Page 1
DATA SH EET
Product specification
File under Integrated Circuits, IC06
December 1990
INTEGRATED CIRCUITS
74HC/HCT42
BCD to decimal decoder (1-of-10)
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
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December 1990 2
Philips Semiconductors Product specification
BCD to decimal decoder (1-of-10) 74HC/HCT42
FEATURES
• Mutually exclusive outputs
• 1-of-8 demultiplexing capability
• Outputs disabled for input codes above nine
• Output capability: standard
• ICC category: MSI
GENERAL DESCRIPTION
The 74HC/HCT42 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.
The 74HC/HCT42 decoders accept four active HIGH BCD
inputs and provide 10 mutually exclusive active LOW
outputs. The active LOW outputs facilitate addressing
other MSI circuits with active LOW input enables.
The logic design of the “42” ensures that all outputs are
HIGH when binary codes greater than nine are applied to
the inputs.
The most significant input (A
3
) produces an useful inhibit
function when the “42” is used as a 1-of-8 decoder. The A
3
input can also be used as the data input in an 8-output
demultiplexer application.
QUICK REFERENCE DATA
GND = 0 V; T
amb
=25°C; tr=tf= 6 ns
Notes
1. C
PD
is used to determine the dynamic power dissipation (PD in µW):
PD=CPD × V
CC
2
× fi+∑(CL× V
CC
2
× fo) where:
fi= input frequency in MHz
fo= output frequency in MHz
∑ (CL× V
CC
2
× fo) = sum of outputs
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”
.
SYMBOL PARAMETER CONDITIONS
TYPICAL
UNIT
HC HCT
t
PHL
/ t
PLH
propagation delay Anto Y
n
CL= 15 pF; VCC= 5 V 14 17 ns
C
I
input capacitance 3.5 3.5 pF
C
PD
power dissipation capacitance per package notes 1 and 2 37 37 pF
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December 1990 3
Philips Semiconductors Product specification
BCD to decimal decoder (1-of-10) 74HC/HCT42
PIN DESCRIPTION
PIN NO. SYMBOL NAME AND FUNCTION
1, 2, 3, 4, 5, 6, 7, 9, 10, 11
Y0 to Y
9
multiplexer outputs
8 GND ground (0 V)
15, 14, 13, 12 A
0
to A
3
data inputs
16 V
CC
positive supply voltage
Fig.1 Pin configuration. Fig.2 Logic symbol. Fig.3 IEC logic symbol.
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December 1990 4
Philips Semiconductors Product specification
BCD to decimal decoder (1-of-10) 74HC/HCT42
Fig.4 Functional diagram.
FUNCTION TABLE
Note
1. H = HIGH voltage level
L = LOW voltage level
INPUTS OUTPUTS
A3A2A1A0Y0Y1Y2Y3Y4Y5Y6Y7Y8Y
9
L
L
L
L
L
L
L
L
L
L
H
H
L
H
L
H
L
H
H
H
H
L
H
H
H
H
L
H
H
H
H
L
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
L
L
L
L
H
H
H
H
L
L
H
H
L
H
L
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
L
H
H
H
H
L
H
H
H
H
L
H
H
H
H
L
H
H
H
H
H
H
H
H
H
H
H
H
L
L
L
L
L
L
H
H
L
H
L
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
L
H
H
H
H
L
H
H
H
H
H
H
H
H
H
H
L
L
H
H
L
H
L
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
Fig.5 Logic diagram.
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December 1990 5
Philips Semiconductors Product specification
BCD to decimal decoder (1-of-10) 74HC/HCT42
DC CHARACTERISTICS FOR 74HC
For the DC characteristics see
“74HC/HCT/HCU/HCMOS Logic Family Specifications”
.
Output capability: standard
ICC category: MSI
AC CHARACTERISTICS FOR 74HC
GND = 0 V; t
r=tf
= 6 ns; CL= 50 pF
DC CHARACTERISTICS FOR 74HCT
For the DC characteristics see
“74HC/HCT/HCU/HCMOS Logic Family Specifications”
.
Output capability: standard
ICC category: MSI
Note to HCT types
The value of additional quiescent supply current (∆I
CC
) for a unit load of 1 is given in the family specifications.
To determine ∆ICC per input, multiply this value by the unit load coefficient shown in the table below.
AC CHARACTERISTICS FOR 74HCT
GND = 0 V; t
r=tf
= 6 ns; CL= 50 pF
SYMBOL PARAMETER
T
amb
(°C) TEST CONDITIONS
74HC
UNIT
V
CC
(V)
WAVEFORMS
+25 −40 to +85 −40 to +125
min. typ. max. min. max. min. max.
t
PHL
/ t
PLH
propagation delay
Anto Y
n
47
17
14
150
30
26
190
38
33
225
45
38
ns 2.0
4.5
6.0
Fig.6
t
THL
/ t
TLH
output transition time 19
7
6
75
15
13
95
19
16
110
22
19
ns 2.0
4.5
6.0
Fig.6
INPUT UNIT LOAD COEFFICIENT
A
n
1.0
SYMBOL PARAMETER
T
amb
(°C) TEST CONDITIONS
74HCT
UNIT
V
CC
(V)
WAVEFORMS
+25 −40 to +85 −40 to +125
min. typ. max. min. max. min. max.
t
PHL
/ t
PLH
propagation delay
Anto Y
n
20 35 44 53 ns 4.5 Fig.6
t
THL
/ t
TLH
output transition time 7 15 19 22 ns 4.5 Fig.6
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December 1990 6
Philips Semiconductors Product specification
BCD to decimal decoder (1-of-10) 74HC/HCT42
AC WAVEFORMS
PACKAGE OUTLINES
See
“74HC/HCT/HCU/HCMOS Logic Package Outlines”
.
Fig.6 Waveforms showing the input (An) to output (Yn) propagation delays and the output transition times.
(1) HC : VM= 50%; VI= GND to VCC.
HCT: V
M
= 1.3 V; VI= GND to 3 V.
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