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Low voltage not going to Zero Volts with TXB0108 Chip

Other Parts Discussed in Thread: TXB0108

HI All,

    I have a push-pull GPIO output which I am toggling to test the TXB0108 chip. Both VCCA and VCCB at set at 3.3V. Also OE = VCCA = 3.3V.  To diagnose my problem, I simply tested by toggling a GPIO pin. When I probe the level shifted output, I get the following as attached in this discussion.

It gives both the analog and digital view of the signals. I found that when the signal goes low, it reached a level of 1.11V and not zero. 

As a result, this is causing an issue with my boot up logic. Also when I bypass the TXB0108 chip, it works fine. I need to run the VCCA with 1.8V later and since my development board is 3.3V, I am verifying the chip function first.

Also note that this GPIO (output as shown) is connected to another CPU whose GPIO is configured as input floating.

Please comment why is the voltage not going to 0V?

Regards,

Vineet.