LP5569: Maximum value of pull-up resistor in CLK pin when set as CLK master

Bruno Lau Costa

Part Number: LP5569

Hi there,

I'm working with more than one LP5569, and want to synchronize them setting the CLK of one of the drivers as output + adding a pull-up resistor.

My device has a low power budget, what makes me think in minimizing the current consumption on such resistor.

Is there a maximum recommended value for this component? The 6.04k resistor of the EVM seems somehow too small for our use case.

Thanks for helping,

Bruno

over 4 years ago

0 Frank Qiu over 4 years ago

TI__Genius 15776 points

Hi Monet could u help in this case

0 Monet Xu over 4 years ago

TI__Genius 9255 points

Hi Bruno,

The is not an detail value about the maximum of pullup resistor. An More than 10 K resistor will also be OK.

When choose the bigger pullup resistor, please take care of the output high level voltage and make sure it normally.

Best Regard

Monet Xu

0 Bruno Lau Costa over 4 years ago in reply to Monet Xu

Prodigy 150 points

Hi, Monet, thanks

Do you think a 100k resistor with a high level of 3.3V is ok for the CLK pin?

Thanks,

0 Frank Qiu over 4 years ago in reply to Bruno Lau Costa

TI__Genius 15776 points

Hi Monet please keep following this case.

+1 Monet Xu over 4 years ago in reply to Bruno Lau Costa

TI__Genius 9255 points

Hi Bruno,

It depends on your PCB layout and i2c communication circuit and it impacts the rising time and fall time of SDA/SCL. I will suggest that after change the pullup resistor, please test the rising time and fall time of I2C to check whether it meet the spec. If it meet the request well, 100k will be OK otherwise decrease the value of pullup resistor. This will be more secure for your application.

Best Regard

Monet Xu

Power management

Power management forum

LP5569: Maximum value of pull-up resistor in CLK pin when set as CLK master