MCT8315A: Not using internal BUCK/LDO Regulator

Hello team,

Can anyone answer my question?

Best Regards,
Kei Kuwahara

Hi kei Kuwahara,

For Q1: No need to use it Buck, GD_CONFIG2 there is BUCK_PS_DIS option we can enable buck power sequence.

Q2: Short SW_BK and FB_BK to use LDO. You can refer to GD_CONFIG2 to set the buck voltage if you are using Buck.

Thanks and Best Regards,

Venkatadri S

Hello Venkatadri-san,

Thank you for your answer.

Venkatadri Shantaram84961 said:

Q2: Short SW_BK and FB_BK to use LDO. You can refer to GD_CONFIG2 to set the buck voltage if you are using Buck.

If customer is not using this BUCK, then can they just leave SW_BK and FB_BK open?
Because when they short SW_BK and FB_BK, there were more than 1A current flowing through.

Best Regards,
Kei Kuwahara

Hello Venkatadri-san,

Forget about the previous questions. I have new questions.

Q1:

Is Buck in Resistor mode = LDO operation? Because I have never seen Buck switching Regulator without Inductor.

Q2:

On the MCT8315EVM, it is configured in Buck in resistor mode and CBK = 22uF is used.
If this is LDO mode, then can I use smaller capacitor because there is no external load connected.
I think 22uF for LDO is quite big value.

Best Regards,
Kei Kuwahara

Hello Venkatadri-san,

Thank you for the instruction of using the LDO mode!

Do I need any external capacitor in schematic below, if I want to use the LDO mode?

Best Regards,
Kei Kuwahara

Hi Venkatadri-san,

Thank you for the confirmation!

I have tested in the lab, and it works!

Best Regards,
Kei Kuwahara