INA190A3NDDFREP datasheet(27/37 Pages) TI

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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. For the given design parameters,

Equation 6 determines that the maximum value for RSENSE is 1.321 kΩ.

SENSE

MAX

GAIN

(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, Equation 7 determines that the output voltage at the

minimum current is 25 mV, which is greater than the value for VSN.

OUTMIN

MIN

SENSE

GAIN

(7)

8.2.3 Application Curve

Figure 8-7 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.

Time (250 Ps/div)

0 V

D030

Enable

Output

Figure 8-7. Output Disable and Enable Response

9 Power Supply Recommendations

The input circuitry of the INA190-EP accurately measures beyond the power-supply voltage, VS. For example,

VS can be 5 V, whereas the bus supply voltage at IN+ and IN– can be as high as 40 V. However, the output

voltage range of the OUT pin is limited by the voltage on the VS pin. The INA190-EP also withstands the full

differential input signal range up to 40 V at the IN+ and IN– input pins, regardless of whether the device has

power applied at the VS pin. There is no sequencing requirement for VS and VIN+ or VIN–.

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INA190-EP

SBOSA74 – MAY 2022

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INA190A3NDDFREP Datasheet(PDF) 27 Page - Texas Instruments