VOL when multiple NTSX2102s are connected on the same I2C bus

[ikeryo]

In the case of one NTSX2102 on the I2C bus, VOL is about 200mV.

In the case of two, VOL increases to about 400mV. 

Is this normal behavior? I am having a problem that some devices on the I2C bus cannot be accessed.

Is it not recommended to connect multiple NTSX2102s on the same bus?

[JozefKozon]

Dear Ryo,

please find my answers bellow your questions in the description.

DESCRIPTION

In the case of one NTSX2102 on the I2C bus, VOL is about 200mV.

Maximum value of Vol is 400mV so anything between 0V to 400mV is correct for Vol. Please see the picture bellow.

In the case of two, VOL increases to about 400mV. 

The 400mV is a boundary value. In some cases might be ok in other the value might easily increase and cross the 400mV. The I/O pins are open drain. To be on safe side, try to increase values of the pull-up resistors. It should help and lower the Vol.

Is this normal behavior? I am having a problem that some devices on the I2C bus cannot be accessed.

The NTSX2102 is designed for one system controller on each side. Please see picture bellow for typical application. If you connect more devices on one or both sides it can do some mess up.

Is it not recommended to connect multiple NTSX2102s on the same bus?

It is recommended to connect only one device on each side. Please see the picture above. If you connect more devices on one or both sides it could exceed maximum output load. Please see bellow. 

With Best Regards,

Jozef

[ikeryo]

Dear Jozef,

Thank you for your reply!

The NTSX2102 is designed for 1:1 connection system between controller and device. I see.

Is there a level-shifter suitable for connecting multiple devices?

best regards,

Ryo

[JozefKozon]

Dear Ryo-san,

do you need same number of devices on each side? If yes please see this link for NTS030x VLTs family. If you need different number of devices on each side, please see this link for a portfolio of our multiplexers and switches.

With Best Regards,

Jozef