PCA9536: p-port I/O

Seishin

Genius 4135 points

Part Number: PCA9536

Hi,

P0-3 has an internal pull-up resistor of 100 kΩ.

P0-3 goes High at startup.(Before register setting)

I want to set the P0-3 output to Low at startup using pull-down resistor.

What is the minimum value of the pull-down resistor?

I want to reduce current consumption.

Best regards,
Seishin

over 7 years ago

0 Matt Mendez over 7 years ago

TI__Intellectual 2885 points

Hello Seishin,

The max resistor you could use to act as a pull-down is 19 kΩ. I calculated this using a voltage divider equation. For a low to be seen on P0-3, the voltage must be at 0.8 V or lower. 19 kΩ causes the voltage to be at 0.8 V. Any smaller resistor should create a smaller voltage this driving the port low.

0 Seishin over 7 years ago in reply to Matt Mendez

Genius 4135 points

Dear Matt,

Thank you for your reply.

Best regards,

Seishin

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PCA9536: p-port I/O