TXS0108E-Q1: Ringing issues for 5 Mhz Communication Signals

Part Number: TXS0108E-Q1
Other Parts Discussed in Thread: TXS0108E

Tool/software:

Hello, I am using the TXS0108E as a level shifter from 3.3V to 5V for my 5 MHz SPI. Unfortunately, I am experiencing unwanted ringing on the edges. To address this, I added a resistor R5 (see schematic) as a damping element, but the TXS0108E distorts the signal as soon as I use a higher resistor value. Why is this happening, and how can I mitigate this ringing?

Scope picture R5 = 0 Ohms

Scope picture R5 = 33 Ohms

Scope picture R5 = 75 Ohms

  • Hi Oliver,

    External pullups/ pulldowns can be removed as the device has internal pullups already. The ringing is most likely due to excessive cap. load at the outputs, similar to section 7.3.3 and 8.4.1 entails. 

    Please use shorter cables/ traces and test again. Tip & Barrel probes may also be used during waveform captures to help in reducing the ground loop/ inductance.

    Regards,

    Jack