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Current monitor IC

Shlomi Yehezkia
Mastermind 6150 points
Other Parts Discussed in Thread: INA226

Hi Team,

 

Does TI have a current monitor IC that can measure a current of 0-5mA with an accuracy of 1uA? maybe the TI part INA226.

The application is low power IC that need to measurement the reel current at any stage.
The bus voltage is 0.9-3.8v.

 

This is my calculation :

 

From the INA226 data sheet:

FS = 160uV

ADC : 16 bit

1 LSB = 2.5uV

 

Assuming I use a high side shunt of 5 ohm (I can allow such a high resistance as I will have a maximum current of 5mA and in most cases a current closer to 0.5mA) – this means that the voltage that is seen on the shunt is between 2.5mV and 25mV

 

I need to measure the low currents when I am at 0.5mA peak current – which means a range of 0-2.5mV on the resistor.

2.5uV LSB means I can measure a current change of even 0.5uA

 

 


Thanks,

Shlomi

  • 0
    TI__Expert 4595 points

    Hi Yehezkia,

    INA226 is an Ultra precision Current Shunt monitor but it's bias currents are typically 10uA which will create inaccuracies measuring 1uA of load current. Please take a look at this TI desgin TIPD135 - 10uA-100mA, 0.05% Error, High-Side Current Sensing Solution Reference Design and also refer to the Current Shunt Monitor FAQs on the top of this page.