TCA9406: Use a TCA9406 with multiple I2C devices

ee06091

Part Number: TCA9406

Hi,

I need to add a 1.8V slave to my design. After looking for an I2C level translator, TCA9406 seems to be a good candidate for the job however I'm little confuse whether it is able to upper the voltage from VCCA to VCCB or lower from VCCA to VCCB.

This is how I think it should be used. ESP32 is a I2C master while INA260 and ICM-20948 are both slaves. INA260 at 3.3V and ICM-20948 at 1.8V.

Is it ok?

Thank you

over 4 years ago

0 BOBBY over 4 years ago

TI__Guru 59680 points

Hello,

TCA9406 can provide the level shifting you require. Though another alternative is PCA9306 which has many package options and is more price competitive than TCA9406.

From the schematic, the pin our looks good and the OE is referenced to VccA. So I don't see any problems here.

-Bobby

0 ee06091 over 4 years ago in reply to BOBBY

Intellectual 340 points

Thank you,

And it is ok not to use R pullup on 1.8V side?

0 BOBBY over 4 years ago in reply to ee06091

TI__Guru 59680 points

Yes, that's fine since the 1.8V side has internal 10k pull up resistors. They do get turned off if the OE is low but it seems this won't be a concern since it's tied directly to VccA.

-Bobby

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TCA9406: Use a TCA9406 with multiple I2C devices