SN74LS390DR

Counter Dividers Overview

The SN74LS390DR is a dual 4-bit decade and binary counter integrated circuit manufactured by Texas Instruments. It belongs to the 74LS logic series and operates within a supply voltage range of 4.75 V to 5.25 V. The device features asynchronous reset functionality and negative-edge triggering for both its decade and binary counting sections. Designed for through-hole or surface-mount applications depending on the package variant, it supports a maximum counting rate of 35 MHz. The component functions reliably across an operating temperature range from 0°C to +70°C.

Counter Dividers Feature Summary

• Dual independent 4-bit decade and binary counters
• Asynchronous reset capability with high priority
• Negative-edge triggered clock inputs
• Compatible with standard 74LS logic families

Counter Dividers Applications

• Digital frequency division circuits
• Timekeeping and clock generation systems
• Pulse counting and measurement devices
• Sequential logic control modules

Counter Dividers Procurement Notes

Verify the specific suffix against official Texas Instruments documentation to confirm package type and environmental compliance. Ensure the ordering part number matches the required pin configuration and RoHS status. Cross-reference datasheet revisions to validate electrical characteristics before integration into final designs.

Counter Dividers Selection Notes

Select this component when dual independent counting channels are required in a single package. The LS series offers speed suitable for moderate-frequency applications up to 35 MHz. Consider the DR package variant for surface-mount assembly requirements while maintaining compatibility with standard DIP pinouts.

Counter Dividers Part Context

This device is part of the SN54/74LS390 family, which includes variants like SN74LS390N and SN74LS393. It serves as a fundamental building block for digital systems requiring decade or binary counting operations. The SN74LS390DR specifically denotes the SOIC surface-mount package version of this dual counter IC.

Counter Dividers Replacement Considerations

SN74LS390N (PDIP package)

Counter Dividers FAQ

What is the difference between the decade and binary modes?

The first section operates as a divide-by-two binary counter, while the second section functions as a modulo-10 decade counter. They can be cascaded or used independently.

How is the reset function implemented?

The reset is asynchronous and active low. It overrides all other inputs and immediately clears the outputs to zero regardless of the clock state.