ADP1031-2 working in PSM mode

In our product ADP1031 sometimes switches to Power Saving Mode PSM (with skipping pulses). In this case, everything works, but there is an interference at a frequency of ~7 kHz (Fsync = 512kHz/72), which falls into the band of the measuring chain of the product. This interference degrades the parameters of our device to unacceptable levels. How can we avoid the swithing ADP1031 to PSM mode?

Best Regards,

Alexander

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  • 0
    •  Analog Employees 
    on Apr 1, 2021 2:45 PM

    Hi Alexander, 

    The ADP1031 automatically switch to PSM mode for light load conditions for all three regulators. PSM is inherent to the ADP103x and this mode cannot be turned off but to prevent the part going into PSM mode, a solution is to add a dummy load of few mA's for the part to operate at DCM. This will add a power dissipation but this will prevent the low frequency switching that cause the interference to the band of interest. 

    Best regards, 

    Jefferson 

Reply
  • 0
    •  Analog Employees 
    on Apr 1, 2021 2:45 PM

    Hi Alexander, 

    The ADP1031 automatically switch to PSM mode for light load conditions for all three regulators. PSM is inherent to the ADP103x and this mode cannot be turned off but to prevent the part going into PSM mode, a solution is to add a dummy load of few mA's for the part to operate at DCM. This will add a power dissipation but this will prevent the low frequency switching that cause the interference to the band of interest. 

    Best regards, 

    Jefferson 

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