INA745AIRELR datasheet(16/50 Pages) TI2

16 / 50 page

The current, bus voltage, and temperature values are immediate results when the number of averages is set to

1 (see Figure 6-7). However, when averaging is used, each ADC measurement is an intermediate result which

is stored in the corresponding averaging registers. Following every ADC sample, the newly-calculated values for

current, voltage, and temperature are appended to the corresponding averaging registers until the set number

of averages is achieved. After all of the samples have been measured, the average current and voltage is

determined, the power is calculated, and the results are loaded to the corresponding output registers where the

results can then be read.

The energy and charge values are accumulated for each conversion cycle. Therefore the INA745x averaging

function is not applied to these.

Calculations for power, charge and energy are performed in the background and do not add to the overall

conversion time.

Q1 =

i1 x t1

Q.. =

i.. x t..

Q.. =

i.. x t..

Q.. =

i.. x t..

Q.. =

i.. x t..

E.. =

p.. x t..

E.. =

p.. x t..

E.. =

p.. x t..

E.. =

p.. x t..

E1 =

p1 x t2

Power register

Energy register

Charge register

ADC,

Temperature, Current,

Voltage

Figure 6-7. Power, Energy and Charge Calculation Scheme

6.3.5 High-Precision Delta-Sigma ADC

The integrated ADC is a high-performance, low-offset, low-drift, delta-sigma ADC designed to support

bidirectional current measurement. The measured inputs are selected through the high-voltage input multiplexer

to the ADC inputs (see Figure 6-6). The ADC architecture enables lower drift measurement across temperature

and consistent offset measurements across common-mode voltage, temperature, and power supply variations. A

low-offset ADC is preferred in current sensing applications to provide a near 0V offset voltage that maximizes the

useful dynamic range of the system.

The INA745x measures the die temperature, current, and bus voltage. An internal temperature measurement is

made before each current measurement. Temperature compensation is then applied to the current measurement

to achieve low drift performance. The MODE bits setting in the ADC_CONFIG register permit selecting modes

to convert only the current or bus voltage to further allow the user to configure the monitoring function to fit

the specific application requirements. After an ADC conversion is complete, the converted values independently

update in the corresponding registers where the values can be read through the digital interface at the time of

conversion end if no averaging is selected.

The conversion times for shunt voltage, bus voltage, and temperature inputs are set independently from 50µs to

4.12ms depending on the values programmed in the ADC_CONFIG register. The value for current is calculated

after both the temperature and shunt voltage measurements are made. The total time to get the current

measurement is the sum of the conversion times for these two parameters. Enabled measurement inputs are

converted sequentially, which means the total time to convert all inputs depends on the conversion time for each

input and the number of inputs enabled. When averaging is used, the intermediate values are subsequently

stored in an averaging accumulator, and the conversion sequence repeats until the number of averages is

reached. After all of the averaging is complete, the final values are updated in the corresponding registers that

can then be read. These values remain in the data output registers until the values are replaced by the next

fully completed conversion results. In this case, reading the data output registers does not affect a conversion in

progress.

The ADC has two conversion modes—continuous and triggered—set by the MODE bits in the ADC_CONFIG

the output registers as described above in an indefinite loop. In triggered-conversion mode, the ADC converts

INA745A, INA745B

SBOSAC3B – JULY 2023 – REVISED AUGUST 2025

www.ti.com

Submit Document Feedback

Product Folder Links: INA745A INA745B

INA745AIRELR датащи(PDF) 16 Page - Texas Instruments

INA745AIRELR 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 48 49 50

датащи скачать

ссылки URL