u

Power Register

Current Register

Voltage Register

Alert Register

I

2C or SMBus

Compatible

Interface

VBUS

ADC

V

I

A0

A1

ALERT

SDA

SCL

VS

IN+

GND

IN-

12

INA260

SBOS656C – JULY 2016 – REVISED DECEMBER 2016

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8 Detailed Description

8.1 Overview

The INA260 is an integrated shunt digital current sense amplifier with an I2C- and SMBus-compatible interface. It

provides digital current, voltage, and power readings necessary for accurate decision-making in precisely-

controlled systems. Programmable registers allow flexible configuration for conversion times as well as

continuous-versus-triggered operation. Detailed register information appears at the end of this data sheet,

beginning with Table 4. See the Functional Block Diagram section for a block diagram of the INA260 device.

8.2 Functional Block Diagram

8.3 Feature Description

8.3.1 Integrated Shunt Resistor

The INA260 features a precise, low-drift, current-sensing resistor to allow for precision measurements over the

entire specified temperature range of –40°C to +125°C. The integrated current-sensing resistor ensures

measurement stability over temperature as well as simplifying printed-circuit board (PCB) layout difficulties

common in high precision current sensing measurements.

The onboard current-sensing resistor is designed as a 4-wire (or Kelvin) connected resistor that enables accurate

measurements through a force-sense connection. The Kelvin connections to the shunt are done internally

eliminating many of the parasitic impedances commonly found in typical very-low sensing-resistor level

measurements. Although the shunt resistor can be accessed through the IN+ and IN– pins, this resistor is not

intended to be used as a stand-alone component. The INA260 is internally calibrated to ensure that the current-

sensing resistor and current-sensing amplifier are both precisely matched to one another.

The INA260 has approximately 4.5 mΩ of total resistance between the IN+ and IN- pins. 2 mΩ of this total

package resistance is a precisely-controlled resistance from the Kelvin-connected current-sensing resistor used

by the internal analog to digital converter (ADC). The power dissipation requirements of the system and package

are based on the total 4.5-mΩ package resistance. The heat dissipated across the package when current flows

through the device ultimately determines the maximum current that can be safely handled by the package. The

current consumption of the silicon is relatively low, leaving the total package resistance carrying the high load

current as the primary contributor to the total power dissipation of the package. The maximum safe-operating

current level is set to ensure that the heat dissipated across the package is limited so that no damage to the

resistor or the package itself occurs or that the internal junction temperature of the silicon does not exceed a

150°C limit.