7400 Series Guide: 74HC04/74LS04 (NOT gates)

This IC, often found as 74LS04 or 74HC04, is a chip with six NOT gates – or inverters. The NOT gate is a logic gate that always gives you the opposite of what you put in. It is one of the most basic building blocks in digital electronics and comes in a 14-pin package with the following pinout:

In this guide, you will learn what the 74×04 IC does and how to hook it up in a circuit.

What does the 74HC04 / 74LS04 do?

The 74×04 gives you six inverters that can be used individually. A NOT gate (or inverter) is a logic gate that outputs the opposite of the input. In the truth table below, you can see what the output will be for any given input:

How To Use This Chip

Like every other chip in the 7400 series, this IC must be connected to power 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 74HC04 supports 2V to 6V, while the 74LS04 supports only 5V.

Once it’s connected, you can use any of the six inverters inside.

Output Current

74HC04:
Each gate output of the 74HC04 can sink or source 4 mA when powered with 5V.

74LS04:
HIGH-Level Output Current: 0.4 mA
LOW-Level Output Current: 8 mA

74×04 Pinout

The 74×04 has 14 pins and contains six inverters laid out as shown in the pinout diagram below:

Pin Name	Pin #	Type	Description
1A	1	Input	Input to the first NOT gate.
1Y	2	Output	Output from the first NOT gate.
2A	3	Input	Input to the second NOT gate.
2Y	4	Output	Output from the second NOT gate.
3A	5	Input	Input to the third NOT gate.
3Y	6	Output	Output from the third NOT gate.
GND	7	Power	Connect to ground.
4Y	8	Input	Output from the fourth NOT gate.
4A	9	Output	Input to the fourth NOT gate.
5Y	10	Input	Output from the fifth NOT gate.
5A	11	Output	Input to the fifth NOT gate.
6Y	12	Input	Output from the sixth NOT gate.
6A	13	Output	Input to the sixth NOT gate.
VCC	14	Power	Positive power supply. Connect to +5V power.

74×04 Circuit Example

A NOT gate can be used for a zillion different things. For example, you can convert an AND gate into a NAND gate, like this:

Or you could convert an OR gate into a NOR gate, like this:

Alternatives and Equivalents for 74HC04 / 74LS04

There are many versions of the 74×04 chip. They all have the same functionality but with different specifications such as supported voltages and maximum current output.

Here’s a list of a few equivalents of this chip:

• 74HC04 (High-speed CMOS)
• 74HCT04 (High-speed CMOS, TTL compatible)
• 74LS04 (High-speed TTL)
• 74LVC04 (Low Voltage TTL)
• 74AC04 (Advanced CMOS)
• 74ALS04 (Advanced Low-Power Schottky TTL)
• 74F04 (Very High Speed)
• 74C04 (CMOS, similar to the 4000-series)

Some manufacturers also add a prefix, such as the SN74HC04 and SN74LS04 by Texas Instruments.

Can’t find the 74×04 anywhere? Then try one of the following IC alternatives:

• 74×05 – Hex inverters (with open-collector outputs).
• 74×14 – Hex inverters (with Schmitt-trigger inputs).
• CD4049 – Hex inverting buffers/converter.
• CD4069 – Hex inverters/NOT-gates.
• CD40106 – Hex inverters (with Schmitt-trigger inputs).

If you can’t find the 74×04 IC in your local electronics store, don’t worry, you’ll most likely find it in one of the stores listed on this page of online stores where you’ll find components and tools for all your electronics projects.

Datasheet for the 74LS04 and 74HC04 chips

Download the PDF datasheet for your version of the 74×04 here:

• SN74HC04 (Texas Instruments)
• SN74LS04 (Texas Instruments)
• 74HC04 (Futurlec)
• 74LS04 (Futurlec)
• 74HC04 (Diodes Inc)