Page 1
INTEGRATED CIRCUITS
DATA SH EET
For a complete data sheet, please also download:
•The IC06 74HC/HCT/HCU/HCMOS Logic Family Specifications
•The IC06 74HC/HCT/HCU/HCMOS Logic Package Information
•The IC06 74HC/HCT/HCU/HCMOS Logic Package Outlines
74HC/HCT7540
Octal Schmitt trigger buffer/line
driver; 3-state; inverting
Product specification
Supersedes data of March 1988
File under Integrated Circuits, IC06
December 1990
Page 2
Philips Semiconductors Product specification
Octal Schmitt trigger buffer/line driver;
3-state; inverting
FEATURES
• Inverting outputs
• Schmitt trigger action on all data inputs
• Output capability: bus driver
• ICC category: MSI
GENERAL DESCRIPTION
The 74HC/HCT7540 are high-speed Si-gate CMOS
devices and are pin compatible with low power Schottky
TTL (LSTTL). They are specified in compliance with
JEDEC standard no. 7A.
QUICK REFERENCE DATA
GND = 0 V; T
=25°C; tr=tf= 6 ns
amb
SYMBOL PARAMETER CONDITIONS
t
PHL
C
C
/ t
I
PD
propagation delay An to Y
PLH
n
input capacitance 3.5 3.5 pF
power dissipation capacitance per buffer notes 1 and 2 29 31 pF
The 74HC/HCT7540 are octal Schmitt trigger inverting
buffer/line drivers with 3-state outputs. The 3-state outputs
are controlled by the output enable inputs
A HIGH on OEn causes the outputs to assume a high
impedance OFF-state.
The Schmitt trigger action in the data inputs transforms
slowly changing input signals into sharply defined
jitter-free output signals.
The “7540” is identical to the “540” but has hysteresis on
the data inputs.
CL= 15 pF; VCC=5 V 11 16 ns
74HC/HCT7540
OE1 and OE2.
TYPICAL
UNIT
HC HCT
Notes
1. C
is used to determine the dynamic power dissipation (PD in µW):
PD
PD=CPD× V
2
× fi+∑(CL× V
CC
2
× fo) where:
CC
fi= input frequency in MHz
fo= output frequency in MHz
∑ (CL× V
2
× fo) = sum of outputs
CC
CL= output load capacitance in pF
VCC= supply voltage in V
2. For HC the condition is VI= GND to V
CC
For HCT the condition is VI= GND to VCC− 1.5 V
ORDERING INFORMATION
See
“74HC/HCT/HCU/HCMOS Logic Package Information”
.
December 1990 2
Page 3
Philips Semiconductors Product specification
Octal Schmitt trigger buffer/line driver;
3-state; inverting
PIN DESCRIPTION
PIN NO. SYMBOL NAME AND FUNCTION
1, 19
2, 3, 4, 5, 6, 7, 8, 9 A
10 GND ground (0 V)
18, 17, 16, 15, 14, 13, 12, 11
20 V
OE1, OE
to A
0
Y0 to Y
CC
2
7
7
output enable inputs (active LOW)
data inputs
bus outputs
positive supply voltage
74HC/HCT7540
Fig.1 Pin configuration. Fig.2 Logic symbol. Fig.3 IEC logic symbol.
December 1990 3
Page 4
Philips Semiconductors Product specification
Octal Schmitt trigger buffer/line driver;
3-state; inverting
FUNCTION TABLE
INPUTS OUTPUTS
OE
1
L
L
X
H
Notes
1. H = HIGH voltage level
L = LOW voltage level
X = don’t care
Z = high impedance OFF-state
OE
H
X
2
L
L
A
n
L
H
X
X
Y
n
H
L
Z
Z
74HC/HCT7540
Fig.4 Functional diagram.
Fig.5 Logic diagram.
December 1990 4
Page 5
Philips Semiconductors Product specification
Octal Schmitt trigger buffer/line driver;
3-state; inverting
DC CHARACTERISTICS FOR 74HC
For the DC characteristics see
Transfer characteristics are given below (not applicable for OEn inputs).
Output capability: bus driver
ICC category: MSI
AC CHARACTERISTICS FOR 74HC
GND = 0 V; tr=tf= 6 ns; CL= 50 pF
SYMBOL PARAMETER
t
PHL
t
PZH
/ t
/ t
propagation delay
PLH
An to Y
3-state output enable
PZL
n
time
t
PHZ
OEn to Y
/ t
3-state output disable
PLZ
n
time
t
THL
OEn to Y
/ t
output transition time 14
TLH
n
“74HC/HCT/HCU/HCMOS Logic Family Specifications”
T
(°C)
amb
74HC
min. typ. max. min. max. min. max.
39
14
11
41
15
12
52
19
15
5
4
120
24
20
150
30
26
150
30
26
60
12
10
150
30
26
190
38
33
190
38
33
75
15
13
180
36
31
225
45
38
225
45
38
90
18
15
74HC/HCT7540
.
TEST CONDITIONS
UNIT
ns 2.0
ns 2.0
ns 2.0
ns 2.0
V
(V)
4.5
6.0
4.5
6.0
4.5
6.0
4.5
6.0
CC
WAVEFORMS+25 −40 to +85 −40 to +125
Fig.8
Fig.9
Fig.9
Fig.8
TRANSFER CHARACTERISTICS FOR 74HC
Voltages are referred to GND (ground = 0 V)
SYMBOL PARAMETER
min. typ. max. min. max. min. max.
V
T+
positive-going threshold 1.50
3.15
4.20
V
T−
negative-going threshold 0.30
1.35
1.80
V
H
hysteresis (VT+− VT−) 0.10
0.25
0.30
0.20
0.40
0.50
December 1990 5
T
amb
0.30
1.35
1.80
0.10
0.25
0.30
(°C)
74HC
1.50
3.15
4.20
0.30
1.35
1.80
0.10
0.25
0.30
1.50
3.15
4.20
TEST CONDITIONS
UNIT
V
CC
(V)
V 2.0
4.5
6.0
V 2.0
4.5
6.0
V 2.0
4.5
6.0
WAVEFORMS+25 −40 to +85 −40 to +125
Figs 6 and 7
Figs 6 and 7
Figs 6 and 7
Page 6
Philips Semiconductors Product specification
Octal Schmitt trigger buffer/line driver;
74HC/HCT7540
3-state; inverting
DC CHARACTERISTICS FOR 74HCT
For the DC characteristics see
Transfer characteristics are given below (not applicable for OEn inputs).
Output capability: bus driver
ICC category: MSI
Note to HCT types
The value of additional quiescent supply current (∆ICC) for a unit load of 1 is given in the family specifications.
To determine ∆I
per input, multiply this value by the unit load coefficient shown in the table below.
CC
INPUT UNIT LOAD
OE
OE
A
1
2
n
1.30
1.30
0.20
AC CHARACTERISTICS FOR 74HCT
GND = 0 V; t
= 6 ns; CL= 50 pF
r=tf
SYMBOL PARAMETER
t
PHL
t
PZH
t
PHZ
t
THL
/ t
/ t
/ t
/ t
propagation delay
PLH
An to Y
n
3-state output enable time
PZL
OEn to Y
3-state output disable time
PLZ
OEn to Y
output transition time 5 12 15 18 ns 4.5 Fig.8
TLH
n
n
“74HC/HCT/HCU/HCMOS Logic Family Specifications”
(°C)
T
amb
74HCT
min typ. max. min max. min. max.
19 32 40 48 ns 4.5 Fig.8
19 32 40 48 ns 4.5 Fig.9
20 32 40 48 ns 4.5 Fig.9
.
UNIT
TEST CONDITIONS
V
CC
WAVEFORMS+25 −40 to +85 −40 to +125
(V)
TRANSFER CHARACTERISTICS FOR 74HCT
Voltages are referred to GND (ground = 0 V)
SYMBOL PARAMETER
min typ. max. min max. min. max.
V
T+
positive-going threshold 2.0
2.1
V
T−
negative-going threshold 0.70
0.80
V
H
hysteresis (VT+− VT−) 0.17
0.17
0.23
0.23
December 1990 6
T
amb
74HCT
0.64
0.74
(°C)
2.0
2.1
0.60
0.70
2.0
2.1
TEST CONDITIONS
UNIT
V
(V)
V 4.5
5.5
V 4.5
5.5
V 4.5
5.5
CC
WAVEFORMS+25 −40 to +85 −40 to +125
Figs 6 and 7
Figs 6 and 7
Figs 6 and 7
Page 7
Philips Semiconductors Product specification
Octal Schmitt trigger buffer/line driver;
3-state; inverting
TRANSFER CHARACTERISTIC WAVEFORMS
Fig.6 Transfer characteristic.
AC WAVEFORMS
74HC/HCT7540
Fig.7 Waveforms showing the definition of VT+,
VT− and VH.
(1) HC : VM= 50%; VI= GND to VCC.
= 1.3 V; VI= GND to 3 V.
HCT: V
M
Fig.8 Waveforms showing the input (An) to output (Yn) propagation delays and the output transition times.
(1) HC : VM= 50%; VI= GND to VCC.
= 1.3 V; VI= GND to 3 V.
HCT: V
M
Fig.9 Waveforms showing the 3-state enable and disable times.
PACKAGE OUTLINES
“74HC/HCT/HCU/HCMOS Logic Package Outlines”
See
.
December 1990 7
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