+

±

Buffer

Current

Feedback

RL

R1

R1

Bias

48-V

Supply

Load

IN+

IN±

5 V

OUT

GND

14

INA290

SBOS961 – JUNE 2020

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Table 1. Fixed Gain Resistor

GAIN

R1

RL

20 (V/V)

25 kΩ

500 kΩ

50 (V/V)

10 kΩ

500 kΩ

100 (V/V)

10 kΩ

1000 kΩ

200 (V/V)

5 kΩ

1000 kΩ

500 (V/V)

2 kΩ

1000 kΩ

7.3.1.5 Wide Supply Range

The INA290 operates with a wide supply range from a 2.7 V to 20 V. The output stage supports a full-scale

For a gain of 20 V/V, the maximum differential input acceptable is 1 V.

The offset of the gain of INA290A1 device is ±25 µV, and the INA290A1 is capable of measuring a wide dynamic

range of current up to 92 dB.

7.4 Device Functional Modes

7.4.1 Unidirectional Operation

The INA290 measures the differential voltage developed by current flowing through a resistor that is commonly

referred to as a current-sensing resistor or a current-shunt resistor. The INA290 operates in unidirectional mode

only, meaning it only senses current sourced from a power supply to a system load as shown in Figure 37.

Figure 37. Unidirectional Application

The linear range of the output stage is limited to how close the output voltage can approach ground under zero-

input conditions. The zero current output voltage of the INA290 is very small, with a maximum of GND + 25 mV.

Make sure to apply a sense voltage of (25 mV / Gain) or greater to keep the INA290 output in the linear region of

operation.

7.4.2 High Signal Throughput

With a bandwidth of 1.1 MHz at a gain of 20 V/V and a slew rate of 2 V/µs, the INA290 is specifically designed

for detecting and protecting applications from fast inrush currents. As shown in Table 2, the INA290 responds in

less than 2 µs for a system measuring a 75-A threshold on a 2-mΩ shunt.