TPS62205: TPS62205 PFM Mode

Yang Wu

Part Number: TPS62205

Hi Team,

I get a question about TPS62205's PFM mode.

Datasheet page 9 says [Two conditions allow the converter to enter the power save mode operation]. one is DCM and another is peak detection.

Does both conditions(DCM & peak) need to be satisfied then controller goes to PFM? or either DCM or peak can allow it go to PFM?

thanks a lot.

Best regards,

Yang

over 4 years ago

0 Yang Wu over 4 years ago

TI__Intellectual 2840 points

Hi Team,

+ 1 more question:

Datasheet says [The N-channel rectifier is turned on and the inductor current ramps down. As the inductor current approaches

zero, the N-channel rectifier is turned off and the P-channel switch is turned on again, starting the next pulse.] in page 10.

Does it means that the switching frequency varies and converter works in Boundary conduction mode when it's in power save mode? It looks like a constant on time operation for a fixed Vin & Vout.

thanks a lot.

Best regards,

Yang

0 Alfonso Furio over 4 years ago in reply to Yang Wu

TI__Expert 3645 points

Hello,

to enter in PFM is sufficient one of the two conditions. About your first question yes, the device is in BCM and the freq. is varying and the ton is defined by the peak current.

0 Yang Wu over 4 years ago in reply to Alfonso Furio

TI__Intellectual 2840 points

Hi Alfonso,

Thanks for your help.

Best regards,

Yang

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TPS62205: TPS62205 PFM Mode