SCAS988 March   2024 SN74LV8T244-Q1

ADVANCE INFORMATION  

  1.   1
  2. 1 Features
  3. 2 Applications
  4. 3 Description
  5. 4 Pin Configuration and Functions
  6. 5 Specifications
    1. 5.1 Absolute Maximum Ratings
    2. 5.2 ESD Ratings
    3. 5.3 Recommended Operating Conditions
    4. 5.4 Thermal Information
    5. 5.5 Electrical Characteristics
    6. 5.6 Switching Characteristics
    7. 5.7 Typical Characteristics
  7. 6 Parameter Measurement Information
  8. 7 Detailed Description
    1. 7.1 Overview
    2. 7.2 Functional Block Diagram
  9. 8 Feature Description
    1. 8.1 Balanced CMOS 3-State Outputs
    2. 8.2 LVxT Enhanced Input Voltage
    3. 8.3 Clamp Diode Structure
  10. 9 Device Functional Modes
  11. 10Application and Implementation
    1. 10.1 Application Information
    2. 10.2 Typical Application
      1. 10.2.1 Design Requirements
        1. 10.2.1.1 Power Considerations
        2. 10.2.1.2 Input Considerations
        3. 10.2.1.3 Output Considerations
      2. 10.2.2 Detailed Design Procedure
      3. 10.2.3 Application Curves
    3. 10.3 Power Supply Recommendations
    4. 10.4 Layout
      1. 10.4.1 Layout Guidelines
      2. 10.4.2 Layout Example
  12. 11Device and Documentation Support
    1. 11.1 Documentation Support
      1. 11.1.1 Related Documentation
    2. 11.2 Receiving Notification of Documentation Updates
    3. 11.3 Support Resources
    4. 11.4 Trademarks
    5. 11.5 Electrostatic Discharge Caution
    6. 11.6 Glossary
  13. 12Revision History
  14. 13Mechanical, Packaging, and Orderable Information
    1. 13.1 Tape and Reel Information
    2. 13.2 Mechanical Data

Package Options

Refer to the PDF data sheet for device specific package drawings

Mechanical Data (Package|Pins)
  • PW|20
Thermal pad, mechanical data (Package|Pins)
Orderable Information

8.2 LVxT Enhanced Input Voltage

The SN74LV8T244-Q1 belongs to TI's LVxT family of logic devices with integrated voltage level translation. This family of devices was designed with reduced input voltage thresholds to support up-translation, and inputs tolerant of signals with up to 5.5V levels to support down-translation. For proper functionality, input signals must remain at or above the specified VIH(MIN) level for a HIGH input state, and at or below the specified VIL(MAX) for a LOW input state. Figure 8-1 shows the typical VIH and VIL levels for the LVxT family of devices, as well as the voltage levels for standard CMOS devices for comparison.

The 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).

Input signals must transition between valid logic states quickly, as defined by the input transition rate in the Recommended Operating Conditions table. Failing to meet this specification will result in excessive power consumption and could cause oscillations. More details can be found in the Implications of Slow or Floating CMOS Inputs application report.

Do not leave inputs floating at any time during operation. Unused inputs must be terminated at a valid high or low voltage level. If a system will not be actively driving an input at all times, then a pull-up or pull-down resistor can be added to provide a valid input voltage during these times. The resistor value will depend on multiple factors; however, a 10kΩ resistor is recommended and will typically meet all requirements.

GUID-CA950F6B-2B3F-4FDE-87C0-F51047C4B97A-low.gifFigure 8-1 LVxT Input Voltage Levels