UCD90120A Open Drain Output

Kyle Slightom

Other Parts Discussed in Thread: UCD90120A

Hi,

Is it acceptable to use the open drain outputs of the UCD90120A at voltages less than 3.3V or would a resistor divider be needed? We would like to interface a GPIO part to another parts 1.8V logic enable.

Thanks,
Kyle

over 7 years ago

0 Fery Feng over 7 years ago

TI__Intellectual 2270 points

Hi Kyle,

As you can see in the UCD90120A datasheet, the analog input voltage range of each MON PIN is 0~2.5V, so once you want to monitor the voltage greater than 2.5V, you need a resistor divider, and configure the related vout scale in GUI.

Thank you.

0 Kyle Slightom over 7 years ago in reply to Fery Feng

Prodigy 50 points

Hi Ferry,

Thanks for the response. My question is regarding the allowable output voltage for a GPIO. The VDDIO voltage is 3.3V but I would like to drive a 1.8V input on a separate part. Can I use the GPIO configured as an output in open drain mode and pull the driver up to 1.8V or do I need to pull it up to 3.3V?

Thanks,
Kyle

0 Zhiyuan Hu over 7 years ago in reply to Kyle Slightom

TI__Genius 9845 points

Yes. In open-drain mode, you can pull up to 1.8V.

Power management

Power management forum

UCD90120A Open Drain Output