Other Parts Discussed in Thread: DRV8243S-Q1LEVM, DRV8243-Q1, DRV8873-Q1
I've recently tested the "DRV8243S-Q1LEVM" evaluation board. An important point for me was the current measurement accuracy.
I got better current measurement accuracy than what is in the datasheet.
So I wanted to ask you why is that?
According to the data sheet, it comes with:
I did my measurements as follows:
I have set the following settings on the GUI: S_ITRIP: 2.64V RIPROPI: 1.5kΩ Slew Rate: 43V/usec TOFF: 30 usec
I soldered the RIPROPI resistor 1.2 kΩ.
As a load I used resistive load. I examined the current measurement accuracy as follows:
- Measured the voltage at the IPROPI pin (mean value recorded on the scope - UIPROPI in tabel)
- Measured the current through the load with an ammeter (KEYSIGHT34450A)
- IIPROPI calculated according to the formula from the data sheet
- AIPROPI = 3075, RIPROPI = 1.2kΩ
- Compare the calculated IIPROPI current with the measured current (with KEYSIGHT34450A).
- From this the measurement accuracy is determined
Here are my values:
What's the difference? Can you please tell me what the current measurement accuracy depends on and why it is so inaccurate with smaller currents?
My desired current measurement range is up to 6 A.
Thanks and Regards