74HC251; 74HCT251
8-input multiplexer; 3-state
Rev. 4 — 1 February 2016
Product data sheet
1. General description
The 74HC251; 74HCT251 is an 8-bit multiplexer with eight binary inputs (I0 to I7), three
select inputs (S0 to S2) and an output enable input (OE). The select inputs select one of
the eight binary inputs and route it to the complementary outputs (Y and Y). A HIGH on
OE causes the outputs to assume a high-impedance OFF-state. Inputs include clamp
diodes that enable the use of current limiting resistors to interface inputs to voltages in
excess of VCC.
2. Features and benefits
Input levels:
For 74HC251: CMOS level
For 74HCT251: TTL level
Low-power dissipation
Non-inverting data path
Specified in compliance with JEDEC standard no. 7A
ESD protection:
HBM JESD22-A114F exceeds 2 000 V
MM JESD22-A115-A exceeds 200 V
Multiple package options
Specified from 40 C to +85 C and from 40 C to +125 C
3. Ordering information
Table 1.
Ordering information
Type number
74HC251D
Package
Temperature range Name
Description
Version
40 C to +125 C
SO16
plastic small outline package; 16 leads; body width 3.9 mm SOT109-1
40 C to +125 C
SSOP16
plastic shrink small outline package; 16 leads;
body width 5.3 mm
40 C to +125 C
TSSOP16 plastic thin shrink small outline package; 16 leads;
body width 4.4 mm
74HCT251D
74HC251DB
74HCT251DB
74HC251PW
74HCT251PW
SOT338-1
SOT403-1
74HC251; 74HCT251
NXP Semiconductors
8-input multiplexer; 3-state
4. Functional diagram
,
Fig 1.
,
,
,
,
,
,
,
,
<
,
,
,
,
,
08/7,3/(;(5
6
<
,
6
,
6
2(
2(
6
6
6
<
DDD
Logic symbol
<
Fig 2.
DDD
Functional diagram
,
,
,
,
<
,
,
<
,
,
6
Fig 3.
6
6
2(
DDD
Logic diagram
74HC_HCT251
Product data sheet
All information provided in this document is subject to legal disclaimers.
Rev. 4 — 1 February 2016
© NXP Semiconductors N.V. 2016. All rights reserved.
2 of 18
74HC251; 74HCT251
NXP Semiconductors
8-input multiplexer; 3-state
5. Pinning information
5.1 Pinning
+&
+&7
,
9&&
,
,
,
,
,
,
<
,
<
6
2(
+&
+&7
,
6
*1'
,
,
,
,
,
<
,
<
6
6
2(
6
9&&
,
*1'
Fig 4.
6
DDD
DDD
Pin configuration SO16
Fig 5.
Pin configuration SSOP16 and TSSOP16
5.2 Pin description
Table 2.
Pin description
Symbol
Pin
Description
I0 to I7
4, 3, 2, 1, 15, 14, 13, 12
data inputs
Y
5
multiplexer output
Y
6
complementary multiplexer output
OE
7
output enable input (active LOW)
GND
8
ground (0 V)
S0, S1, S2
11, 10, 9
common data select inputs
VCC
16
supply voltage
74HC_HCT251
Product data sheet
All information provided in this document is subject to legal disclaimers.
Rev. 4 — 1 February 2016
© NXP Semiconductors N.V. 2016. All rights reserved.
3 of 18
74HC251; 74HCT251
NXP Semiconductors
8-input multiplexer; 3-state
6. Functional description
Function table[1]
Table 3.
Input
Output
OE
S2
H
X
X
X
X
X
X
X
X
X
X
X
Z
Z
L
L
L
L
L
X
X
X
X
X
X
X
H
L
L
L
L
L
H
X
X
X
X
X
X
X
L
H
L
L
L
H
X
L
X
X
X
X
X
X
H
L
L
L
L
H
X
H
X
X
X
X
X
X
L
H
L
L
H
L
X
X
L
X
X
X
X
X
H
L
L
L
H
L
X
X
H
X
X
X
X
X
L
H
L
L
H
H
X
X
X
L
X
X
X
X
H
L
L
L
H
H
X
X
X
H
X
X
X
X
L
H
L
H
L
L
X
X
X
X
L
X
X
X
H
L
L
H
L
L
X
X
X
X
H
X
X
X
L
H
L
H
L
H
X
X
X
X
X
L
X
X
H
L
L
H
L
H
X
X
X
X
X
H
X
X
L
H
L
H
H
L
X
X
X
X
X
X
L
X
H
L
L
H
H
L
X
X
X
X
X
X
H
X
L
H
L
H
H
H
X
X
X
X
X
X
X
L
H
L
L
H
H
H
X
X
X
X
X
X
X
H
L
H
[1]
S1
S0
I0
I1
I2
I3
I4
I5
I6
I7
Y
Y
H = HIGH voltage level; L = LOW voltage level; X = don’t care; Z = high-impedance OFF-state.
7. Limiting values
Table 4.
Limiting values
In accordance with the Absolute Maximum Rating System (IEC 60134). Voltages are referenced to GND (ground = 0 V).
Symbol
Parameter
Conditions
VCC
supply voltage
IIK
input clamping current
IOK
output clamping current
VO < 0.5 V or VO > VCC + 0.5 V
-
20
mA
IO
output current
VO = 0.5 V to (VCC + 0.5 V)
-
25
mA
ICC
supply current
-
+50
mA
IGND
ground current
50
-
mA
Tstg
storage temperature
65
+150
C
Ptot
total power dissipation
VI < 0.5 V or VI > VCC + 0.5 V
Unit
0.5
+7
V
-
20
mA
SO16 package
[1]
-
500
mW
(T)SSOP16 package
[2]
-
500
mW
For SO16 package: Ptot derates linearly with 8 mW/K above 70 C.
[2]
For SSOP16 and TSSOP16 packages: Ptot derates linearly with 5.5 mW/K above 60 C.
Product data sheet
Max
Tamb = 40 C to +125 C
[1]
74HC_HCT251
Min
All information provided in this document is subject to legal disclaimers.
Rev. 4 — 1 February 2016
© NXP Semiconductors N.V. 2016. All rights reserved.
4 of 18
74HC251; 74HCT251
NXP Semiconductors
8-input multiplexer; 3-state
8. Recommended operating conditions
Table 5.
Recommended operating conditions
Voltages are referenced to GND (ground = 0 V)
Symbol Parameter
Conditions
74HC251
74HCT251
Unit
Min
Typ
Max
Min
Typ
Max
2.0
5.0
6.0
4.5
5.0
5.5
V
input voltage
0
-
VCC
0
-
VCC
V
output voltage
0
-
VCC
0
-
VCC
V
VCC
supply voltage
VI
VO
Tamb
ambient temperature
t/V
input transition rise and fall rate
40
+25
+125
40
+25
+125
VCC = 2.0 V
-
-
625
-
-
-
ns/V
C
VCC = 4.5 V
-
1.67
139
-
1.67
139
ns/V
VCC = 6.0 V
-
-
83
-
-
-
ns/V
9. Static characteristics
Table 6.
Static characteristics
At recommended operating conditions; voltages are referenced to GND (ground = 0 V).
Symbol Parameter
Tamb = 25 C
Conditions
Min
Typ
Tamb = 40 C to
+85 C
Max
Min
Max
Tamb = 40 C to Unit
+125 C
Min
Max
74HC251
VIH
VIL
VOH
VOL
HIGH-level
input voltage
LOW-level
input voltage
HIGH-level
output voltage
LOW-level
output voltage
VCC = 2.0 V
1.5
1.2
-
1.5
-
1.5
-
V
VCC = 4.5 V
3.15
2.4
-
3.15
-
3.15
-
V
VCC = 6.0 V
4.2
3.2
-
4.2
-
4.2
-
V
VCC = 2.0 V
-
0.8
0.5
-
0.5
-
0.5
V
VCC = 4.5 V
-
2.1
1.35
-
1.35
-
1.35
V
VCC = 6.0 V
-
2.8
1.8
-
1.8
-
1.8
V
IO = 20 A; VCC = 2.0 V
1.9
2.0
-
1.9
-
1.9
-
V
IO = 20 A; VCC = 4.5 V
4.4
4.5
-
4.4
-
4.4
-
V
IO = 20 A; VCC = 6.0 V
5.9
6.0
-
5.9
-
5.9
-
V
IO = 4.0 mA; VCC = 4.5 V
3.98
4.32
-
3.84
-
3.7
-
V
IO = 5.2 mA; VCC = 6.0 V
5.48
5.81
-
5.34
-
5.2
-
V
IO = 20 A; VCC = 2.0 V
-
0
0.1
-
0.1
-
0.1
V
IO = 20 A; VCC = 4.5 V
-
0
0.1
-
0.1
-
0.1
V
IO = 20 A; VCC = 6.0 V
-
0
0.1
-
0.1
-
0.1
V
IO = 4.0 mA; VCC = 4.5 V
-
0.15
0.26
-
0.33
-
0.4
V
IO = 5.2 mA; VCC = 6.0 V
-
0.16
0.26
-
0.33
-
0.4
V
VI = VIH or VIL
VI = VIH or VIL
II
input leakage
current
VI = VCC or GND;
VCC = 6.0 V
-
-
0.1
-
1.0
-
1.0
A
IOZ
OFF-state
output current
VI = VIH or VIL;
VO = VCC or GND;
VCC = 6.0 V
-
-
0.5
-
5.0
-
10.0
A
74HC_HCT251
Product data sheet
All information provided in this document is subject to legal disclaimers.
Rev. 4 — 1 February 2016
© NXP Semiconductors N.V. 2016. All rights reserved.
5 of 18
74HC251; 74HCT251
NXP Semiconductors
8-input multiplexer; 3-state
Table 6.
Static characteristics …continued
At recommended operating conditions; voltages are referenced to GND (ground = 0 V).
Tamb = 25 C
Symbol Parameter
Conditions
ICC
supply current
VI = VCC or GND; IO = 0 A;
VCC = 6.0 V
CI
input
capacitance
Min
Tamb = 40 C to
+85 C
Tamb = 40 C to Unit
+125 C
Typ
Max
Min
Max
Min
Max
-
-
8.0
-
80
-
160
-
3.5
-
A
pF
74HCT251
VIH
HIGH-level
input voltage
VCC = 4.5 V to 5.5 V
2.0
1.6
-
2.0
-
2.0
-
V
VIL
LOW-level
input voltage
VCC = 4.5 V to 5.5 V
-
1.2
0.8
-
0.8
-
0.8
V
VOH
HIGH-level
output voltage
VI = VIH or VIL; VCC = 4.5 V
IO = 20 A
4.4
4.5
-
4.4
-
4.4
-
V
IO = 4 mA
3.98
4.32
-
3.84
-
3.7
-
V
LOW-level
output voltage
VI = VIH or VIL; VCC = 4.5 V
IO = 20 A
-
0
0.1
-
0.1
-
0.1
V
IO = 4.0 mA
-
0.15
0.26
-
0.33
-
0.4
V
VOL
II
input leakage
current
VI = VCC or GND;
VCC = 5.5 V
-
-
0.1
-
1.0
-
1.0
A
IOZ
OFF-state
output current
VI = VIH or VIL;
VO = VCC or GND;
VCC = 5.5 V
-
-
0.5
-
5.0
-
10
A
ICC
supply current
VI = VCC or GND; IO = 0 A;
VCC = 5.5 V
-
-
8.0
-
80
-
160
A
ICC
additional
supply current
VI = VCC 2.1 V;
other inputs at VCC or GND;
VCC = 4.5 V to 5.5 V;
IO = 0 A
-
100
360
-
450
-
490
A
per input pin; In inputs
CI
input
capacitance
74HC_HCT251
Product data sheet
per input pin; OE input
-
150
540
-
675
-
735
A
per input pin; Sn input
-
150
540
-
675
-
735
A
-
3.5
-
All information provided in this document is subject to legal disclaimers.
Rev. 4 — 1 February 2016
pF
© NXP Semiconductors N.V. 2016. All rights reserved.
6 of 18
74HC251; 74HCT251
NXP Semiconductors
8-input multiplexer; 3-state
10. Dynamic characteristics
Table 7.
Dynamic characteristics
Voltages are referenced to GND (ground = 0 V); CL = 50 pF unless otherwise specified; for test circuit, see Figure 9.
Symbol Parameter
Tamb = 25 C
Conditions
Tamb = 40 C
to +85 C
Tamb = 40 C
to +125 C
Min
Typ
Max
Min
Max
Min
Max
Unit
74HC251
tpd
propagation
delay
In to Y; see Figure 6
[1]
VCC = 2.0 V
-
50
170
-
215
-
255
ns
VCC = 4.5 V
-
18
34
-
43
-
51
ns
VCC = 5 V; CL = 15 pF
-
15
-
-
-
-
-
ns
-
14
29
-
37
-
43
ns
VCC = 2.0 V
-
55
175
-
220
-
265
ns
VCC = 4.5 V
-
20
35
-
44
-
53
ns
VCC = 5 V; CL = 15 pF
-
17
-
-
-
-
-
ns
-
16
30
-
37
-
45
ns
VCC = 2.0 V
-
66
205
-
255
-
310
ns
VCC = 4.5 V
-
24
41
-
51
-
62
ns
VCC = 6.0 V
In to Y; see Figure 6
[1]
VCC = 6.0 V
Sn to Y; see Figure 7
[1]
VCC = 5 V; CL = 15 pF
-
20
-
-
-
-
-
ns
VCC = 6.0 V
-
19
35
-
43
-
53
ns
VCC = 2.0 V
-
69
205
-
255
-
310
ns
VCC = 4.5 V
-
25
41
-
51
-
62
ns
VCC = 5 V; CL = 15 pF
-
21
-
-
-
-
-
ns
-
20
35
-
43
-
53
ns
VCC = 2.0 V
-
36
140
-
175
-
210
ns
VCC = 4.5 V
-
13
28
-
35
-
42
ns
-
10
24
-
30
-
36
ns
VCC = 2.0 V
-
39
140
-
170
-
210
ns
VCC = 4.5 V
-
14
28
-
35
-
42
ns
-
11
24
-
30
-
36
ns
VCC = 2.0 V
-
19
75
-
95
-
110
ns
VCC = 4.5 V
-
7
15
-
19
-
22
ns
-
6
13
-
16
-
19
ns
-
44
-
-
-
-
-
pF
Sn to Y; see Figure 7
[1]
VCC = 6.0 V
ten
enable time
OE to Y, Y; see Figure 7
[2]
VCC = 6.0 V
tdis
disable time OE to Y, Y; see Figure 7
[3]
VCC = 6.0 V
tt
transition
time
[4]
Y, Y; see Figure 6
VCC = 6.0 V
CPD
power
dissipation
capacitance
74HC_HCT251
Product data sheet
CL = 50 pF; f = 1 MHz;
VI = GND to VCC
[5]
All information provided in this document is subject to legal disclaimers.
Rev. 4 — 1 February 2016
© NXP Semiconductors N.V. 2016. All rights reserved.
7 of 18
74HC251; 74HCT251
NXP Semiconductors
8-input multiplexer; 3-state
Table 7.
Dynamic characteristics …continued
Voltages are referenced to GND (ground = 0 V); CL = 50 pF unless otherwise specified; for test circuit, see Figure 9.
Symbol Parameter
Tamb = 25 C
Conditions
Tamb = 40 C
to +85 C
Tamb = 40 C
to +125 C
Unit
Min
Typ
Max
Min
Max
Min
Max
-
22
35
-
44
-
53
ns
-
19
-
-
-
-
-
ns
-
22
35
-
44
-
53
ns
-
19
-
-
-
-
-
ns
-
24
44
-
55
-
66
ns
-
20
-
-
-
-
-
ns
VCC = 4.5 V
-
25
44
-
55
-
66
ns
VCC = 5 V; CL = 15 pF
-
21
-
-
-
-
-
ns
-
13
28
-
35
-
42
ns
-
13
-
-
-
-
-
ns
-
14
28
-
35
-
42
ns
-
18
-
-
-
-
-
ns
-
7
15
-
19
-
22
ns
-
46
-
-
-
-
-
pF
74HCT251
propagation
delay
tpd
[1]
In to Y; see Figure 6
VCC = 4.5 V
VCC = 5 V; CL = 15 pF
[1]
In to Y; see Figure 6
VCC = 4.5 V
VCC = 5 V; CL = 15 pF
[1]
Sn to Y; see Figure 7
VCC = 4.5 V
VCC = 5 V; CL = 15 pF
[1]
Sn to Y; see Figure 7
enable time
ten
[2]
OE to Y, Y; see Figure 7
VCC = 4.5 V
VCC = 5 V; CL = 15 pF
[3]
disable time OE to Y, Y; see Figure 7
tdis
VCC = 4.5 V
VCC = 5 V; CL = 15 pF
transition
time
tt
power
dissipation
capacitance
CPD
[1]
[4]
Y, Y; see Figure 6
VCC = 4.5 V
[5]
CL = 50 pF; f = 1 MHz;
VI = GND to VCC
tpd is the same as tPLH and tPHL.
[2]
ten is the same as tPZH and tPZL.
[3]
tdis is the same as tPLZ and tPHZ.
[4]
tt is the same as tTHL and tTLH.
[5]
CPD is used to determine the dynamic power dissipation (PD in W).
PD = CPD VCC2 fi N + (CL VCC2 fo) where:
fi = input frequency in MHz;
fo = output frequency in MHz;
CL = output load capacitance in pF;
VCC = supply voltage in V;
N = number of inputs switching;
(CL VCC2 fo) = sum of outputs.
74HC_HCT251
Product data sheet
All information provided in this document is subject to legal disclaimers.
Rev. 4 — 1 February 2016
© NXP Semiconductors N.V. 2016. All rights reserved.
8 of 18
74HC251; 74HCT251
NXP Semiconductors
8-input multiplexer; 3-state
11. Waveforms
9,
90
,QLQSXW
90
*1'
W3+/
92+
W3/+
90