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 4, 2021 3:08 PM in reply to alex.bukvin@teson.com.ru

    Hi Alexander, 

    It would be good for us to know which of the three regulators is running in PSM mode in the applications condition where the interference was seen. You can use the scope and probe on each of the output of the regulator. Then, add a dummy load of few mA's (increasing from uA to mA range) on the regulator operating in PSM mode for it to go  into DCM. You can double check on the final output if there still interference.

    Thanks and regards, 

    Jefferson 

  • +1
    •  Analog Employees 
    on Apr 4, 2021 3:21 PM in reply to jeco

    Hi Alexander,

    Can you please give me some information about the application and the operating conditions like VIN, VOUT voltages and loads, what transformer was used.

    If you can share the schematic, it would be great; for my reference.  You can send it in my email, Jefferson.Eco@analog.com. 

    Thanks and regards, 

    Jefferson