Is there a way to achieve VOUT = 5V / IOUT = 5A in Buck-Mode with MP4242B?

DC-DC Power Converters
1

Dear MPS FAE support team

About MPQ4242B

Is there a way to achieve VOUT = 5V / IOUT = 5A in Buck-Mode?

1. target specifications; VIN=5～24V VOUT=5V/IOUT=5A

2. Inquiry Details

Now

2-1) PPS_3A_5A Register 22 changed from 3A to 5A and ROM writing was performed, butthe current limit was not changed.

2-2) Please explain why the current cannot be changed and how to change it.

3. Things I tried

３‐1）Conditions under which changes were attempted

BUCKBOOST 5V→5.05V

IOUTLIMIT 3.6A→5A

I2CControleVoutEnabel →Vout Change Based on the VOUT/IOUT_CC Resister Setting

PPS MAXIMUM Current Mode 3A→5A

2

Hi @syamamoto ,

What is your application use with the MPQ4242B? Are you intending to use it for USB application, or something else?

I believe that the MPQ4242B may be limiting the output current due to the standard USB-PD protocols, which limits current to 3A for voltages under 20V. Though, before jumping to that conclusion, are you making sure to use a USB-C cable that can support 5A?

image

You can also try to modify PDO_SET2 register to set all the PDO objects to APDO mode (PPS), so that you can utilize the 5A output.

Last thing to make sure is to not power cycle when writing to volatile memory. Keep the device powered when making register modifications to volatile memory.

Thanks,
Rubas

3

Dear Rubas

Thank you for your reply. I understand the content.

I’m thinking of supplying 5V not as a USB output, but as a power source for a general-purpose microcontroller like a Raspberry Pi.

For reference,

I’ve listed the detailed environment settings and actions taken for this study. Please let me know if there are any mistakes or suggestions for improvement

＊ Writing Procedure

① Load the SPEC file saved with the settings changed

② Verify the parameters.

③ Write to RAM (Volatile Memory) using GO BIT NOT.

④ Write to RAM using GO BIT Resistor: Visually confirm the voltage value change.

⑤ Verify actual operation: Current OK.

⑥ Read RAM.

⑦ Export and verify the parameters.

⑧ Write to ROM(Non Volatile memory).

⑨ Restart the power supply and verify actual operation.

＊ Environment

Evaluation board + EVKT-USBI2C-02

Cable: 5A

Load: Electronic load connected in parallel with a commercially available microcontroller board (for current capacity verification)

＊Also, I have an additional question regarding the MPQ4242B.

The following description is given regarding VREF, but what is the voltage of VREF?

image
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I couldn’t find the VREF voltage in the datasheet.

Thank you

4

Hi @syamamoto ,

Vref changes depending on your output voltage:

image
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Can you try setting the output to 20V and check if 5A is available?

Thanks,
Rubas

5

Hi Rubas

Thank you for the information.

I understand VREF now.

I will continue to try to figure out IOUT=5A.

Best Regards

S,Yamamoto