LM63615-Q1: Does this design will work for converting -15v from +15v.

Hi Ratnesh,

Review comments for your design:

1. Connect C1 to -Vout and not GND. 

2. Consider adding a Feedforward capacitor for better loop performance. (100pF can be a good starting point). 

3. Ensure C5 and C6 are high quality ceramic caps (Eg: X7R) for good thermal stability. 

4. Refer to these app notes for caveats of using Buck Converters for IBB applications (https://www.ti.com/lit/pdf/snva856; https://www.ti.com/lit/pdf/slyt286). 

Thanks,

Best Regards,

Taru

Hi Ratnesh,

ratnesh maggar said:

1. As per your comment, C1 should be connected to –Vout instead of GND. However, in the application note (Inverting Buck-Boost Application for the LM63615-Q1), it is shown connected to GND. Could you please check and suggest the correct connection?

You can keep the C1 connected to GND. 

ratnesh maggar said:

• Could you also confirm whether, with the selected components, the output voltage will be exactly –15 V without any significant drop?

You should get -15V as nominal output voltage (there will be tolerances based on the feedback resistor's accuracies and the feedback reference voltage accuracy). However, with typ specs - you should get a -15V output. 

ratnesh maggar said:

1. If you are available, I would also like your support in resolving another query regarding the LMR33610 and LMR33640.  (Y/N).

You can post your query on the e2e forum and it would be supported by the right apps engineer. 

Thanks,

Best Regards,

Taru

Thanks,

Best Regards,

Taru

Yes,

As you had already pointed out from the app note - the Cin capacitor (between Vin and GND) can be added to the input for better transient performance. 

Thanks,

Best Regards,

Taru

Yes,

As you had already pointed out from the app note - the Cin capacitor (between Vin and GND) can be added to the input for better transient performance. 

Thanks,

Best Regards,

Taru