The HD74LS191P is a synchronous 4-bit up/down binary counter manufactured by Renesas Electronics America. It is a member of the 74LS series of integrated circuits, known for their low-power Schottky TTL technology. This counter features a versatile design that allows it to count both up and down, making it suitable for a wide range of digital applications.

Applications:

• Frequency dividers
• Digital clocks
• Event counters
• Address counters for memory systems
• Industrial control systems

Features:

• Synchronous counting operation
• Up/down counting capability controlled by a single input
• Carry and borrow outputs for cascading counters
• Presetting capability for starting at a specific count
• TTL compatible inputs and outputs

Benefits:

• Versatile counting functionality in a single IC
• Easy cascading for higher-order counting
• Simple control for up/down counting direction
• Reliable operation due to TTL technology
• Reduces component count and board space

Technical Specifications:

The HD74LS191P operates from a 5V power supply and features a maximum clock frequency typically around 25 MHz. It has parallel load inputs for presetting the counter to a desired value. The up/down control input determines the counting direction. The carry and borrow outputs can be used to cascade multiple counters to create larger counting ranges. The device is packaged in a 16-pin DIP package.

The synchronous operation means that all flip-flops are clocked simultaneously, ensuring that the outputs change state at the same time, avoiding glitches and timing issues common in asynchronous counters. This makes the HD74LS191P a reliable choice for applications requiring precise counting.