74280 IC 9-bit odd/even parity generator/checker

74280 IC 9-bit odd/even
parity generator
/checker

The 74LS280 is a universal 9-bit parity generator and checker designed for high-performance digital systems. It features both odd and even outputs, allowing it to facilitate either parity type with ease. While it is designed without a traditional expander input, it can be easily cascaded to handle longer word lengths. This model is an ideal upgrade for systems using older MSI parity circuits, such as the LS180, offering improved performance and lower drive requirements through its buffered inputs.

Features

9-Bit Parity Support:
Generates either odd or even parity for nine data lines.

Universal Application:
Features dedicated EVEN and ODD outputs.

High Speed:
Typical data-to-output propagation delay of 33 ns.

Low Loading:
Inputs are buffered to lower drive requirements to just one LS unit load.

Low Power:
Typical power dissipation is only 80 mW.

Cascadable:
Designed for easy word-length expansion for n-bit systems.

System Upgrade:
Direct performance-enhancing substitute for older MSI circuits like the LS180.

Specifications

Guaranteed Operating Ranges

Symbol

Parameter

Min

Typ

Max

Unit

Vcc

Supply Voltage

4.75

5.0

5.25

V

Ta

Operating Ambient Temperature

0

25

70

C

Ioh

Output Current High

-0.4

mA

Iol

Output Current Low

8.0

mA

DC Characteristics

Symbol

Parameter

Min

Typ

Max

Unit

Test Conditions

Vih

Input HIGH Voltage

2.0

V

Guaranteed for all inputs

Vil

Input LOW Voltage

0.8

V

Guaranteed for all inputs

Vik

Input Clamp Diode Voltage

-0.65

-1.5

V

Vcc=MIN, Iin=-18mA

Voh

Output HIGH Voltage

2.7

3.5

V

Vcc=MIN, Ioh=MAX

Vol

Output LOW Voltage

0.35

0.5

V

Vcc=MIN, Iol=8.0mA

Iih

Input HIGH Current

20

A

Vcc=MAX, Vin=2.7V

Iil

Input LOW Current

-0.4

mA

Vcc=MAX, Vin=0.4V

Icc

Power Supply Current

27

mA

Vcc=MAX

AC Switching Characteristics

Conditions: Ta = 25C, Vcc = 5.0V, Cl = 15pF

Symbol

Parameter

Typ

Max

Unit

tplh / tphl

Propagation Delay (Data to EVEN)

33 / 29

50 / 45

ns

tplh / tphl

Propagation Delay (Data to ODD)

23 / 31

35 / 50

ns

Applications

Error Detection

Parity Generation

System Upgrades

Word Length Expansion

Package Content

1 x 74280 IC 9-bit odd/even parity generator/checker

DataSheet

74LS280