SN74HC4020D

Overview

The SN74HC4020D is a 14-bit asynchronous binary counter in a 16-pin SOIC package. It operates on the negative-going edge of the clock pulse and features an overriding asynchronous master reset input that clears all outputs to low when high. The device supports a supply voltage range of 2 V to 6 V, with a recommended operating temperature of -40°C to +85°C. It provides up to 10 LSTTL load drive capability and includes input clamp diodes for interfacing.

Feature Summary

• 14-stage binary ripple-carry counting functionality advancing on negative clock edges
• Asynchronous master reset input independent of clock state
• Wide supply voltage operation from 2 V to 6 V
• Input clamp diodes enable direct interfacing with voltages exceeding VCC

Applications

• Frequency dividing circuits
• Time delay circuits
• Control counters

Procurement Notes

Verify current production status as the SN74HC4020D is listed as obsolete in official documentation. Confirm availability of active alternatives such as the SN74HC4020DR or SN74HC4020PWR before finalizing procurement plans. Ensure compliance with RoHS standards and check moisture sensitivity levels for surface mount assembly requirements.

Selection Notes

Select this component for applications requiring 14-bit binary counting within standard CMOS logic families. Consider the SN74HCT4020 if TTL-level inputs are necessary. Evaluate thermal resistance and package constraints, noting the SOIC body size dimensions. Verify power supply bypassing recommendations to prevent disturbances during operation.

Part Context

This part belongs to the Texas Instruments SNx4HC4020 family of 14-bit asynchronous binary counters. The HC series denotes standard CMOS technology compatible with various digital logic systems. The 'D' suffix specifically identifies the 16-lead Small Outline Integrated Circuit (SOIC) package variant designed for surface mount applications.

Replacement Considerations

SN74HC4020DR

FAQ

How does the asynchronous reset function operate?

The master reset input overrides the clock input. When the clear input goes high, all counter stages are reset to zero and outputs go low, regardless of the clock state.

What is the trigger mechanism for counting?

The counter advances to the next stage on the negative-going edge (HIGH-to-LOW transition) of the clock pulse.