7400 Series Guide: 74HC7032 (OR gates)

The 74HC7032 is a cool little chip that has four OR gates with Schmitt-triggers. Schmitt-trigger gates are great because they can handle more noise. But the really cool thing is that they make it easy to build oscillators for all sorts of fun circuits. They also work as replacements for normal OR gates.

In this guide, you will learn everything you need to know about this chip and how you can use its OR gates in your own projects.

What does the 74HC7032 do?

The 74HC7032 gives you four Schmitt-trigger OR gates that can be used individually. An OR gate is a logic gate that outputs 1 (HIGH) if one of it inputs are 1 (HIGH). In the truth table below, you can see what the output will be for any given input:

What is a Schmitt Trigger?

Gate inputs that are Schmitt-triggered are inputs where the threshold for going from 0 to 1 is different from the threshold for going from 1 to 0.

If you power this chip with three AA batteries (4.5V), you need the voltage on the input to go above 2V before it’s accepted as a 1 (HIGH). Once it’s HIGH, the voltage needs to drop below 0.9V for the input to be accepted as a 0 (LOW). (You can find these values from the datasheet).

How To Use This Chip

The 74HC7032 comes in a 14-pin package, and you need to connect it to a power supply of 2V to 6V before you can use it. Once connected, all of the four Schmitt-trigger OR gates are at your disposal. Each gate output can sink or source 4 mA when powered with 5V.

74HC7032 Pinout

Pin #	Type	Description
1	Input	Input to the first OR gate.
2	Input	Input to the first OR gate.
3	Output	Output from the first OR gate.
4	Input	Input to the second OR gate.
5	Input	Input to the second OR gate.
6	Output	Output from the second OR gate.
7	Power	Connect to ground (GND).
8	Output	Output from the third OR gate.
9	Input	Input to the third OR gate.
10	Input	Input to the third OR gate.
11	Output	Output from the fourth OR gate.
12	Input	Input to the fourth OR gate.
13	Input	Input to the fourth OR gate.
14	Power	Positive power supply (VCC). Connect to +5V power.

74HC7032 Circuit Example

Here’s a simple project you can build with the OR gates in the this chip:

The pull-down resistors pull both inputs to the OR gate LOW when the buttons are not pushed. Push any of the buttons, and you’ll make the input pin HIGH. A HIGH on any of the inputs will turn on the output and thereby turn on the Light-Emitting Diode (LED).

So the LED will turn on if you push any of the buttons.

You’ll need the following parts to build this circuit:

• 1 x 74HC7032
• 1 x LED (L1)
• 2 x 10 kΩ resistor (R1-R2)
• 1 x 1 kΩ resistor (R3)
• 2 x pushbutton (S1-S2)

Alternatives for the 74HC7032

Can’t find the 74HC7032 anywhere? Then try one of the following IC alternatives:

• 74×32 – Quad 2-input Schmitt-trigger OR gates
• CD4071 – Quad 2-input Schmitt-trigger OR gates.

If you can’t find the 74HC7032 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 74HC7032 chip

Download the PDF datasheet for your version of the 74×7032 here:

• SN74HC7032 (Texas Instruments)