Positive and negative output DCDC

Sasaki,

For the Vin: 3.2V to 3.6V Vout: ±40V application, please refer to the Figure.22 in TPS61170 dadaheet . It is just fit for this application.

BR,

Helen

Helen-san,

Thank you for your response.
I checked Fig.22 in TPS61170 datasheet. I think this circuit is non-isolated circuit and transfer connected serial. Is my understanding correct?
Then how can I get negative voltage?

Best Regards,
Kohei Sasaki

Dear Sasaki,

Yes, this circuit is non-isolated.

Please refer to the reference design PMP9770 at the TI website http://www.ti.com/tool/PMP9770?keyMatch=PMP9770&tisearch=Search-EN-Everything , just replace the TPS61085 with TPS61170, you can get both positive and negative output voltage. for the negative voltage, you can use charge-pump doubler(charge pump two times) to get -40V voltage. 

Does the customer hope the +-40V output need to be isolated with the input voltage?

BR,

helen