TPS1641: About TVS diodes and Schottky diodes

R.Fukunaga

Expert 1565 points

Part Number: TPS1641

Tool/software:

Hi all,

I would like to know about the placement of TVS and Schottky diodes.

Figure 9-10 shows D1: TVS diode and D2: Schottky diode.

1) Is it okay to use D2 as TVS diode? Are there any concerns?

2) Is it okay to place D1, D2 outside Cin, Cout?

Best Regards,

Ryusuke

6 months ago

0 Kunal Goel 6 months ago

TI__Guru 63075 points

Hi Fukunga,

1. Using schottky as TVS might not be effective as both are designed for different purposes.

2. Yes.

Regards

Kunal Goel

0 R.Fukunaga 6 months ago in reply to Kunal Goel

Expert 1565 points

Hi Kunal,

What is the purpose of using TVS and Schottky diodes? I would like to know the reason why D2 is a Schottky diode.

If possible, could you tell me the expected phenomenon when D2 is a TVS diode?

I would like to use TVS diode for Vout to protect outside the product.

Best Regards,

Ryusuke

0 Kunal Goel 6 months ago in reply to R.Fukunaga

TI__Guru 63075 points

TVS is used for suppressing large positive transient transient on VIN pin to prevent VIN goin above +ve abs max rating.

Schottky is used for clamping -ve VOUT transients to keep device within -ve VOUT abs max. Schottky are more effective as they have low VF at even higher current levels . But TVS also can help at output side.

Regards

Kunal Goel

0 R.Fukunaga 6 months ago in reply to Kunal Goel

Expert 1565 points

My understanding is as follows. Is this correct?

Voltage above the absolute maximum rating is protected by a TVS diode on the input side.

Voltage below the absolute maximum rating is protected by a Schottky diode on the output side.

Best Regards,

Ryusuke

+1 Kunal Goel 6 months ago in reply to R.Fukunaga

TI__Guru 63075 points

Yes. Correct.

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TPS1641: About TVS diodes and Schottky diodes