9 Application and Implementation

Note

Information in the following applications sections is not part of the TI component specification,

and TI does not warrant its accuracy or completeness. TI’s customers are responsible for

determining suitability of components for their purposes, as well as validating and testing their design

implementation to confirm system functionality.

9.1 Application Information

In this application, one open-drain inverter is used as shown in Figure 9-1. The other five channels can be used

for other applications in the system, or the inputs can be grounded and the channels left unused.

This device is used to directly control an LED. The LED is on when the input is high, and off when the input is

low.

9.2 Typical Application

VCC

R1

VCC

Input

Figure 9-1. Typical application schematic

9.2.1 Design Requirements

9.2.1.1 Power Considerations

Ensure the desired supply voltage is within the range specified in the Recommended Operating Conditions. The

supply voltage sets the device's electrical characteristics as described in the Electrical Characteristics - 74.

The ground must be capable of sinking current equal to the total current to be sunk by all outputs of the

SN74HC05 plus the maximum supply current, ICC, listed in Electrical Characteristics - 74. The logic device can

only sink as much current as is provided by the external pull-up resistor or other supply source. Be sure not to

exceed the maximum total current through GND listed in the Absolute Maximum Ratings.

Total power consumption can be calculated using the information provided in CMOS Power Consumption and

Cpd Calculation.

Thermal increase can be calculated using the information provided in Thermal Characteristics of Standard Linear

and Logic (SLL) Packages and Devices.

CAUTION

The maximum junction temperature, TJ(max) listed in the Absolute Maximum Ratings, is an

additional limitation to prevent damage to the device. Do not violate any values listed in the Absolute

Maximum Ratings. These limits are provided to prevent damage to the device.

9.2.1.2 Input Considerations

Unused inputs must be terminated to either VCC or ground. These can be directly terminated if the input is

completely unused, or they can be connected with a pull-up or pull-down resistor if the input is to be used

sometimes, but not always. A pull-up resistor is used for a default state of HIGH, and a pull-down resistor is

used for a default state of LOW. The resistor size is limited by drive current of the controller, leakage current into

www.ti.com

SN74HC05, SN54HC05

SCLS080F – MARCH 1984 – REVISED APRIL 2021

Copyright © 2021 Texas Instruments Incorporated

Submit Document Feedback

11

Product Folder Links: SN74HC05 SN54HC05