INA290 datasheet(22/45 Pages) TI2

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8.2.1 Design Requirements

VSUPPLY is set to 5 V and the common-mode voltage set to 54 V. Table 8-3 lists the design setup for this

application.

Table 8-3. Design Parameters

DESIGN PARAMETERS

EXAMPLE VALUE

INAx290 supply voltage

5 V

High-side supply voltage

5 V

Maximum sense current (IMAX)

5 A

Gain option

50 V/V

8.2.2 Detailed Design Procedure

The maximum value of the current-sense resistor is calculated based on the choice of gain, value of the

maximum current to be sensed (IMAX), and the power-supply voltage (VS). When operating at the maximum

current, the output voltage must not exceed the positive output swing specification, VSP. Under the given design

parameters, Equation 6 calculates the maximum value for RSENSE as 19.2 mΩ.

SENSE

MAX

GAIN

(6)

Although 15 mΩ is less than the maximum value calculated, 15 mΩ is selected for this design example because

this value is still large enough to provide an adequate signal at the current-sense amplifier output.

8.2.2.1 Overload Recovery With Negative VSENSE

The INAx290 is a unidirectional current-sense amplifier that is meant to operate with a positive differential input

voltage (VSENSE). If negative VSENSE is applied, the device is placed in an overload condition and requires time

to recover when VSENSE returns positive. The required overload recovery time increases with more negative

VSENSE.

8.2.3 Application Curve

Figure 8-3 shows the output response of the device to a high-frequency sinusoidal current.

Time (10Ps/div)

INA290A2 VOUT (1 V/div)

VSENSE (20 mV/div)

Figure 8-3. INAx290 Output Response

INA290, INA2290, INA4290

SBOS961C – JUNE 2020 – REVISED JUNE 2021

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INA290 Datasheet(PDF) 22 Page - Texas Instruments