1.99

1.995

2

2.005

±50

±25

0

25

50

75

100

125

150

Temperature (

ƒC)

C030

INA250A1, INA250A2, INA250A3, INA250A4

SBOS511B – APRIL 2015 – REVISED DECEMBER 2015

www.ti.com

Feature Description (continued)

7.3.3 Temperature Stability

System calibration is common for many industrial applications to eliminate initial component and system-level

errors that can be present. A system-level calibration can reduce the initial accuracy requirement for many of the

individual components because the errors associated with these components are effectively eliminated through

the calibration procedure. Performing this calibration can enable precision measurements at the temperature in

which the system is calibrated, but as the system temperature changes as a result of external ambient changes

or due to self heating, measurement errors are reintroduced. Without accurate temperature compensation used

in addition to the initial adjustment, the calibration procedure is not effective in accounting for these temperature-

induced changes. One of the primary benefits of the very low temperature coefficient of the INA250 (including

both the integrated current-sensing resistor and current-sensing amplifier) is ensuring that the device

measurement remains highly accurate, even when the temperature changes throughout the specified

temperature range of the device.

For the integrated current-sensing resistor, the drift performance is shown in Figure 32. Although several

temperature ranges are specified in the Electrical Characteristics table, applications operating in ranges other

than those described can use Figure 32 to determine how much variance in the shunt resistor value can be

expected. As with any resistive element, the tolerance of the component varies when exposed to different

temperature conditions. For the current-sensing resistor integrated in the INA250, the resistor does vary slightly

more when operated in temperatures ranging from –40°C to 0°C than when operated from 0°C to 125°C.

However, even in the –40°C to 0°C temperature range, the drift is still quite low at 25 ppm/°C.

Figure 32. Sensing Resistor vs Temperature

An additional aspect to consider is that when current flows through the current-sensing resistor, power is

dissipated across this component. This dissipated power results in an increase in the internal temperature of the

package, including the integrated sensing resistor. This resistor self-heating effect results in an increase of the

resistor temperature helping to move the component out of the colder, wider drift temperature region.

14

Submit Documentation Feedback

Copyright © 2015, Texas Instruments Incorporated

Product Folder Links: INA250A1 INA250A2 INA250A3 INA250A4