data output rate as described. Figure 7-5 shows the filter response when the 1.052 ms conversion time period is

selected.

−60

−50

−40

−30

−20

−10

0

1

10

100

1k

10k

100k

Frequency (Hz)

G001

Conversion time = 1.052 ms, single

conversion only

Figure 7-5. ADC Frequency Response

7.3.5.2 Flexible Conversion Times and Averaging

ADC conversion times for bus voltage can be set independently from 50 μs to 4.12 ms. The total conversion

time for current includes an additional conversion time for temperature, and can be varied from 100 μs to

8.24 ms. The flexibility in conversion time allows for robust operation in a variety of noisy environments. The

device also allows for programmable averaging times from a single conversion all the way to an average of

1024 conversions. The amount of averaging selected applies uniformly to all active measurement inputs. The

ADC_CONFIG register shown in Table 7-6 provides additional details on the supported conversion times and

averaging modes. The INA781 effective resolution of the ADC can be increased by increasing the conversion

time and increasing the number of averages. Figure 7-6 and Figure 7-7 shown below illustrate the effect of

conversion time and averaging on a constant input signal.

Number of Conversions

0

2000

4000

6000

8000

10000

Conversion Time: 50 us

Conversion Time: 1.052 ms

Conversion Time: 4.120 ms

Figure 7-6. Noise vs Conversion Time (Averaging = 1)

Number of Conversions

0

2000

4000

6000

8000

10000

Conversion Time: 50 us

Conversion Time: 1.052 ms

Conversion Time: 4.120 ms

Figure 7-7. Noise vs Conversion Time (Averaging = 128)

INA781

SBOSAC0 – JULY 2023

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