TPS560430: TPS560430 for negative voltage power supply

Hello

Please see the attached application note for help with designing an IBB.

Note that you can get an EVM and configure as shown in the application note

and test this design in your application.

Thanks

1212.snva856a.pdf

Hi Frank,

Thanks for answer and application note.

I also found some information and built a simulation circuit，but I have two question about the simulation.



1、Why the output voltage start with -5 V?
2、Why the output voltage ripple is so large even use 22uF cap?

Hello

The initial conditions on your output capacitors is 5V.  You can change to 2.5V or zero to see the start-up.

An IBB will always have higher ripple than a buck because of the pulse currents in the output capacitor.

Your target of 5mV is rather small.  You can try increasing the output capacitance or you will need an output filter.

I will assign your post to the engineer in charge of E2E for August.

Thanks

Hi frank,

Thanks for answer. So can I know who will help me deal with this problem?

Hi Kevin,

Did you manage to implement the changes that Frank recommended? How do the results change?

Regards,

Richard

Hi Richard,

I applied for the TPS560430 Demo board and modified the circuit to achieve -2.5V output. However, the output ripple is very large, and adding a 100uF capacitor cannot reduce the ripple.

And I see the application noted that the ripple is 20mv,  Can it be reduced to 5mv?

If the ripple cannot be reduced, do you have any other materials you can recommend to me?
Customer requirement : the input is 4.5-9V, the output is -2.5V, and the output ripple is 5mv.