SC18IS602: I2C Address setting

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SC18IS602: I2C Address setting

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emilzachariageo
Contributor II

Hello NXP Team,

Does the A0, A1 and A2 address setting pins of the IC has internal pull up?

I had added only 0E pull down option for these 3 pins with which I get 0x28 I2C address for the IC.

Is it possible to get any other address for the IC by removing any of these resistors?

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reyes
NXP TechSupport
NXP TechSupport

Hi,

Does the A0, A1 and A2 address setting pins of the IC has internal pull up?

[Answer] No, desired logic level need to be driven externally either by connecting external pull-up to referenced to VCC, or connecting them to external GND. You should not leave these pns unconnected.

 

I had added only 0E pull down option for these 3 pins with which I get 0x28 I2C address for the IC.

Is it possible to get any other address for the IC by removing any of these resistors?

[Answer] This is correct, the slave address of the SC18IS602B is comprised of a fixed and a programmable part. The programmable part of the slave address enables the maximum possible number of such devices to be connected to the I2C-bus. Since the SC18IS602B has three programmable address bits (defined by the A2, A1, and A0 pins), it is possible to have eight of these devices on the same bus.

 

The slave address is: 0 1 0 1 A2 A1 A0 R/W

 

If A2, A1 and A0 are tied to ground, the address would be 0 1 0 1 0 0 0 R/W (7-bit 0x28).

If for example you connect A1 pin to VCC trough an external pull-up and leave A2 and A0 pins connected to GND, the address would be 0 1 0 1 0 1 0 R/W (7-bit 0x2A).

 

You can find more details on section 7.1.1 of the device datasheet: https://www.nxp.com/docs/en/data-sheet/SC18IS602B.pdf

Regards,

Jose

NXP Semiconductors

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emilzachariageo
Contributor II

Hi Jose,

Thanks for confirming of the absence of internal pull ups.

We shall proceed accordingly.

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