BQ756506-Q1: Current Measurement Accuaracy

stefan wolter

Prodigy 30 points

Part Number: BQ756506-Q1

Hello TI Team,

A question about the DS parameter "VACC_MAIN_CS" it says ADC accuracy for current sense is 1.1mV.

If I use a 100uOhm shunt, means the accuracy is 10A, is that correct?

How can I calculate the total accuracy of the current measurement channel, with aging and temperature

Thanks

Stefan

over 1 year ago

0 Michelle Williams over 1 year ago

TI__Prodigy 540 points

Hi Stefan,

You can calculate the accuracy of the CS ADC by using the CS ADC datasheet values (pg 12-13) and the equation below:

Absolute accuracy = +/- [(Input_Voltage x %ofReading) + (Voltage_Range x Offset) + System_Noise +Temperature_Drift]

You can also use the link for further information on calculating the offset: https://www.ni.com/en/support/documentation/supplemental/18/calculating-absolute-accuracy-or-system-accuracy.html

Just note that you will also need to consider the tolerances of any other components used in the circuit, such as resistors, etc., to find the overall system accuracy.

Sincerely,

Michelle W.

Power management

Power management forum

BQ756506-Q1: Current Measurement Accuaracy