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High side Current monitor IC needs 1V of "headroom"?

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treez

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Hello,
The LT1787 high side current monitor IC seems to need at least 1V of "headroom" between the "Vout" pin and the "Vs+" pin.
This is seen from the LTspice simulation model of LT1787.

However, the LT1787 datasheet makes no mention of this 1V of headroom.
How can I tell what the exact headroom is from the datasheet?

LT1787 DATASHEET:
http://cds.linear.com/docs/en/datasheet/1787fc.pdf


LT1787 example schematic and LTspice simulation attached.
 

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  • LT1787 headroom.txt
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Page 3:

VOMAX Maximum Output Voltage Vs+ - 0.75V
 
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Yes, I saw that, but if you run the simulation, you see that it doesn't work right if its only 0.75V...it has to be at least 1V...so I wonder is the simulation model wrong, or is the datasheet wrong?
 

The datasheet lists that as a "typical" value. No min or max is given.
 
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I must admit I am baffled as to why the datasheet should omit this extremely crucial parameter...this parameter should be right up on the top page.
I am just wondering if a lower-component-count solution could be had with INA282 monitor IC?
https://www.ti.com/lit/ds/symlink/ina282.pdf
 

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