TPSM63606: Clarification to have negative output voltage

ArTzy

Part Number: TPSM63606
Other Parts Discussed in Thread: TPSM53604

Hi Experts,

Good day.

If I want to design a positive input to provide negative output (-15V) using TPSM63606, is it possible?

I could see that PGND and AGND from its typical example of datasheet both have different ground reference; are they connected internally? If not, would it be possible to make the Vout as reference side of the overall system and make reading to AGND pins as ouput (-15V)?

Thank you.

Regards,
Archie A.

over 2 years ago

0 ArTzy over 2 years ago

TI__Genius 13959 points

I hope it can:
https://e2e.ti.com/blogs_/b/powerhouse/posts/laying-out-an-inverting-buck-boost-converter-for-success

Regards,
Archie A.

0 Jimmy Hua over 2 years ago in reply to ArTzy

TI__Mastermind 47060 points

Hi Archie,

Please refer to the following app note for more details on IBB design consideration: https://www.ti.com/lit/an/snva856a/snva856a.pdf

Also please refer to this FAQ https://e2e.ti.com/support/power-management-group/power-management/f/power-management-forum/997124/faq-can-this-buck-regulator-be-used-in-for-an-ibb-application

The two considerations are maximum input voltage and inductor current.

Here is an example of the TPSM53604 power module converted for IBB application https://www.ti.com/lit/an/snva897/snva897.pdf

Regards,

Jimmy

0 ArTzy over 2 years ago in reply to Jimmy Hua

TI__Genius 13959 points

Hi Jim,

Thanks for the relevant information you shared.

I appreciate it more if you would answer and confirm my question above: Does PGND pin connected internally with AGND?

Thank you.

Regards,
Archie A.

+1 Jimmy Hua over 2 years ago in reply to ArTzy

TI__Mastermind 47060 points

Hi Archie,

Looking at the Table 6-1 Pin function of this device, it doesn't look like AGND is internally tied to PGND. Because of this the pin description details the followig "These pins must be connected to PGND".

For IBB application, the system return is VOUT and the negative output voltage is AGND/PGND. You would connect your input supply between the VIN pin and VOUT pin. Your negative output voltage rail will be between the AGND/PGND pin and VOUT pin.

Regards,

Jimmy

0 Timothy Hegarty over 2 years ago in reply to ArTzy

TI__Mastermind 49317 points

Hi Archie,

There is an IBB application example (-12V, -2.5A) in the datasheet that you can review. Let me know if you have a specific Vout, Iout requirement. As shown in Figure 9-13, the output current capability in IBB depends on Vin-min (as the inductor current is Iin + |Iout|).

Regards,

Tim

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TPSM63606: Clarification to have negative output voltage