INA210 datasheet(16/50 Pages) TI2

16 / 50 page

7.4 Device Functional Modes

7.4.1 Averaging Function

The INA3221 includes three channels to monitor up to three independent supply buses; however, multichannel

monitoring sometimes results in poor shunt-resistor placement. Ideally, shunt resistors are placed as close as

possible to the corresponding channel input pins. However, because of system layout and multiple power-supply

rails, one or more shunt resistors can require being located further away, thus presenting potentially larger

measurement errors. These errors result from additional trace inductance and other parasitic impedances

between the shunt resistor and input pins. Longer traces also create an additional potential for coupling noise

into the signal if the traces are routed near noise-generating sections of the board.

The INA3221 averaging function mitigates this potential problem by limiting the impact that any single

measurement has on the averaged value of each measured signal. This limitation reduces the influence that

noise has on the averaged value, thereby effectively creating an input-signal filter.

The averaging function is illustrated in Figure 7-5. Operation begins by first measuring the shunt input signal

on channel 1. This value is then subtracted from the previous value that was present in the corresponding data

output register. This difference is then divided by the value programmed by the averaging mode setting (AVG2-0,

Configuration register bits 11-9) and stored in an internal accumulation register. The computed result is then

added to the previously-loaded data output register value, and the resulting value is loaded to the corresponding

data output register. After the update, the next signal to be measured follows the same process. The larger

the value selected for the averaging mode setting, the less impact or influence any new conversion has on the

average value, as shown in Figure 7-6. This averaging feature functions as a filter to reduce input noise from the

averaged measurement value.

AVG #

New

Sample

Output

Figure 7-5. Averaging Function Block Diagram

1000

2000

3000

4000

5000

6000

7000

Samples

1 Average

16 Averages

1024 Averages

G020

Figure 7-6. Average Setting Example

INA3221

SBOS576C – MAY 2012 – REVISED SEPTEMBER 2025

www.ti.com

Submit Document Feedback

Product Folder Links: INA3221

INA210 Datasheet(PDF) 16 Page - Texas Instruments

INA210 Datasheet(HTML) 16 Page - Texas Instruments

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50

Datasheet Download

Link URL