SN 74LS01 7401

SN 74LS01 7401
400 Series Guide: 74HC01/74LS01 (open-collector NAND gates) The 74×01 (ex 74LS01) is a basic logic chip with four open-collector NAND gates. When you’ve got an open collector output, it means you can easily connect it with other chips that use different voltage levels. But, it also means you can’t just replace it with a standard NAND gate chip. In this how-to guide, you’ll learn all about this chip and how to use NAND gates in your own projects. Chip package and pinout for the 74HC01/74LS01 74HC01 chip and pinout What does the 74HC01 / 74LS01 do? The 74×01 provides you with four independent open-collector NAND gates. A NAND gate is a type of logic gate that only outputs 0 (LOW) when all of its inputs are 1 (HIGH). The truth table below illustrates the possible outputs for any particular input: NAND gate truth table Truth table for the NAND gate How To Use This Chip The 74HC01 comes in a 14-pin package, and you need to connect it to power before you can use it. Most 7400 ICs can handle a supply voltage of 5V. If you want to use a different voltage, keep in mind that the HC version of the chip (74HC01) supports 2V to 6V, while the 74LS01 only supports 5V. 7400 series IC connected to 5V on a breadboard Once the chip has power, you can use any of the four open-collector NAND gates inside. Note that the outputs are open collector outputs, which means you can’t use them as normal HIGH/LOW outputs. 74×01 Pinout The 74×01 has 14 pins and contains four open-collector NAND gates laid out as shown in the pinout diagram below: Pinout for the 74HC01/74LS01 chip Pin # Type Description 1 Output Open-collector output from the first NAND gate. 2 Input Input to the first NAND gate. 3 Input Input to the first NAND gate. 4 Output Open-collector output from the second NAND gate. 5 Input Input to the second NAND gate. 6 Input Input to the second NAND gate. 7 Power Connect to ground (GND). 8 Input Input to the third NAND gate. 9 Input Input to the third NAND gate. 10 Output Open-collector output from the third NAND gate. 11 Input Input to the fourth NAND gate. 12 Input Input to the fourth NAND gate. 13 Output Open-collector output from the fourth NAND gate. 14 Power Positive power supply (VCC). Connect to +5V power.