PG (power good) on low EN (chip disable)

Vladimir Aparin

Other Parts Discussed in Thread: LP3988

What will be on PG (power good) on LP3988IMF-3.0/NOPB when EN is low (Chip is disabled) and Vin < 90%?
On block scheme in datasheet PG is not depend on EN.

over 10 years ago

0 Donald Jones over 10 years ago

TI__Mastermind 22610 points

PG pin is disabled (off / hi-z) when Ven is low.

Following three images are scope shots where LP3988 PG pin is biased from Vin (5V) thru a 50k ohm pull-up R, while EN pin is toggled.

7652.LP3988_PG-vs-Ven-.tif

0576.LP3988_PG-vs-Ven on-.tif

7080.LP3988_PG-vs-Ven off-.tif

0 Donald Jones over 10 years ago in reply to Donald Jones

TI__Mastermind 22610 points

In case the .tif images fail here are low-rez .bmp images. PG pin output is the green trace ...

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Over-view of 'ON-OFF' transitions

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Close-up for 'ON' transition

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Close-up for 'OFF' transition

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Power management

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PG (power good) on low EN (chip disable)