7.2.2.3 Application Curve

Figure 7-11 shows the typical example output response of a speaker with 4Ω impedance measurement from

20Hz to 20kHz.

Re

Impedance at

Resonance

Inductive Rise

(Le)

Frequency (Hz)

20

100

500

1000

10000

20000

4

12

16

20

24

28

Figure 7-11. Speaker Impedance Measurement

7.3 Power Supply Recommendations

The INA790x makes accurate measurements beyond the connected power-supply voltage (VS) because the

inputs (IN+ and IN–) operate anywhere between –4V and +110V, independent of VS. For example, the VS power

supply equals 5V and the common-mode voltage of the measured shunt can be as high as 110V. Although the

common-mode voltage of the input can be beyond the supply voltage, the output voltage range of the INA790x is

constrained to the supply voltage.

Place the power-supply bypass capacitor as close as possible to the supply and ground pins. The recommended

value of this bypass capacitor is 0.1μF. Additional decoupling capacitance can be added to compensate for

noisy or high-impedance power supplies. If the INA790x output is set to mid-supply, then take extreme care to

minimize noise on the power supply.

7.4 Layout

7.4.1 Layout Guidelines

• This device is specified for current handling of up to 50A over the entire –40°C to +125°C temperature range

using a 2oz copper pour for the input power plane, as well as no external airflow passing over the device.

INA790A, INA790B

SBOSAA6B – MAY 2024 – REVISED JULY 2025

www.ti.com

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