MP6528GR-Z minimum pulse width

Motor Drivers/Sensors
1

Hi,

Hope all is well!

Could it be possible to find out the minimum pulse width that I can get with MP6528GR-Z (assuming that I will use the proper MOSFETs/)? e.g. Can I get pulses close to 1us?

Thank you!
Jones

2

Hello, welcome to the MPS Forums!

Assuming you use the right MOSFETs where the gate charge and on/off times all work with a minimum pulse width to achieve pulses close to 1us, you would need to make sure of the following:

  • The operating switching frequency is set higher which would ensure that your pulse widths are also subsequently 1us short, which for this part is determined by the FETs you have picked. For PWM frequencies over 30kHz (which you definitely will be using given a 1us pulse width, then a shorter dead time would be desired). More details of how this may be configured can be seen on page 14 of the MP6528 datasheet.
  • The load that you are driving would also have an influence on your minimum pulse width. For example, if your load is capacitive, then more time would be needed to both charge and discharge, which would effectively limit your minimum pulse width.

So, I suppose to answer your question in summarized terms, the minimum pulse width would depend on the MOSFETs you choose and the nature of your load but should be achievable.

1 Like
3

Hi Krishan,

Thank you for the support.

Does this mean that having a pure resistive load, a 1us pulse can be achieved? Additionally, could you please provide the maximum PWM frequency of the MP6528GR-Z and its propagation time? We were unable to find the related information in the data sheet.

I appreciate your assistance!

Thank you!

Regards,
Jones

4

Please excuse the massive delay on the response here, the PL who finally got back to me on this subject has relevant information here for what you are asking about:

"Unfortunately, that’s not a simple question. The max PWM frequency depends on the min and max duty cycle as well as the dead time setting.

The minimum dead time setting is around 100nS. And the prop delay is about 40nS. But resistance in the gate signals will require more than 100nS dead time."

In essence, the operating conditions would determine the maximum PWM frequency here.