Design review-ADP5070-5V to P&N12V

Hi

May I know what is the output current for both the positive and negative 12V output?

Just to confirm, the switching frequency used in this design is 2.4MHz. Correct me if I am wrong.

Thanks

Regards,

Dave

Hi Dave,

Max output current is 200mA per channel for positive and negative 12V output.

And The switching frequency we designed is 2.4MHz.

Best Regards!

Xing

Hello Xing,

The positive rail can accommodate the 200mA output load but it seems that the negative rail will enter current limit protection. At 200mA output load, the average inductor current for the inverting channel will be greater than the current limit of the switch, which is 0.6A, and will go higher if we add the inductor ripple current.  Please refer to the equation below for verification.

I suggest you use the ADP5071 which has a higher current limit for the inverting channel. Also, you can use the Excel Design Tool for convenience. Below is the download link of the design tool for ADP5070/ADP5071.

http://download.analog.com/PMP/ADP507x_Designer.zip

Let me know what you think. Thanks

Best Regards,

Dave

Hello Xing,

The positive rail can accommodate the 200mA output load but it seems that the negative rail will enter current limit protection. At 200mA output load, the average inductor current for the inverting channel will be greater than the current limit of the switch, which is 0.6A, and will go higher if we add the inductor ripple current.  Please refer to the equation below for verification.

I suggest you use the ADP5071 which has a higher current limit for the inverting channel. Also, you can use the Excel Design Tool for convenience. Below is the download link of the design tool for ADP5070/ADP5071.

http://download.analog.com/PMP/ADP507x_Designer.zip

Let me know what you think. Thanks

Best Regards,

Dave