Hello,
Figure 13 of the data sheet (SNVSA42B) shows an input transition voltage from PWM to PFM in AUTO mode at no load, but what's the variation (Min and Max) of this threshold?
Best regards,
Shinichi Yokota
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Hello,
Figure 13 of the data sheet (SNVSA42B) shows an input transition voltage from PWM to PFM in AUTO mode at no load, but what's the variation (Min and Max) of this threshold?
Best regards,
Shinichi Yokota
Yokota-san,
I will look for this data. I will reply in a day or two.
-Sam
Yokota-san,
I'm sorry to say we do not have this data. We only have one characteristic curve. We do not have statistical data for min/max.
-Sam
Sam-san,
Is it possible to give us rough estimation of the Max/Min values from design files such as schematic? If the VIN threshold is determined by a resistor divider, for example, an error of the resistance ratio would have a major impact on the VIN threshold variation. Rough number is OK for us. Could you look into this again?
Please let me ask one more question. If the input voltage drops in AUTO mode when a device is operating in PFM, will the device switch back to PWM again? If yes, what's the input threshold?
Best regards,
Shinichi Yokota
Shinichi-san,
I am checking again to see if we have an approximation.
To answer your second question, the datasheet states, "Also, once the regulator switches to PFM, at light load, it will remain in that mode if the input voltage is reduced."
-Sam
Shinichi-san,
Our estimate is up to 10% above the value given but this is not guaranteed.
-Sam
Sam-san,
Do you mean a typical value (on Figure 13) ±10%? Or, a typical value +10%?
How about a question about a threshold for falling VIN?
Best regards,
Shinichi Yokota
Shinichi-san,
I mean typical value +10%.
Once in PFM, the IC stays in PFM if VIN falls.
-Sam