The SN74LS90D is a versatile, high-performance device designed by Texas Instruments, which serves as a 4-bit binary counter. This integrated circuit (IC) is part of the 74LS logic family, known for its low power Schottky technology. It is widely used in digital systems for counting purposes and is suitable for various applications such as frequency division, time measurement, and sequential logic operations.
The SN74LS90D features a fully synchronous internal design, enabling it to respond quickly and reliably to clock inputs. It has a clear function that resets the counter to its zero state when a high level is applied, ensuring that the count starts from a clean slate whenever required. This device can count up to 9 (1001 in binary) and then recycle to zero, continuing the count cycle.
With its D-type flip-flop configuration, the SN74LS90D provides a direct clear input and individual jam inputs to each flip-flop. This allows for easy and direct setting or resetting of the counter bits. Additionally, the counter advances on the negative-going edge of the clock signal, which helps in reducing the possibility of clocking errors due to the transition times of the clock signal.
The device comes in a 14-pin SOIC (Small Outline Integrated Circuit) package, designated by the 'D' in its product name, making it suitable for surface-mount technology (SMT) applications. It operates over a wide voltage range and features a typical power dissipation of 45 mW, which is relatively low for a device of its capabilities. This makes the SN74LS90D an energy-efficient choice for battery-powered and portable devices.
Texas Instruments ensures that the SN74LS90D meets strict quality and reliability standards, providing robust performance for both commercial and industrial applications. With its combination of functionality, speed, and power efficiency, the SN74LS90D is an excellent choice for designers looking to implement a reliable binary counting solution in their digital systems.