INA181 datasheet(33/62 Pages) TI2

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8.4 Layout

8.4.1 Layout Guidelines

• Connect the input pins to the sensing resistor using a Kelvin or 4-wire connection. This connection technique

makes sure 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 resistor, any additional high-current carrying impedance can

cause significant measurement errors.

• Place the power-supply bypass capacitor as close as possible to the device power supply and ground pins.

The recommended value of this bypass capacitor is 0.1 µF. Additional decoupling capacitance can be added

to compensate for noisy or high-impedance power supplies.

• When routing the connections from the current sense resistor to the device, keep the trace lengths as close

as possible to minimize any impedance mismatch..

8.4.2 Layout Example

GND

IN–

IN+

Current

Sense

OUT

RSHUNT

Direction of Positive

Current Flow

VIA to Ground

Plane

Power-Supply, VS

2.7 V to 5.5 V

CBYPASS

REF

Connect REF to low

impedance voltage reference

or to GND pin if not used.

Bus Voltage:

–0.2 V to +26 V

Figure 8-11. Single-Channel Recommended Layout (SC70)

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INA181, INA2181, INA4181

SBOS793H – APRIL 2017 – REVISED NOVEMBER 2023

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INA181 Datasheet(PDF) 33 Page - Texas Instruments