SN74HC21NE4

Inverter Gates Overview

The SN74HC21NE4 is a dual 4-input positive-AND gate manufactured by Texas Instruments in the HC logic family. It operates within a supply voltage range of 2 V to 6 V and supports an operating temperature range from -40°C to +85°C. The device features buffered inputs, balanced CMOS push-pull outputs, and standard high-impedance CMOS input characteristics. It provides significant power reduction compared to LSTTL logic ICs and supports fanout up to 10 LSTTL loads.

Inverter Gates Feature Summary

• Contains two independent 4-input AND gates performing Boolean function Y = A • B • C • D
• Balanced CMOS push-pull outputs capable of sinking and sourcing similar currents
• Standard CMOS inputs with high impedance and clamping diode structures

Inverter Gates Applications

• Combining power good signals
• Enabling digital signals
• Directly controlling motor controller reset pins

Inverter Gates Procurement Notes

Verify the ordering suffix 'E' indicates RoHS compliance and green material status. Confirm the package type is PDIP (N) with 14 pins. Ensure the operating temperature range matches the application requirements (-40°C to +85°C). Check for availability as the part is listed as active production.

Inverter Gates Selection Notes

Select this component when multiple independent 4-input AND logic functions are required in a single package. It is suitable for designs needing wide voltage operation between 2 V and 6 V. Consider its balanced output drive capability for driving light loads while managing potential ringing through proper routing.

Inverter Gates Part Context

This device belongs to the SNx4HC21 series of dual 4-input AND gates. It is part of the broader HC logic family, which offers CMOS performance with compatibility to TTL loads. The NE4 variant specifically denotes the PDIP package with environmental compliance features.

Inverter Gates Replacement Considerations

SN74HC21N: Standard PDIP version without explicit E suffix designation in some contexts.

Inverter Gates FAQ

How should unused inputs be handled?

Unused inputs must not be left floating. They should be terminated to either VCC or ground using pull-up or pull-down resistors to prevent undefined operational states.

What is the maximum capacitive load recommended?

The datasheet recommends ensuring the capacitive load at the output is less than or equal to 70 pF for optimal performance, though larger loads may be applied with caution.