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INA139-Q1

INA169-Q1

SGLS185E

– SEPTEMBER 2003 – REVISED MAY 2011

www.ti.com

APPLICATION INFORMATION

The transfer function for the INA139 is:

measurement amplifier in this application is:

The maximum differential input voltage for accurate measurements is 0.5 V, which produces a 500-

μA output

current. A differential input voltage of up to 2 V will not cause damage. Differential measurements (pins 3 and 4)

must be unipolar with a more-positive voltage applied to pin 3. If a more-negative voltage is applied to pin 3, the

output current, IO, will be zero, but it will not cause damage.

Figure 9. Basic Circuit Connections

BASIC CONNECTION

closely as possible to the shunt resistor to minimize any resistance in series with the shunt resistance. The

could flow in the ground connections, affecting the measurement accuracy.

No power-supply bypass capacitors are required for stability of the INA139. However, applications with noisy or

high-impedance power supplies may require decoupling capacitors to reject power-supply noise; connect bypass

capacitors close to the device pins.

6

Copyright

© 2003–2011, Texas Instruments Incorporated