Texas Instruments

SN74LS90DR

SN74LS90DR Description

The SN74LS90DR from Texas Instruments is a 4-bit decade counter designed for high-speed counting applications. Housed in a 14-SOIC surface-mount package, this IC operates within a 4.75V to 5.25V supply range and supports a 42 MHz count rate, making it suitable for precision timing and frequency division tasks. Its negative-edge triggering ensures reliable synchronization in digital circuits, while asynchronous reset allows immediate counter clearing. The device is ROHS3 compliant and rated for 0°C to 70°C operation, aligning with industrial and consumer electronics standards.

SN74LS90DR Features

• Decade Counter Logic: Counts in BCD (0-9) sequence, ideal for decimal-based systems.
• High-Speed Operation: 42 MHz count rate enables rapid pulse processing.
• Asynchronous Reset: Independent reset control for immediate counter initialization.
• Low Power Consumption: Part of the 74LS series, optimized for efficient power use.
• Surface-Mount Design: 14-SOIC package saves board space in compact designs.
• Wide Voltage Range: Operates reliably at 4.75V–5.25V, compatible with TTL logic levels.
• Robust Compliance: REACH unaffected, MSL 1 (unlimited shelf life).

SN74LS90DR Applications

• Frequency Dividers: Converts high-frequency clock signals into lower-frequency outputs.
• Digital Clocks/Timers: BCD counting suits 7-segment display drivers.
• Industrial Control Systems: Used in PLCs for event counting and sequencing.
• Consumer Electronics: Embedded in appliances for timing functions.
• Test Equipment: Provides precise counting in frequency meters and pulse generators.

Conclusion of SN74LS90DR

The SN74LS90DR combines high-speed performance, low power consumption, and ease of integration, making it a versatile choice for decade counting applications. Its asynchronous reset and BCD output distinguish it from generic binary counters, while the surface-mount package ensures compatibility with modern PCB designs. Whether for industrial automation, consumer devices, or instrumentation, this IC delivers reliable counting functionality with Texas Instruments' quality assurance.