HD74LS22 Dual 4-Input NAND Gates IC DIP-14

The 74×22 (ex 74LS22) is a chip that comes packed with two 4-input open-collector NAND gates. The benefit of an open collector output is that it facilitates connections with chips utilizing varied logic levels, but remember, it’s not interchangeable with a typical NAND gate chip.

Learn how it works and how to use it with this beginner-friendly guide and start using NAND gates in your projects.

What does the 74HC22 / 74LS22 do?

The 74×22 gives you two 4-input open-collector NAND gates that you can use individually. A NAND gate is a logic gate that outputs 0 (LOW) only if all of its inputs are 1 (HIGH).

How To Use This Chip

The 74HC22 comes in a 14-pin package, and you need to connect its power pins before you can use it. Most 7400 ICs support a VCC voltage of 5V. One difference between the HC and LS version of the chip is that the 74HC22 supports 2V to 6V, while the 74LS22 only supports 5V.

This chip uses open-collector outputs which means you can only sink current, not source it.

The output of each gate in the 74HC22 can sink around 4 milliamps when it’s powered with 5 volts. On the other hand, the 74LS22 can usually handle about 8 milliamps of current. But, these values might differ depending on the chip manufacturer.

74×22 Pinout

The 74×22 has 14 pins and contains two 4-input open-collector NAND gates laid out as shown in the pinout diagram below: