SITRONICS 25F83, Service Manual

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SERVICE MANUAL
1.2 Triple 2-Channel Analog Multiplexer/Demultiplexer HEF4053
(1) Description
The HEF4053 is a triple 2-channel analog
multiplexer/demultiplexer with a common
enable input (
E
). Each
multiplexer/demultiplexer has two
independent inputs/outputs (Y
0
and Y
1
), a
common input/output (Z), and select inputs
(Sn). Each also contains two-bidirectional
analogue switches, each with one side
connected to an independent input/output
(Y
0
and Y
1
) and the other side connected to
a common input/output (Z).
With (
E
cted (lo
) LOW, one of the two switches is
sele w impedance ON-state) by Sn.
With
E
HIGH, all switches are in the high
impedance OFF-state, independent of S
A
to
S
C
.
V
DD
and V
SS
are the supply voltage
connections for the digital control inputs (S
A
to
S
C
and
E
).
The V
DD
to V
SS
range is 3 to 15V. The analog
inputs/outputs (Y
0
, Y
1
and Z) can swing
between V
DD
as a positive limit and V
EE
as a
negative limit. V
DD
-V
EE
may not exceed 15 V.
For operation as a digital
multiplexer/demultiplexer, V
EE
is connected to
V
SS
(typically ground).
(2) Block Diagrams
Fig. 10
24