8 Detailed Description

8.1 Overview

This device contains four independent 2-input NAND Gates with Schmitt-trigger inputs. Each gate performs the

Boolean function Y = A ● B in positive logic.

8.2 Functional Block Diagram

One of Four Channels

xA

xB

xY

8.3 Feature Description

8.3.1 Balanced CMOS Push-Pull Outputs

A balanced output allows the device to sink and source similar currents. The drive capability of this device

may create fast edges into light loads so routing and load conditions should be considered to prevent ringing.

Additionally, the outputs of this device are capable of driving larger currents than the device can sustain without

being damaged. It is important for the output power of the device to be limited to avoid damage due to

over-current. The electrical and thermal limits defined in the Absolute Maximum Ratings must be followed at all

times.

8.3.2 CMOS Schmitt-Trigger Inputs

Standard CMOS inputs are high impedance and are typically modeled as a resistor in parallel with the input

capacitance given in the Electrical Characteristics. The worst case resistance is calculated with the maximum

input voltage, given in the Absolute Maximum Ratings, and the maximum input leakage current, given in the

Electrical Characteristics, using ohm's law (R = V ÷ I).

which makes this device extremely tolerant to slow or noisy inputs. While the inputs can be driven much

slower than standard CMOS inputs, it is still recommended to properly terminate unused inputs. Driving the

inputs slowly will also increase dynamic current consumption of the device. For additional information regarding

Schmitt-trigger inputs, please see Understanding Schmitt Triggers.

8.3.3 Clamp Diode Structure

The inputs and outputs to this device have both positive and negative clamping diodes as depicted in Figure 8-1.

CAUTION

Voltages beyond the values specified in the Absolute Maximum Ratings table can cause damage to

the device. The input negative-voltage and output voltage ratings may be exceeded if the input and

output clamp-current ratings are observed.

www.ti.com

SN74HCS00

SCLS775C – DECEMBER 2019 – REVISED DECEMBER 2021

Copyright © 2021 Texas Instruments Incorporated

Submit Document Feedback

9

Product Folder Links: SN74HCS00