TPS5430 Thermal Shutdown

Brandon Johnson2

Other Parts Discussed in Thread: TPS5430

To whom it may concern,

I am using a TPS5430 for a 5V supply to another chip and I'm having some issues. My supply is 32V and the chip has no problem regulating 5V unloaded. When I put the expected load on the output (600mA) the chip shuts down after a couple of seconds. I have a reinforced ground plane on my pcb on top an bottom with vias under the chip so the thermal pad can connect to it but it wont regulate under load.

Why are these chips rated for 3A but shut off after 600mA. If anyone has any ideas on how to heat sink it better let me know because I've run out of ideas.

over 12 years ago

0 Anthony F over 12 years ago

TI__Mastermind 35165 points

Hi Brandon,

It sounds like something else is happening because the TPS5430 should not go into thermal shutdown so easily. Can you please share your schematic?

Best Regards,
Anthony

0 Brandon Johnson2 over 12 years ago in reply to Anthony F

Prodigy 90 points

This is my schematic in eagle. I made a quick solution last night by just having another chip step it down to 20 and distribute the power across two chips but I still wonder why it shut off so quickly.

0 Anthony F over 12 years ago in reply to Brandon Johnson2

TI__Mastermind 35165 points

It is possible the control loop is going unstable. The TPS5430 is internally compensated, so the selection of the output inductor and capacitor are important to ensure the control loop is stable. Some guidelines are given on page 14 of the datasheet and C2 may need to be increased.

Can you share the part number for C2?

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TPS5430 Thermal Shutdown