Other Parts Discussed in Thread: INA282, , TPS22959
Hello Peter,
we have discussed in a previous conversation about INA139 to sense 10A current and INA282 to sense 10mA to 50mA, as shown in the picture below.
I want have the possibility to disconnect this part of circuit, i mean INA282, INA139 and Rshunt because it's absolutely required in my application to measure a third current of 70uA. for information, my application contain 3 consecutive phase of operation :
Phase 1 : sense 10A
Phase 2 : sense 50mA
Phase 3 : sense an ultra low current of 70uA. this current will be sense with an external module (NI9203) able to sense between +-20mA (i don't know if i could find a current sensor from Texas Instruments able to mesure this current).
My big issue, is it possible to add 2 switch as shown in the picture below to disconnect this circuit when i am mesuring the 70uA current. Already, I know that logically, it is not advisable to put anything, beause it will distort the measure.
if i use the TPS22959 Switch to disconnect the circuit, it have an ultra low Ron resistance so normaly he will not influence to much the measure.
1 - Do you think that it could be possible to add this kind of CI with the current sensor.
2 - Does it exist at Texas Instruments a circuit able to measure a current arroud 70uA. the issue is to be able to integre it in the same board.
Thank you.
