TPS730: The inrush current of TPS730

takahiko yokota

Mastermind 7135 points

Part Number: TPS730

My customer evaluate TPS73033.

However the inrush current is over 200mA.

Are there the provision about inrush current?

Best regards,

Yokota

over 8 years ago

0 Ryan Eslinger over 8 years ago

TI__Guru 55940 points

Yokota-san,

At startup the output capacitors are discharged; therefore, when the LDO is first enabled, high current (inrush current) flows through the LDO to charge the capacitors. This inrush current is normal and is not controlled until current limit circuitry detects the over current and engages.

Please note that current limit for TPS730 is higher than 200 mA.

Very Respectfully,
Ryan

0 takahiko yokota over 8 years ago in reply to Ryan Eslinger

Mastermind 7135 points

Hi Ryan-san

Thank you for the reply.

The inrush current is max 2A in customer's evaluation result.

Is TPS730 acceptable this inrush current?

Best regards,

Yokota

0 Ryan Eslinger over 8 years ago in reply to takahiko yokota

TI__Guru 55940 points

Yokota-san,

This is rather high inrush; however, as it should only be for a very brief period of time before the current limit engages, there will not be much heat generated. If you are concerned, you can move some of the output capacitance to the input so long as you still have the minimum required capacitance on the output and/or place a current limiting resistor in series before the LDO.

Very Respectfully,
Ryan

0 takahiko yokota over 8 years ago in reply to Ryan Eslinger

Mastermind 7135 points

Hi Ryan-san

Thank you for the answer.

Let me confirm you about it just in case.

If there are much heat generated, is TPS730 acceptable 2A inrush current?

Best regards.

Yokota

0 Ryan Eslinger over 8 years ago in reply to takahiko yokota

TI__Guru 55940 points

Yokota-san,

Inrush current of 2 A is acceptable for TPS730.

Very Respectfully,
Ryan

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TPS730: The inrush current of TPS730