LP5522: Floating CTRL input

Azriel Kurtz

Part Number: LP5522

Is it legitimate to leave the CTRL input of the LP5522 LED driver floating briefly when the chip is powered on?

I am using a microcontroller to pull the pin down to 0, but this only happens a few seconds after the driver chip is powered on. Is this liable to cause a glitch, or does the chip have an internal pull-down on the CTRL pin?

Thank you,

Azriel Kurtz

over 5 years ago

0 Yuting Shao over 5 years ago

TI__Genius 13001 points

Hi Azriel,

It's necessary to connect the CTRL pin to a certain volatge.

BR,

Robin

0 John Griffith over 5 years ago in reply to Yuting Shao

TI__Mastermind 21800 points

HI Robin,

Is it then correct to say that the CTRL pin does not have either an internal pull up or an internal pull down on the pin? And therefore leaving it floating results in an unpredictable state?

John

0 Yuting Shao over 5 years ago in reply to John Griffith

TI__Genius 13001 points

Hi,

It has internal pull-down resister, but it would be safer to have external pull-down resister.

BR,

Robin

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LP5522: Floating CTRL input