Intel Gatkek CYPD5235 current sense issue

[Augustine_Yeh]

Hi Cypress

We use cc communication equipment to request 20V/4.25A power supply. We verify the output voltage and current through the electronic loader. The test result is only 20V/4A (250mA less). But we change 0.01 current sense resister to 0.005, It can output power to 20V/4.25A .Please tell us how to debug the problem, thank you ! !

[Abhilash_P]

Hi,

  From the mentioned details, we can conclude 2 things,

1. There might be an extra loading effect on the output current from the electronic load which is used for measuring the output.
2. Since Rsense is in the provider path, it might be contributing to the drop in load current.

       (Rsense is a small value, eventually we can rule out this possibility). (Even if there was a drop across 0.01 Rsense, there might be negligible change in the output current (9mA) and not as high as 250mA.)

But we cannot be completely sure of the above mentioned possibilities without further testing for other conditions.

Can you please check if you are encountering the same problem (delta change in output current)with other PDO's as well?

And also please cross check with other designs to make sure that the electronic load is working correctly and not contributing to an extra loading effect

If it is possible, please attach a brief block diagram of how you are trying to measure the output current and voltage from the electronic load.

Please revert back to me with above mentioned requests so that it would be easy for me to debug the issue.

Regards

Abhilash P

[Augustine_Yeh]

1.Can you please check if you are encountering the same problem (delta change in output current)with other PDO's as well?

And also please cross check with other designs to make sure that the electronic load is working correctly and not contributing to an extra loading effect ==>We have compare with intel demo board , It can work about 20V/4.81A , But our DUT is only 20V/4.16A

If it is possible, please attach a brief block diagram of how you are trying to measure the output current and voltage from the electronic load.

==> Attached file is test environment for you reference , Thank !!

[Abhilash_P · Accepted solution]

Hi,

   I suggest you to please measure the output voltage and current through an electronic Digital multimeter to obtain accurate values.

And while connecting the current measuring meter, place it close to the ground as it would reduce the effect of stray capacitance while measuring (connect the current meter on the ground terminal of the load). If you are measuring a small current value, it is desired to place it near to the DUT.

And please try measuring the output voltage across the DUT and not on the tester as there would be some loading effect along the cable and in the tester

Measuring output current through an electronic load is usually not preferred.

Please let me know if you are still facing the issue.

Regards

Abhilash P