OUT

V+

VIN+

VIN-

PCB Pad

0.1 µF

VIA to Ground Plane

Supply Voltage

Output

PCB Pad

To Bus

Voltage

To Load

RL

GND

RSHUNT

INA139

INA169

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19

INA139, INA169

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SBOS181F – DECEMBER 2000 – REVISED FEBRUARY 2017

Product Folder Links: INA139 INA169

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Copyright © 2000–2017, Texas Instruments Incorporated

10 Layout

10.1 Layout Guidelines

Figure 19 shows the basic connection of the INA139. The input pins (VIN+ and VIN–) must be connected as

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

output resistor, RL, is shown connected between pin 1 and ground. Best accuracy is achieved with the output

voltage measured directly across RL. This is especially important in high-current systems where load current

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 the

bypass capacitors close to the device pins.

10.2 Layout Example

Figure 19. Typical Layout Example