SCEA135 june   2023 TXB0101 , TXB0102 , TXB0104 , TXB0104-Q1 , TXB0106 , TXB0106-Q1 , TXB0108 , TXB0302 , TXB0304 , TXS0101 , TXS0101-Q1 , TXS0102 , TXS0102-Q1 , TXS0104E , TXS0104E-Q1 , TXS0108E , TXS0108E-Q1

 

  1.   1
  2.   Abstract
  3.   Trademarks
  4. 1Introduction
  5. 2The One-shot's Designed Duration
    1. 2.1 Design Considerations
    2. 2.2 Recommended Parts
  6. 3Design Considerations for Slow Rise and Fall Times
    1. 3.1 Design Considerations
    2. 3.2 Recommended Parts
  7. 4Consider the Impact of External RC Components on Rise and Fall Times
    1. 4.1 Design Considerations
    2. 4.2 Recommended Parts
  8. 5Consider the Lumped Capacitance
    1. 5.1 Design Considerations
    2. 5.2 Recommended Parts
  9. 6Consider the Effects of Temperature on the Output Impedance
    1.     Design Considerations
  10. 7Summary
  11. 8References

Abstract

Auto Directional level shifter families are designed with weaker outputs than devices from other level shifting families, to be easily overdriven by the hosts. This makes Auto Direction devices a requirement for bidirectional interfaces such as I2C, MDIO, Quad-SPI, and so on.

The TXS and TXB Auto Directional level shifter families as shown in Voltage Translators and Level Shifters are designed with edge rate accelerators (commonly known as one-shots). The one-shots are designed for a set duration of pulse width for optimal signal integrity, impacted by RC components. Therefore, intentional and careful considerations should be made when used with additional external components as majority of one-shot concerns are due to improper use of the devices, false triggering of the one-shots and poor layout design.