INA239 datasheet(16/47 Pages) TI

16 / 47 page

ms. The resolution in programming the conversion delay is 2 ms. The conversion delay is set to 0 by default.

Conversion delay can assist in measurement synchronization when multiple external devices are used for

voltage or current monitoring purposes. In applications where an time aligned voltage and current measurements

are needed, two devices can be used with the current measurement delayed such that the external voltage and

current measurements will occur at approximately the same time. Keep in mind that even though the internal

time base for the ADC is precise, synchronization will be lost over time due to internal and external time base

mismatch.

7.3.4.1 Low Latency Digital Filter

The device integrates a low-pass digital filter that performs both decimation and filtering on the ADC output

data, which helps with noise reduction. The digital filter is automatically adjusted for the different output data

rates and always settles within one conversion cycle. The user has the flexibility to choose different output

conversion time periods TCT from 50 µs to 4.12 ms. With this configuration the first amplitude notch appears

at the Nyquist frequency of the output signal which is determined by the selected conversion time period and

defined as fNOTCH= 1 / (2 x TCT). This means that the filter cut-off frequency will scale proportionally with the data

output rate as described. ADC Frequency Response shows the filter response when the 1.052 ms conversion

time period is selected.

−60

−50

−40

−30

−20

−10

100

10k

100k

Frequency (Hz)

G001

Conversion time = 1.052 ms, single

conversion only

Figure 7-3. ADC Frequency Response

7.3.4.2 Flexible Conversion Times and Averaging

ADC conversion times for shunt voltage, bus voltage and temperature can be set independently from 50 μs to

4.12 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 INA239-Q1 effective resolution of the ADC can be increased by increasing the conversion

time and increasing the number of averages. Figure 7-4 and Figure 7-5 shown below illustrate the effect of

conversion time and averaging on a constant input signal.

INA239-Q1

SLYS028A – MAY 2020 – REVISED JUNE 2021

www.ti.com

Submit Document Feedback

Product Folder Links: INA239-Q1

INA239 датащи(PDF) 16 Page - Texas Instruments

INA239 датащи(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

датащи скачать

ссылки URL