7400 Series Guide: 74HC241/74LS241 (Octal 3-state buffer)

The 74×241 (ex 74LS241) is a cool little chip that has two 3-state buffers. One active low, one active high output enable.

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

What does the 74HC241 / 74LS241 do?

The 74×241 gives you two inverting 3-state buffers. One with an active low Output Enable (OE), and one active high Output Enable (OE).

This is very similar to the 74LS244, just that the second Output Enable pin is active high on this chip.

How To Use This Chip

The 74HC241 comes in a 20-pin package, and you need to connect it 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 74HC241 supports 2V to 6V, while the 74LS241 only supports 5V.

74HC chips can normally supply a maximum of 6 mA from an output pin. If you’re using the 74LS version, the maximum current you can pull out of one output pin is 15 mA when the pin is high (sourcing) or 24 mA when the pin is low (sinking).

But these values can differ between models, so check the datasheet of your model to verify.

Once you’ve connected it to power, you can use the unknown inside.

74×241 Pinout

The 74×241 has 20 pins and contains One active low, one active high output enable laid out as shown in the pinout diagram below:

Pin Name	Pin #	Type	Description
1OE	1	Input	Output Enable for bus line 1 (active low).
1A4	2	Input	Data input for first buffer line 4.
2Y1	3	Output	Data output from second buffer line 1.
1A3	4	Input	Data input for first buffer line 3.
2Y2	5	Output	Data output from second buffer line 2.
1A2	6	Input	Data input for first buffer line 2.
2Y3	7	Output	Data output from second buffer line 3.
1A1	8	Input	Data input for first buffer line 1.
2Y4	9	Output	Data output from second buffer line 4.
GND	10	Power	Connect to ground (GND).
2A1	11	Input	Data input for second buffer line 1.
1Y4	12	Output	Data output from first buffer line 4.
2A2	13	Input	Data input for second buffer line 2.
1Y3	14	Output	Data output from first buffer line 3.
2A3	15	Input	Data input for second buffer line 3.
1Y2	16	Output	Data output from first buffer line 2.
2A4	17	Input	Data input for second buffer line 4.
1Y1	18	Output	Data output from first buffer line 1.
2OE	19	Input	Output Enable for bus line 2 (active high).
VCC	20	Power	Positive power supply. Connect to +5V power.

Alternatives and Equivalents for 74HC241 / 74LS241

There are many versions of the 74×241 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:

• 74HC241 (High-speed CMOS)
• 74HCT241 (High-speed CMOS, TTL compatible)
• 74LS241 (High-speed TTL)
• 74LVC241 (Low Voltage TTL)
• 74AC241 (Advanced CMOS)
• 74ALS241 (Advanced Low-Power Schottky TTL)
• 74F241 (Very High Speed)
• 74C241 (CMOS, similar to the 4000-series)

Some manufacturers also add a prefix, such as the SN74HC241 and SN74LS241 by Texas Instruments.

Can’t find the 74×241 anywhere? Then try one of the following IC alternatives:

• 74×240 – Octal buffer/line driver with inverted outputs.
• 74×244 – Octal buffer/line driver with non-inverted outputs.
• 74×245 – Octal bus transceiver with non-inverted outputs.
• 74×541 – Octal buffer/line driver with 3-state outputs.
• 74×640 – Octal bus transceiver.
• 74×645 – Octal bus transceiver with inverted outputs.
• CD4503 – Hex non-inverting 3-state buffer.

If you can’t find the 74×241 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 74LS241 and 74HC241 chips

Download the PDF datasheet for your version of the 74×241 here:

• SN74HC241 (Texas Instruments)
• SN74LS241 (Texas Instruments)
• 74LS241 (Futurlec)
• 74HC241 (Nexperia)