7400 Series Guide: 74HC93/74LS93 (Divide-by-16 Counter)

The 74×93 (ex 74LS93) is a chip with a counter that counts from 0 to 15, then resets back to 0.

In this guide, you’ll learn the things you need to know about this chip in order to use divide-by-16 counters in your own projects.

What does the 74HC93 / 74LS93 do?

The 74×93 is a divide-by-16 counter. It is used for counting purposes in digital systems, where it can count from 0 to 15 in binary (4 bits). It’s also known as a “ripple” counter because the counting ripples from one flip-flop to the next in the sequence.

How To Use This Chip

The 74HC93 comes in a 14-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 74HC93 supports 2V to 6V, while the 74LS93 only supports 5V.

The maximum current you can pull out of one output pin of the 74LS93 is 0.8 mA when the pin is high (sourcing) or 16 mA when the pin is low (sinking). For 74HC chips, it’s usually 4 mA both sourcing and sinking.

This can differ between models, so check the datasheet of your model to verify.

The chip actually contains two counters, so to count up to 16, you need to connect the CLK1 input to the Q0 output. Then use CLK0 as the input for your counting pulses.

By using CLK0 as your clock input and connecting Q0 to CLK1, you’re setting up the IC to count to 16. The CLK0 input drives the divide-by-2 counter, and the connection of Q0 to CP1 enables the divide-by-8 counter. Together, these configure the IC to divide the input clock by 16, thereby counting from 0 to 15 before resetting to 0.

74×93 Pinout

The 74×93 has 14 pins and contains a 4-bit asynchronous binary counter with its pins laid out as shown in the pinout diagram below:

Pin Name	Pin #	Type	Description
CLK1	1	Input	Clock input for the divide-by-two section (active low).
–	2	NC	Not connected.
RST2	3	Input	Reset input for the counter, clears all outputs when high.
–	4	NC	Not connected.
VCC	5	Power	Positive power supply. Connect to +5V power.
–	6	NC	Not connected.
–	7	NC	Not connected.
Q2	8	Output	Second bit output in the counter sequence.
Q1	9	Output	First bit output in the counter sequence.
GND	10	Power	Connect to ground (GND).
Q3	11	Output	Third bit output in the counter sequence.
Q0	12	Output	Least significant bit output in the counter sequence.
–	13	NC	Not connected.
CLK0	14	Input	Clock input for the divide-by-eight section (active low).

Alternatives and Equivalents for 74HC93 / 74LS93

There are many versions of the 74×93 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:

• 74HC93 (High-speed CMOS)
• 74HCT93 (High-speed CMOS, TTL compatible)
• 74LS93 (High-speed TTL)
• 74LVC93 (Low Voltage TTL)
• 74AC93 (Advanced CMOS)
• 74ALS93 (Advanced Low-Power Schottky TTL)
• 74F93 (Very High Speed)
• 74C93 (CMOS, similar to the 4000-series)

Some manufacturers also add a prefix, such as the SN74HC93 and SN74LS93 by Texas Instruments.

Can’t find the 74×93 anywhere? Then try one of the following IC alternatives:

• CD4018 – Presettable divide-by-N counter
• CD4059 – Programmable divide-by-N counter
• CD4522 – Programmable BCD divide-by-N counter

If you can’t find the 74×93 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 74LS93 and 74HC93 chips

Download the PDF datasheet for your version of the 74×93 here:

• SN74LS93 (Texas Instruments)
• 74LS93 (Futurlec)