INA139 Parallel operation

Hello Dror,

Yes, this is acceptable and the currents will sum as expected.  It is recommended to place a small-signal diode in series with each of the outputs in this configuration to ensure that reverse current never flows back into one of the other devices, even if they are powered down or inactive.  I would also recommend a small series resistors (100 Ohms) between the summing point for extra protection.  Just be sure that the total current into the load resistor doesn't create a voltage potential that is greater than the compliance voltages of the current sources. 

Figure 5 shows two units that have shared outputs and a 10kOhm resistor to isolate them.  As mentioned a lower resistor value such as 100Ohms can be used.  The comparator was only for the bidirectional current sensing scheme shown and would not be needed in your application.