7400 Series Guide: 74HC07/74LS07 (Buffers with Open Collector)

The 74×07 (ex 74HC07) is an integrated circuit that has six buffers. Each buffer comes with an open collector output, which means you can easily connect it to chips that use different logic levels. However, it also means you can’t use the outputs as standard HIGH/LOW outputs.

In this guide, you will learn everything you need to know about buffers and open collector outputs so that you’re ready to use them in your own projects.

What does the 74HC07 / 74LS07 do?

The 74×07 gives you six buffers. A buffer gives the same logical output as the input. A 1 on the input gives a 1 on the output. And a 0 in gives a 0 out.

Buffers are often used as drivers. For example, if you have a chip with an output pin that can only provide 0.5 mA, and you need to control something that needs 10 mA, a buffer can help. It doesn’t change the logical values (1 or 0) but can provide more current.

Also, since this chip has open collector outputs, you can easily connect it to chips that use different logical levels.

How To Use This Chip

The 74HC07 comes in a 14-pin package. You need to connect it to power before using any of the buffers inside. While most 7400 ICs run on 5V, the 74HC07 works between 2V to 6V. On the other hand, the 74LS07 operates only at 5V.

Once you’ve connected it to a voltage supply, you can choose any (or all) of the six open-collector buffers inside and connect it to your logic.

74×07 Pinout

The 74×07 has 14 pins and contains six open-collector buffers. You can see how they are laid out in the pinout diagram below:

Pin Name	Pin #	Type	Description
1A	1	Input	Input to the first buffer.
1Y	2	Output	Open-collector output from the first buffer.
2A	3	Input	Input to the second buffer.
2Y	4	Output	Open-collector output from the second buffer.
3A	5	Input	Input to the third buffer.
3Y	6	Output	Open-collector output from the third buffer.
GND	7	Power	Connect to ground (GND).
4Y	8	Output	Open-collector output from the fourth buffer.
4A	9	Input	Input to the fourth buffer.
5Y	10	Output	Open-collector output from the fifth buffer.
5A	11	Input	Input to the fifth buffer.
6Y	12	Output	Open-collector output from the sixth buffer.
6A	13	Input	Input to the sixth buffer.
VCC	14	Power	Positive power supply (VCC). Connect to +5V power.

Alternatives and Equivalents for 74HC07 / 74LS07

There are many versions of the 74×07 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:

• 74HC07 (High-speed CMOS)
• 74HCT07 (High-speed CMOS, TTL compatible)
• 74LS07 (High-speed TTL)
• 74LVC07 (Low Voltage TTL)
• 74AC07 (Advanced CMOS)
• 74ALS07 (Advanced Low-Power Schottky TTL)
• 74F07 (Very High Speed)
• 74C07 (CMOS, similar to the 4000-series)

Some manufacturers also add a prefix, such as the SN74HC07 and SN74LS07 by Texas Instruments.

Can’t find the 74×07 anywhere? Then try one of the following IC alternatives:

• 74×34 – Hex buffer gate
• 74×35 – Hex buffer gate
• 74×7014 – Hex buffers (with Schmitt-trigger inputs).
• CD4049 – Hex Inverting Buffer and Converter
• CD4050 – Hex Buffer and Converter

If you can’t find the 74×07 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 74LS07 and 74HC07 chips

• SN74LS07 (Texas Instruments)
• 74HC07 (HGSemi)