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/HCT280
9-bit odd/even parity
generator/checker
Product specification
File under Integrated Circuits, IC06
December 1990
Philips Semiconductors Product specification
9-bit odd/even parity generator/checker 74HC/HCT280
FEATURES
• Word-length easily expanded by cascading
• Similar pin configuration to the “180” for easy system
up-grading
• Generates either odd or even parity for nine data bits
• Output capability: standard
• ICC category: MSI
transmission or data retrieval systems. Both even and odd
parity outputs are available for generating or checking
even or odd parity up to 9 bits.
The even parity output (∑
of data inputs (I0 to I8) are HIGH. The odd parity output (∑0)
is HIGH when an odd number of data inputs are HIGH.
Expansion to larger word sizes is accomplished by tying
the even outputs (∑E) of up to nine parallel devices to the
data inputs of the final stage. For a single-chip 16-bit
GENERAL DESCRIPTION
even/odd parity generator/checker, see
PC74HC/HCT7080.
The 74HC/HCT280 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/HCT280 are 9-bit parity generators or checkers
APPLICATIONS
• 25-line parity generator/checker
• 81-line parity generator/checker
commonly used to detect errors in high-speed data
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 CL= 15 pF; VCC=5 V
PLH
I
to ∑
n
E
I
to ∑
n
O
input capacitance 3.5 3.5 pF
power dissipationcapacitance per package notes 1 and 2 65 65 pF
) is HIGH when an even number
E
TYPICAL
UNIT
HC HCT
17 18 ns
20 22 ns
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
“74HC/HCT/HCU/HCMOS Logic Package Information”
See
December 1990 2
.
Philips Semiconductors Product specification
9-bit odd/even parity generator/checker 74HC/HCT280
PIN DESCRIPTION
PIN NO. SYMBOL NAME AND FUNCTION
8, 9, 10, 11, 12, 13, 1, 2, 4 I
5, 6 ∑
7 GND ground (0 V)
14 V
to I
0
E
CC
, ∑
8
O
data inputs
parity outputs
positive supply voltage
Fig.1 Pin configuration. Fig.2 Logic symbol. Fig.3 IEC logic symbol.
December 1990 3