TPS61030: Booster and Buck Converter

Carlos B.

Part Number: TPS61030

Hello ,
I have a main power supply from 8 to 32 volts. A DC/DC converter supplies 4.2 volts. If the main supply fails, the battery must supply the device further. The battery has only 2 to 3 V operating voltage and must boost with a booster the voltage to 4.2 Volt.
Can there be problems when the 2 DC / DC converters work together? Schottky diode separation has too high losses. What can I do?

over 7 years ago

0 Jasper Li over 7 years ago

TI__Mastermind 46905 points

you can refer to the reference design PMP9755
1. Add a schottky diode in parallel with the TPS54540 to prevent current flowing to 8V~32V rail through the MOSFET body diode when there is no voltage in the 8V~32V rail.
2. if both device are enabled, you share set the output voltage of TPS61030 lower than the buck converter to prevent it from operation in normal condition.

0 Carlos B. over 7 years ago in reply to Jasper Li

Prodigy 40 points

Thanks for the solution,

you switch off the power source to the booster?

I had 30 Proto-Pcb with this booster, 2 have broken. Input short-circuited.

Regards

0 Jasper Li over 7 years ago in reply to Carlos B.

TI__Mastermind 46905 points

the damage as you described is normally caused by the layout problem. could you share your layout? or you can refer to the application note "www.ti.com/.../slva773.pdf" to review the layout

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TPS61030: Booster and Buck Converter