8.3 Power Supply Recommendations

Figure 8-2 shows that the device input circuitry can accurately measure signals on common-mode voltages

beyond the power-supply voltage, VS. For example, the voltage applied to the vs. power supply pin can be 5 V,

whereas the bus power-supply voltage being monitored (the common-mode voltage) can be as high as 48 V.

The device can also withstand the full -0.3 V to 48 V range at the input pins, regardless of whether the device

has power applied or not.

Place the required power-supply bypass capacitors as close as possible to the supply and ground pins of the

device to ensure stability. A typical value for this supply bypass capacitor is 0.1 µF. Applications with noisy or

high-impedance power supplies can require additional decoupling capacitors to reject power-supply noise.

8.4 Layout

8.4.1 Layout Guidelines

Connect the input pins (IN+ and IN–) to the sensing resistor using a Kelvin connection or a 4-wire connection.

These connection techniques ensure that only the current-sensing resistor impedance is detected between

the input pins. Poor routing of the current-sensing resistor commonly results in additional resistance present

between the input pins. Given the very low ohmic value of the current-sensing resistor, any additional high-

current carrying impedance causes significant measurement errors. Place the power-supply bypass capacitor as

close as possible to the supply and ground pins.

8.4.2 Layout Example

CBYPASS

Supply Voltage (VS):

1.7 V to 5.5 V

Bus Voltage

RPULLUP3

I

2C Voltage:

1.2 V to 5.5 V

Device Address:

Connect to SDA,

SCL, VS, or GND

VIA to GND

Plane

I

2C Clock

I

2C Alert

I

2C Data

RPULLUP2

RPULLUP1

Load

4

IN+

IN-

GND

VS

ALERT

A0

SDA

SCL

3

2

6

5

7

8

1

SOT23-8

Figure 8-5. INA232 Layout Example DDF (High Side)

INA232

SBOSAA2 – DECEMBER 2022

www.ti.com

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