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LM3243: PWM frequency range

Joyce Li
Intellectual 2170 points
Part Number: LM3243

Hi Dear expert,

My customer wants to know in heavy load, light load, PWM and PFM mode and spread spectrum mode, what is the SW frequency changing range?

Can you please help on it?

thanks very much!

Joyce

  • 0
    TI__Mastermind 34535 points

    Hi,

    I have notified our expert regarding this issue. Please expect a response by Tuesday July 3rd.

    Regards,

    Shinya

  • 0
    TI__Expert 6330 points

    Hi Joyce,

    The SW frequency will vary when operating in PFM based on the load, output voltage, and input voltage. As stated in the datasheet, the PFM minimum frequency is dependent upon these factors.

    As the load gets larger, the PFM frequency increases, which can get into the 1 MHz range. 

    In PWM mode, the SW frequency remains ~2.7 MHz. The SW should follow the internal oscillator frequency which can be found in the Fosc spec in the datasheet. 

    The device does have spread spectrum mode, it only operates in PFM and PWM.

    Regards,

    Aaron