December 1990 2
Philips Semiconductors Product specification
8-channel analog
multiplexer/demultiplexer with latch
74HC/HCT4351
FEATURES
• Wide analog input voltage range:
± 5 V
• Low “ON” resistance:
80 Ω (typ.) at V
CC
− V
EE
= 4.5 V
70 Ω (typ.) at V
CC
− V
EE
= 6.0 V
60 Ω (typ.) at V
CC
− V
EE
= 9.0 V
• Logic level translation: to enable 5 V logic to
communicate with ± 5 V analog signals
• Typical “break before make” built in
• Address latches provided
• Output capability: non-standard
• I
CC
category: MSI
GENERAL DESCRIPTION
The 74HC/HCT4351 are high-speed Si-gate CMOS
devices. They are specified in compliance with JEDEC
standard no. 7A.
The 74HC/HCT4351 are 8-channel analog
multiplexers/demultiplexers with three select inputs (S
0
to
S
2
), two enable inputs (E
1
and E
2
), a latch enable input
(LE), eight independent inputs/outputs (Y
0
to Y
7
) and a
common input/output (Z).
With E
1
LOW and E
2
is HIGH, one of the eight switches is
selected (low impedance ON-state) by S
0
to S
2
. The data
at the select inputs may be latched by using the active
LOW latch enable input (LE). When LE is HIGH the latch
is transparent. When either of the two enable inputs,
E
1
(active LOW) and E
2
(active HIGH), is inactive, all 8
analog switches are turned off.
V
CC
and GND are the supply voltage pins for the digital
control inputs (S
0
to S
2
, LE, E
1
and E
2
). The V
CC
to GND
ranges are 2.0 to 10.0 V for HC and 4.5 to 5.5 V for HCT.
The analog inputs/outputs (Y
0
to Y
7
, and Z) can swing
between V
CC
as a positive limit and V
EE
as a negative
limit.
V
CC
− V
EE
may not exceed 10.0 V.
For operation as a digital multiplexer/demultiplexer, V
EE
is
connected to GND (typically ground).
QUICK REFERENCE DATA
V
EE
= GND = 0 V; T
amb
=25°C; t
r
=t
f
= 6 ns
SYMBOL PARAMETER CONDITIONS
TYPICAL
UNIT
HC HCT
t
PZH
/ t
PZL
turn “ON” time E
1
, E
2
or S
n
to V
os
C
L
= 15 pF; R
L
=1 kΩ; V
CC
=5 V2735ns
t
PHZ
/ t
PLZ
turn “OFF” time E
1
, E
2
or S
n
to V
os
21 23 ns
C
I
input capacitance 3.5 3.5 pF
C
PD
power dissipation capacitance per switch notes 1 and 2 25 25 pF
C
S
max. switch capacitance
independent (Y) 5 5 pF
common (Z) 25 25 pF
Notes
1. C
PD
is used to determine the dynamic power
dissipation (P
D
in µW):
P
D
=C
PD
× V
CC
2
× f
i
+∑ {(C
L
+ C
S
)
× V
CC
2
× f
o
}
where:
f
i
= input frequency in MHz
f
o
= output frequency in MHz
C
L
= output load capacitance in pF
C
S
= max. switch capacitance in pF
∑ {(C
L
+ C
S
)
× V
CC
2
× f
o
} = sum of outputs
V
CC
= supply voltage in V
2. For HC the condition is V
I
= GND to V
CC
For HCT the condition is V
I
= GND to V
CC
− 1.5 V
ORDERING INFORMATION
See
“74HC/HCT/HCU/HCMOS Logic Package
Information”
.
