SCLS873B July   2021  – October 2022 SN74HCS244

PRODMIX  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
  4. 4 Revision History
  5. 5 Pin Configuration and Functions
  6. 6 Specifications
    1. 6.1 Absolute Maximum Ratings
    2. 6.2 ESD Ratings
    3. 6.3 Recommended Operating Conditions
    4. 6.4 Thermal Information
    5. 6.5 Electrical Characteristics
    6. 6.6 Switching Characteristics
    7. 6.7 Operating Characteristics
    8. 6.8 Typical Characteristics
  7. 7 Parameter Measurement Information
  8. 8 Detailed Description
    1. 8.1 Overview
    2. 8.2 Functional Block Diagram
    3. 8.3 Feature Description
      1. 8.3.1 Balanced CMOS 3-State Outputs
      2. 8.3.2 Balanced CMOS Push-Pull Outputs
      3. 8.3.3 Open-Drain CMOS Outputs
      4. 8.3.4 CMOS Schmitt-Trigger Inputs
      5. 8.3.5 TTL-Compatible CMOS Inputs
      6. 8.3.6 Standard CMOS Inputs
      7. 8.3.7 Clamp Diode Structure
      8. 8.3.8 Wettable Flanks
    4. 8.4 Device Functional Modes
  9. 9 Application and Implementation
    1. 9.1 Application Information
    2. 9.2 Typical Application
      1. 9.2.1 Design Requirements
        1. 9.2.1.1 Power Considerations
        2. 9.2.1.2 Input Considerations
        3. 9.2.1.3 Output Considerations
      2. 9.2.2 Detailed Design Procedure
      3. 9.2.3 Application Curves
  10. 10Power Supply Recommendations
  11. 11Layout
    1. 11.1 Layout Guidelines
    2. 11.2 Layout Example
  12. 12Device and Documentation Support
    1. 12.1 Documentation Support
      1. 12.1.1 Related Documentation
    2. 12.2 Receiving Notification of Documentation Updates
    3. 12.3 Support Resources
    4. 12.4 Trademarks
    5. 12.5 Electrostatic Discharge Caution
    6. 12.6 Glossary
  13. 13Mechanical, Packaging, and Orderable Information

Package Options

Mechanical Data (Package|Pins)
Thermal pad, mechanical data (Package|Pins)
Orderable Information

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.

The positive voltage supply must be capable of sourcing current equal to the total current to be sourced by all outputs of the SN74HCS244 plus the maximum static supply current, ICC, listed in Electrical Characteristics and any transient current required for switching. The logic device can only source as much current as is provided by the positive supply source. Be sure not to exceed the maximum total current through VCC listed in the Absolute Maximum Ratings.

The ground must be capable of sinking current equal to the total current to be sunk by all outputs of the SN74HCS244 plus the maximum supply current, ICC, listed in Electrical Characteristics, and any transient current required for switching. The logic device can only sink as much current as can be sunk into its ground connection. Be sure not to exceed the maximum total current through GND listed in the Absolute Maximum Ratings.

The SN74HCS244 can drive a load with a total capacitance less than or equal to 50 pF while still meeting all of the data sheet specifications. Larger capacitive loads can be applied; however, it is not recommended to exceed 50 pF.

The SN74HCS244 can drive a load with total resistance described by RL ≥ VO / IO, with the output voltage and current defined in the Electrical Characteristics table with VOH and VOL. When outputting in the high state, the output voltage in the equation is defined as the difference between the measured output voltage and the supply voltage at the VCC pin.

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.