DS90UB935-Q1: How can the I2C connection between image SENSOR and DS90UB935-Q1 be achieved?

luo Mandy

Part Number: DS90UB935-Q1

Tool/software:

Since the I2C of the image sensor is powered by 3.3V, the I2C of the DS90UB935 is powered by 1.8V. How can the I2C connection between two chips be achieved? If needed, I can provide the schematic diagram. Please help me take a look.

2 months ago

0 Hamzeh Jaradat 2 months ago

TI__Guru** 107710 points

Hello Luo,

In this case you would need a level translator (shifter) from 1.8V to 3.3V. Such as the TCA9517A data sheet, product information and support | TI.com

0 luo Mandy 2 months ago in reply to Hamzeh Jaradat

Prodigy 35 points

Is there any other way?

I referred to the I2C Data and Clock Pins section in the 935 manual. These pins are pulled up to either the 1.8V or 3.3V supply rail, depending on the IDX setting. Could it be possible to solve the problem by simply modifying the resistance values of RHIGH and RLOW?As shown in the figure below：

0 Hamzeh Jaradat 2 months ago in reply to luo Mandy

TI__Guru** 107710 points

You may connect the 935 I2C pins to either 1.8V or to 3.3V using the right resistor combinations as shown in the Table 6-11 in the datasheet.

0 luo Mandy 2 months ago in reply to Hamzeh Jaradat

Prodigy 35 points

Yes, I need to connect the 935 I2C pins to 3.3V. Can I use the combination of RHIGH 82.5K and RLOW 102K from Table 6-11 in the datasheet to convert the 935 I2C pins to 3.3V? Am I understanding this correctly?

+1 Hamzeh Jaradat 2 months ago in reply to luo Mandy

TI__Guru** 107710 points

Yes, you can do that. This is okay.

But you need to make sure your register 0x02[0] on the SER is set to 3.3V as well.

0 luo Mandy 2 months ago in reply to Hamzeh Jaradat

Prodigy 35 points

OK! Thank you very much.

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DS90UB935-Q1: How can the I2C connection between image SENSOR and DS90UB935-Q1 be achieved?