (truth) tables are used to show the input
combinations important
to a particular function, along with
the resultant output
conditions . This table may be given
either for an individual
device or for a complete logic stage .
For examples of
input/output tables for individual devices,
see Table 3-1 .