SCES885 April   2017 SN74LVC1G80-Q1

PRODUCTION DATA.  

  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  Timing Requirements: TA = -40°C to +85°C
    7. 6.7  Timing Requirements: TA = -40°C to +125°C
    8. 6.8  Switching Characteristics: TA = -40°C to +85°C, CL = 15 pF
    9. 6.9  Switching Characteristics: TA = -40°C to +85°C, CL = 30 pF or 50 pF
    10. 6.10 Switching Characteristics: TA = -40°C to +125°C, CL = 30 pF or 50 pF
    11. 6.11 Operating Characteristics
    12. 6.12 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 High-Drive CMOS Push-Pull Outputs
      2. 8.3.2 Standard CMOS Inputs
      3. 8.3.3 Clamp Diodes
      4. 8.3.4 Partial Power Down (Ioff)
      5. 8.3.5 Over-Voltage Tolerant Inputs
    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
      2. 9.2.2 Detailed Design Procedure
      3. 9.2.3 Application Curve
  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 Community 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 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. Customers should validate and test their design implementation to confirm system functionality.

9.1 Application Information

A useful application for the SN74LVC1G80-Q1 is using it as a frequency divider. By feeding back the output (Q) to the input (D), the output will toggle on every rising edge of the clock waveform. The output goes HIGH once every two clock cycles so essentially the frequency of the clock signal is divided by a factor of two. The SN74LVC1G80-Q1 does not have preset or clear functions so the initial state of the output is unknown. This application implements the use of a microcontroller GPIO pin to initially set the input HIGH, so the output LOW. Initialization is not needed, but should be kept in mind. Post initialization, the GPIO pin is set to a high impedance mode. Depending on the microcontroller, the GPIO pin could be set to an input and used to monitor the clock division.

9.2 Typical Application

SN74LVC1G80-Q1 fbd-01-sces221.gif Figure 7. Clock Frequency Division

9.2.1 Design Requirements

For this application, a resistor needs to be placed on the feedback line in order for the initialization voltage from the microcontroller to overpower the signal coming from the output (Q). Without it the state at the input would be challenged by the GPIO from the microcontroller and from the output of the SN74LVC1G80-Q1.

The SN74LVC1G80-Q1 device uses CMOS technology and has balanced output drive. Take care to avoid bus contention because it can drive currents that would exceed maximum limits.

9.2.2 Detailed Design Procedure

  1. Recommended input conditions:
  2. Recommended output conditions:
  3. Feedback resistor:
    • A 10-kΩ resistor is chosen here to bias the input so the microcontroller GPIO output can initialize the input and output. The resistor value is important because a resistance too high, say at 1 MΩ, would cause too much of a voltage drop, causing the output to no longer be able to drive the input. On the other hand, a resistor too low, such as a 1 Ω, would not bias enough and might cause current to flow into the microcontroller, possibly damaging the device.

9.2.3 Application Curve

SN74LVC1G80-Q1 schem-01-sces221.gif Figure 8. Frequency Division