MP5470, configuring internal register without MPT

DC-DC Power Converters
1

Hi support,
we’re planning to use MP5470 in our application but we’re a bit confusing regard the I2C programming function.
In order to change the chip configuration prior to start the buck converters, is mandatory to write the MPT memory or it can be done simply writing I2C registers at any startup?

What we want to obtain is the following:

  1. power the board keeping regulator ENABLE low
  2. write internal configuration (to change i.e. SW1 and SW2 to parallel mode) in I2C register without saving it
  3. drive ENABLE high to start converters

Is it possible?

Thank you very much for any suggestion,
Regards.

2

Hi @m.landoni,

MTP is generally used to write to non-volatile memory so that your register settings remain even when the device goes through power cycles. However, you should also be able to write to the I2C registers through volatile memory at startup to make temporary changes that are reset when the part shuts down.

Thank you,
Isabella

3

Hi Isabella,
thank you very much for the quick reply.
Please could you suggest a correct procedure for doing that avoiding incorrect voltage output before the register set?
Thank you,
Regards.

4

You should be able to change the I2C registers by applying a voltage to VIN1 while keeping the enable pin low. Once you have made your changes, you can pull the enable high to enable your output voltages. Are you using external resistors for the output feedback network?