The 54AC191DMQB is a synchronous 4-Bit Up/Down Binary Counter from the 54AC family of advanced CMOS logic devices manufactured by National Semiconductor (now Texas Instruments). This device features a versatile design for implementing counting functions in a variety of digital systems.

Applications:

• Frequency Dividers: Used to divide a clock frequency by a specific factor.
• Address Generation: Employed in memory addressing schemes.
• Timing Circuits: Incorporated into timing circuits requiring precise counting intervals.
• Digital Clocks: Used as the core counting element in digital clock designs.
• Event Counters: Counts the occurrence of specific events in a system.

Features:

• Synchronous Counting: All flip-flops are clocked simultaneously, ensuring accurate and predictable counting.
• Up/Down Counting: Capable of counting both upwards and downwards, providing flexibility in counting applications.
• 4-Bit Binary Counter: Counts from 0 to 15 (binary 0000 to 1111) and vice versa.
• Asynchronous Master Reset: Allows for immediate reset of the counter, regardless of the clock signal.
• Carry Output: Provides a carry output for cascading multiple counters to create larger counting ranges.
• Clock Enable Input: Enables or disables the counting function, allowing for controlled counting operations.
• Mode Control Input: Determines the counting direction (up or down).
• Military Temperature Range: Operates reliably over a wide temperature range, suitable for military and aerospace applications.

Benefits:

• High Speed Operation: The advanced CMOS technology enables fast counting speeds.
• Low Power Consumption: CMOS technology ensures low power consumption, making it suitable for battery-powered applications.
• Versatile Functionality: The up/down counting capability and other control inputs provide flexibility in various counting applications.
• Reliable Operation: The military temperature range ensures reliable operation in harsh environments.
• Cascadability: The carry output allows for easy cascading of multiple counters to create larger counting ranges.

Additional Details:

The 54AC191DMQB operates with a supply voltage of 4.5V to 5.5V. It is available in a ceramic Dual In-line Package (DIP). The device is designed to meet the stringent requirements of military and aerospace applications, offering high reliability and performance. The synchronous counting mechanism ensures that all flip-flops change state simultaneously, preventing glitches and ensuring accurate counting. The asynchronous master reset provides a convenient way to reset the counter to its initial state. The carry output allows for cascading multiple counters to create larger counting ranges, making it suitable for applications requiring high counting resolution.