10 Power Supply Recommendations

The input circuitry of the INAx290 device can accurately measure beyond the power-supply voltage. The power

supply can be 20 V, whereas the load power-supply voltage at IN+ and IN– can go up to 120 V. The output

11 Layout

11.1 Layout Guidelines

TI always recommends to follow good layout practices:

• Connect the input pins to the sensing resistor using a Kelvin or 4-wire connection. This connection technique

makes sure that only the current-sensing resistor impedance is detected between the input pins. Poor routing

of the current-sensing resistor commonly results in additional resistance present between the input pins.

Given the very low ohmic value of the current resistor, any additional high-current carrying impedance can

cause significant measurement errors.

• Place the power-supply bypass capacitor as close to the device power supply and ground pins as possible.

The recommended value of this bypass capacitor is 0.1 µF. Additional decoupling capacitance can be added

to compensate for noisy or high-impedance power supplies.

• When routing the connections from the current-sense resistor to the device, keep the trace lengths as short

as possible.

11.2 Layout Example

4

2

IN±

OUT

Current Sense

Output

GND

Load

VIA to Ground

Plane

(2.7 V to 20 V)

5

1

IN+

VS 3

Direction of

Current Flow

Bus Voltage

TI Device

Figure 11-1. Recommended Layout for INA290

INA290, INA2290

SBOS961A – JUNE 2020 – REVISED SEPTEMBER 2020

www.ti.com

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