TCA9543A: A0, A1 pins and pull-up resistors

Silvan Sommer

Part Number: TCA9543A

Tool/software:

Hello

A0 and A1 pins are used for hardware bus selection. Now I dont need that harware selection feature so can you please tell me, should i tie this pins directly to GND or to Vcc ?

I think for normal speed arduino I2C communication, 10KOhm pull-up resistors for I2C input and both selectable output buses should be a good value right?

Thanks

Silvan

8 months ago

0 Clemens Ladisch 8 months ago

Guru 320720 points

The A0/A1 pins can be connected directly to V_CC or GND.

0 Nir Gilgur 8 months ago

TI__Mastermind 23975 points

Hello Silvan,

If they are not being used then you should tie them to ground.
10k pull up resistors will be fine here.

Thanks,

Nir

0 Silvan Sommer 8 months ago in reply to Nir Gilgur

Intellectual 320 points

Hello Nir

Thanks.

I think, this is only for hardware selection right? I can still write to the control register of the multiplexer and either choose to activate sub-bus 1 or sub-bus 2 or both right? This function will still work even after I tie the A1,A0 pin to GND?

Best regards

Silvan

0 Clemens Ladisch 8 months ago in reply to Silvan Sommer

Guru 320720 points

Yes; the A0/A1 pins affect only the I²C device address.

0 Silvan Sommer 8 months ago in reply to Clemens Ladisch

Intellectual 320 points

Hello Clemens

What do you mean with affect the I2C device address? Which I2C address then has the chip if i tie both to GND?

I thought this pins were there to hardware choose if i want to activate the sub-bus 1 or sub-bus 2.

Thanks

Silvan

+1 Nir Gilgur 8 months ago in reply to Silvan Sommer

TI__Mastermind 23975 points

Hello Silvan,

Yes, even though the address pins are still tied to ground you can still control the switches via the I2C bus.

Thanks,

Nir

Interface

Interface forum

TCA9543A: A0, A1 pins and pull-up resistors