Sensing & measuring current from 2.8V to 11V voltage battery

[treez]

Hello,
We need to sense and measure the current from a battery which could be anywhere between 2.8V and 11V terminal voltage ...as follows...

https://i41.tinypic.com/2hf5teu.jpg

....an ADC of a micro will end up sensing the output voltage of whichever current sense method that gets used.

Can you suggest a relatively cheap current sense method for this setup?
(the ZXCT1009 cannot work down to 2.8V)

The current will be anywhere between 50mA and 2A.

 

[muneeb.khan]

Hello,
We need to sense and measure the current from a battery which could be anywhere between 2.8V and 11V terminal voltage ...as follows...

https://i41.tinypic.com/2hf5teu.jpg

....an ADC of a micro will end up sensing the output voltage of whichever current sense method that gets used.

Can you suggest a relatively cheap current sense method for this setup?
(the ZXCT1009 cannot work down to 2.8V)

The current will be anywhere between 50mA and 2A.

the cheapest method of current sensing is thrown sense(shunt) resistor. and there will be two methods the high side and low side, low side method will be easier. I have made a current sensor with this method and it gives pretty nice results with resolution of 10mA.

 

[crutschow]

So why not use the LT6106 as shown in the referenced schematic? Its price is only slightly over a $1US.

 

[treez]

LT6106 will not go down as far as 2.8V.
I believe the LT1787 may be the one?

Do you think this schematic is ok? (attached)

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

View attachment LT1787 20v.pdf

 

[crutschow]

According to the data sheet the LT6106 will go down to 2.7V.