SN74AS867DWR

Counter Dividers Overview

The SN74AS867DWR is a synchronous 8-bit up/down counter from the Texas Instruments AS logic family. It features internal-carry look-ahead circuitry for high-speed cascading and fully programmable preset capabilities allowing values between 0 and 255. The device operates on a positive-going clock edge with independent clocking to eliminate output counting spikes. It includes two count-enable inputs (ENP, ENT) and a ripple-carry output (RCO). The component is housed in a 24-pin SOIC (DW) package and supports a supply voltage range of 4.5 V to 5.5 V.

Counter Dividers Feature Summary

• Synchronous operation eliminates output counting spikes associated with asynchronous counters by clocking all flip-flops simultaneously.
• Internal carry look-ahead circuitry enables efficient n-bit cascading without additional external gating.
• Fully programmable parallel loading allows presetting the counter to any value between 0 and 255 synchronously.
• Independent clock circuit ensures mode changes via select inputs do not affect outputs until the next clock pulse.

Counter Dividers Applications

• High-speed synchronous counting applications requiring internal carry look-ahead
• Cascaded multi-bit counter systems utilizing ripple-carry outputs
• Digital systems requiring fully programmable presettable counters

Counter Dividers Procurement Notes

Verify the specific suffix 'DWR' corresponds to the SOIC-24 tape and reel packaging configuration. Confirm the operating temperature range matches the SN74AS series specification of 0°C to 70°C. Ensure the design accounts for the asynchronous clear feature unique to this variant compared to synchronous clear alternatives. Check for RoHS compliance status as indicated in the manufacturer's ordering information.

Counter Dividers Selection Notes

Select this component when synchronous counting with minimal propagation delay is required. The AS series offers higher speed than ALS variants but consumes more power. Use the DWR package for surface-mount assembly requirements. Consider the SN74ALS867A if lower power consumption is prioritized over maximum frequency performance.

Counter Dividers Part Context

This part belongs to the SN54/74AS series of synchronous 8-bit up/down counters. It shares functional similarities with the SN74ALS867A and SN74AS869, differing primarily in clear type and speed characteristics. The DW package option provides a standard small-outline integrated circuit form factor suitable for automated surface-mount placement processes.

Counter Dividers Replacement Considerations

SN74ALS867ADWR