Continue to Site

Welcome to EDAboard.com

Welcome to our site! EDAboard.com is an international Electronics Discussion Forum focused on EDA software, circuits, schematics, books, theory, papers, asic, pld, 8051, DSP, Network, RF, Analog Design, PCB, Service Manuals... and a whole lot more! To participate you need to register. Registration is free. Click here to register now.

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

Status
Not open for further replies.
T

treez

Guest
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.
 

Attachments

  • LT1787 headroom.pdf
    13.1 KB · Views: 118
  • LT1787 headroom.txt
    977 bytes · Views: 61

Page 3:

VOMAX Maximum Output Voltage Vs+ - 0.75V
 
  • Like
Reactions: treez

    T

    Points: 2
    Helpful Answer Positive Rating
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.
 
  • Like
Reactions: treez

    T

    Points: 2
    Helpful Answer Positive Rating
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
 

Status
Not open for further replies.

Part and Inventory Search

Welcome to EDABoard.com

Sponsor

Back
Top