Philips PM2521 Service Manual page 114

Hef4051B
8-CHANNEL
ANALOGUE
MULTIPLEXER/DEMULTIPLEXER
Functional diagram
[iil [Til [Tsl
[121
rnl
ra
m
''dD
'^2
Yl
Yq Y3
0
< A2
D
HEF
4051 B
Y4 Vg
Z Y7 Y5 E
Vee
YSS
llJ
I
2
J
UJ
[AJ LlJ LLl 12J L§J
Pinning diagram
PINNING
Yq
1^0
independent inputs/outputs
Aq
to
A2
address inputs
E enable input
(active
LOW)
Z
common
input/output
FUNCTION TABLE
inputs
channel
ON
E
Az
1
0
<
L L L
L
L L L
H
L
L
H
L
y '-2
L
L
H H
L
H
L L
L
H
L
H
L
H H
L
L
H H
H
H
X
X
X
none
H =
HIGH
state (the
more
positive voltage)
L =
LOW
state (the
less
positive voltage)
X
=
state
in
immaterial