74LS22 Dual 4-Input positive NAND Gate IC

74LS22 designed as a high-speed Dual 4-Input Positive NAND gate IC fabricated in low power schotkey technology. These devices come with four independent 4-input Positive-NAND gates. They perform the Boolean functions Y = A • B.C.D   or Y = A + B+C+D in positive logic. The 74LS22 designed as an advanced high speed CMOS 4 Input NAND circuit fabricated with silicon gate CMOS technology. It achieves a high−speed operation similar to equivalent Bipolar Schottky TTL. Thereby maintaining the CMOS low power dissipation almost like LS-TTL gates. In this IC, the open collector outputs require pull−up resistors to function  correctly. They may be connected to other open collector outputs to implement active−low wired−OR or active−high wired−AND functions. Open collector devices often used to generate higher VOH levels.

 74LS22 manufactured in 14−pin plastic PDIP wide body surface mount packages. The 74LS22 designed for operation over the full military temperature range of 0°C to 70°C. All inputs shielded from damage due to static discharge by internal diode clamps to VCC and ground. The 74LS logic family is functionally as well as pin-out compatible with the standard 74HC logic family.

NAND gate defined as a digital logic gate most commonly used in DLD applications. It also sometimes referred to as a universal logic gate, as it  used to implement any logic gate or expression in existence. Incase, if any one of the inputs to the NAND gate switch to high, the output of the gate will also a logical low. On the other hand, a NAND gate yields a logical high only when all of its inputs set to LOW.