TXS0102: A1/B1 port IN/OUT issue

Roy Chou1

Part Number: TXS0102

Hi Team,

My customer is using TXS0102 as I2C level shifter. For A2/B2 port, the behavior is ok, but there is an issue on A1/B1 port.

We checked the A1 signal is ok, but when we connect to TXS0102A1 pin the signal low level will be clamped. And the B1 output will also be clamped. Can you let me know if there is anything we can check?

Roy

over 4 years ago

0 Dylan Hubbard over 4 years ago

TI__Mastermind 45985 points

Hey Roy,

Are there any external pull-ups connected to that channel? Refer to this app note that covers how added pull-ups impact the DC levels.

0 Roy Chou1 over 4 years ago in reply to Dylan Hubbard

TI__Genius 16190 points

Hi Dylan,

They have 4.7kohm on both of port, but I don't think it will boost so much VOL.

https://www.ti.com/lit/an/scea054a/scea054a.pdf

Roy

0 Clemens Ladisch over 4 years ago in reply to Roy Chou1

Guru 317280 points

The TXS is a passive switch; when the switch is on, it simply connects the A1 and B1 pins. The external device must be able to drive the current through all pull-up resistors (including the two internal 10 kΩ resistors). If that external device does not have enough drive strength, V_OL will increase.

Try removing the external pull-up resistors (the internal ones should be enough).

Logic

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TXS0102: A1/B1 port IN/OUT issue