INA190A2IRSWT datasheet(26/41 Pages) TI1

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Time (250 Ps/div)

0 V

D030

Enable

Output

OUTMIN

MIN

SENSE

GAIN

SENSE

MAX

GAIN

INA190

SBOS863C – MARCH 2018 – REVISED APRIL 2019

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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. Using Equation 6, for the given

design parameters the maximum value for RSENSE is calculated to be 1.321 kΩ.

(6)

However, because this value exceeds the maximum recommended value for RSENSE, a resistance value of 1 kΩ

must be used. When operating at the minimum current value, IMIN the output voltage must be greater than the

swing to GND (VSN), specification. For this example, the output voltage at the minimum current is calculated

using Equation 7 to be 25 mV, which is greater than the value for VSN.

(7)

8.2.3 Application Curve

Figure 45 shows the output of the device when disabled and enabled while measuring a 40-µA load current.

When disabled, the current draw from the device supply and inputs is less than 106 nA.

Figure 45. Output Disable and Enable Response

INA190A2IRSWT Datasheet(PDF) 26 Page - Texas Instruments