SN74ALS191AN

Counter Dividers Overview

The SN74ALS191AN is a synchronous 4-bit reversible up/down binary counter manufactured by Texas Instruments. It operates within a supply voltage range of 4.5 V to 5.5 V and supports clock frequencies up to 30 MHz. The device features asynchronous preset capability via the LOAD control input, allowing outputs to be set independently of the clock signal. It includes look-ahead circuitry for cascading applications and buffered inputs (CLK, D/U, LOAD) to reduce driver loading. The component is housed in a standard plastic 16-pin DIP package and is rated for an operating temperature range of 0°C to 70°C.

Counter Dividers Feature Summary

• Synchronous counting operation eliminates output spikes associated with asynchronous ripple-clock counters.
• Asynchronously programmable preset allows direct data entry to outputs without clock dependency.
• Look-ahead circuitry enhances speed when cascading multiple counters.
• Buffered control inputs significantly reduce drive requirements for long parallel words.

Counter Dividers Applications

• Modulo-N frequency division circuits
• High-speed digital counting systems
• Cascaded multi-stage binary counters

Counter Dividers Procurement Notes

Verify that the specific ordering suffix 'AN' corresponds to the Plastic DIP (N) package variant. Confirm the manufacturer's current production status, as legacy logic families may have discontinued variants or require checking for active manufacturing availability through official TI channels before finalizing procurement plans.

Counter Dividers Selection Notes

Select this component for designs requiring fully synchronous 4-bit reversible counting with minimal propagation delay variations. Ensure the application environment remains within the specified 0°C to 70°C commercial temperature range. Verify that the system power supply strictly adheres to the 4.5 V to 5.5 V limits to maintain electrical characteristics.

Counter Dividers Part Context

This part belongs to the Texas Instruments 74ALS logic family, which utilizes Advanced Low-Power Schottky technology. The 'SN74' prefix indicates it is a commercial-grade device, distinct from the military-grade SN54 series. It serves as a core timing element in digital electronics, providing reliable binary counting functions compatible with standard TTL interfaces.

Counter Dividers Replacement Considerations

Public confirmed substitute: SN74ALS191ADR.