The MC74HC280 is identical in pinout to the LS280. The device inputs are compatible with standard CMOS outputs; with pullup resistors, they are compatible with LSTTL outputs.

This circuit consists of 9 data–bit inputs (A through I) and 2 outputs (Even Parity and Odd Parity) to allow both odd and even parity applications. Words greater than 9–bits can be accommodated by cascading other HC280 devices.

This device can be used in systems utilizing the LS180 parity generator/checker. Although the HC280 does not have expander inputs, the corresponding function is provided by an input at pin 4 and the absence of any connection at pin 3. This permits the HC280 to be substituted for the LS180 to produce a similar function, even if the HC280s are mixed with existing LS180s. NOTE: Pullup resistors must be used on the LS180 outputs

to interface with the HC280.

• Output Drive Capability: 10 LSTTL Loads

• Outputs Directly Interface to CMOS, NMOS, and TTL

• Operating Voltage Range: 2 to 6 V

• Low Input Current: 1 µA

• High Noise Immunity Characteristic of CMOS Devices

• In Compliance with the Requirements Defined by JEDEC Standard No. 7A

• Chip Complexity: 226 FETs or 56.5 Equivalent Gates