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Ripple to peak current ratio (Kp)in TOP 267K (Top switch-JX)

Posted by: karthikkalyana… on

On looking into the spreadsheet of PI expert design tool,the following questions came up in my mind

1)In which mode does TOP 267K operate(DCM/CCM).
2)Why there is no option in spreadsheet to define the operating mode of TOP267K
3) How to arrive on the Kp value .

Can anyone help me on the above queries...

Note: I am designing a flyback converter with Optocoupled secondary regulation for a universal input power supply(85-265VAC)

Comments

Submitted by PI-Kenobi on 07/03/2019

1) The mode of operation depends on the KP value. 0https://ac-dc.power.com/sites/default/files/product-docs/an47.pdf) for detailed information regarding the definition and calculation of KP

Submitted by karthikkalyana… on 07/07/2019

Thanks for your reply Kenobi,i have gone through the application note ,still i am confused regarding the operation of TOP267K.
Does it work in DCM/CCM or both?
Can i configure TOP 267K to work in CCM all the time?
Does it dynamically switches between CCM and DCM by itself depending on input voltage and load?
if dynamically switches between CCM and DCM,which Kp formula i should consider for calculation?
Kp=ir/ip or kp=(vor*(1-Dmax)) / (Vmin-Vds)*Dmax

Submitted by PI-Kenobi on 07/08/2019

As you rightly mentioned, the device will switch between CCM and DCM based on the line and load condition. While creating the design using PI Expert, the user has the option to select a KP value which will be observed at full load and the valley of the rectified input voltage. The appropriate formula will be used depending on whether 0.4

Submitted by karthikkalyana… on 07/10/2019

Thanks kenobi,i believe you have not completed your answer.whether 0.4..........then???

Submitted by PI-Kenobi on 07/15/2019

The appropriate formula will be based on whether the design in CCM or DCM