LM73605: Use LM73605 to build buck-boost inverter

Sulyn ZHANG

Part Number: LM73605

Hi Team,

My customer is seeking for solution to realize, 12V input and -5V output with 3A load ability. I recommended our LM73605 to working as buck-boost inverter to realize this. I use our TINA to simulated and would you pls help check if my below schematic works for this requirement? Thanks a lot!

LM73605 12V to -5V.TSC

Below is the schematic that I recommend customer to use, inductor is different with TINA simulation file:

From the simulation, the function is ok, can you help double check the schematic. BTW, if customer want to use the Enable and PGOOD, any suggestions or useful guidance for this case, thanks a lot!

Best regards,

Sulyn

over 5 years ago

0 Orlando Murray over 5 years ago

TI__Mastermind 22299 points

Hi Sulyn,
I've forwarded your question to a product expert for review!
They will get back to you in a few days with suggestions.
-Orlando

0 Sulyn ZHANG over 5 years ago in reply to Orlando Murray

TI__Expert 8700 points

Hi Orlando,

Thanks for the feedback back, will wait for expert's suggestion and hope we can give customer available solution to win this case, thanks a lot!

Best regards,

Sulyn

0 Katelyn Wiggenhorn over 5 years ago in reply to Sulyn ZHANG

TI__Genius 11040 points

Hello Sulyn,

Can you confirm if the schematic that the customer will use and you want to be reviewed is the TINA file or the image that you shared?

I reran the simulation with the 8 uH inductor, and I agree that this looks good.

In regards to the EN pin, this can be tied high for the device to turn on with the input voltage crossing the UVLO. If you want increased control over the turn on point, you can use a voltage divider to vary the turn on point based on the EN UVLO.

In regards to the PGOOD pin, you need to tie this pin high with a pull up resistor ( < 20V). Then, the PGOOD pin can be used as an indicator of when the device is in and out of regulation.

Thank you,
Katelyn

0 Sulyn ZHANG over 5 years ago in reply to Katelyn Wiggenhorn

TI__Expert 8700 points

Hi Katelyn

Thanks for the support, you can use the image one with the parameters, for the TINA, it's just for simulation purpose.

Best regards,

Sulyn

0 Katelyn Wiggenhorn over 5 years ago in reply to Sulyn ZHANG

TI__Genius 11040 points

Hi Sulyn,

Thank you for clarifying. Then this looks good to me. Please let me know if you have any additional questions.

Best Regards,
Katelyn

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LM73605: Use LM73605 to build buck-boost inverter