INA780B datasheet(11/42 Pages) TI1

11 / 42 page

IN+

VBUS

MUX digital

Control

Bus Voltage

Shunt Voltage

Temperature

ADC_IN+

ADC_IN-

To ADC Input

Integrated

Shunt

TEMP

Temperature

Sensor

IN+

SH+

Figure 7-3. High-Voltage Input Multiplexer

7.3.4 Internal Measurement and Calculation Engine

The current and charge are calculated from the voltage drop measured across the internal resistive element,

while the power and energy are calculated after a bus voltage measurement. Power and energy are calculated

based on the previous current calculation and the latest bus voltage measurement.

The current, voltage, and temperature values are immediate results when the number of averages is set to 1

(see Figure 7-4). 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 their 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 they

can then be read.

The energy and charge values are accumulated for each conversion cycle. Therefore the INA780x 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 7-4. Power, Energy and Charge Calculation Scheme

7.3.5 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 7-3). 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 0 V offset voltage that maximizes

the useful dynamic range of the system.

www.ti.com

INA780A, INA780B

SBOSAB6 – JULY 2023

Submit Document Feedback

Product Folder Links: INA780A INA780B

INA780B Datasheet(PDF) 11 Page - Texas Instruments

INA780B Datasheet(HTML) 11 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

Datasheet Download

Link URL