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

INA280 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 choice of gain, value of the maximum

current the 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.

SP

SENSE

MAX

V

R

<

I

GAIN

u

(6)

For this design example, a value of 15 mΩ is selected because, while the 15 mΩ is less than the maximum value

calculated, 15 mΩ is still large enough to give adequate signal at the current-sense amplifier output.

8.2.2.1 Overload Recovery With Negative VSENSE

The INA280 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 once 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)

A2 Device VOUT (1 V/div)

VSENSE (20 mV/div)

INA2

Figure 8-3. INA280 Output Response

www.ti.com

INA280

SBOSA19 – OCTOBER 2020

Copyright © 2020 Texas Instruments Incorporated

Submit Document Feedback

17

Product Folder Links: INA280