TLV62569: Question about TLV62569 SW pin negative current capability

Jacky Wang(QD)

Part Number: TLV62569

Hi Team,

Our customer wants to know if the TLV62569 SW pin has the negative current capability to handle some reverse current in some cases, can you help to check how much negative current can be allowed?

Thanks.

over 4 years ago

0 Farheen over 4 years ago

TI__Mastermind 20690 points

Hi Jacky,

Which negative current you are talking about? From ground to SW node or SW to input? Can you elaborate little bit?

Best Regards,

Farheen

0 Jacky Wang(QD) over 4 years ago in reply to Farheen

TI__Genius 11580 points

Hi Farheen,

I mean the low side MOSFET negative current from load to inductor->low side MOSFET->to ground, in customer's board, they can observe about -300mA~-400mA during some use cases, not sure it is allowed by our device or not.

Thanks.

0 Farheen over 4 years ago in reply to Jacky Wang(QD)

TI__Mastermind 20690 points

Hi Jacky,

As it is non-A version. When current reaches zero, device should enter into Power Save Mode (PSM) mode. Can you pleas show me the waveforms where it is hitting this 300-400mA current peak? and for SW node waveforms, location of ground is very important. Can you share you measurement technique that how you are measuring it?

Thanks and Best Regards,

Farheen

0 Jacky Wang(QD) over 4 years ago in reply to Farheen

TI__Genius 11580 points

Hi Farheen,

Please refer to below waveform we measured, please help to check if we have any specifications about this negative current handling. Thanks.

0 Farheen over 4 years ago in reply to Jacky Wang(QD)

TI__Mastermind 20690 points

Hi Jacky,

How you are measuring your SW node voltage if it is possible to tell?

Best Regards,

Farheen

0 Jacky Wang(QD) over 4 years ago in reply to Farheen

TI__Genius 11580 points

Hi Farheen,

We suggested customer to measure the SW voltage using probe grounding spring to minimum ground loop. Can you help to check the current spec for low side MOSFET capability to negative as I shown in the picture? Thanks a lot!

0 Farheen over 4 years ago in reply to Jacky Wang(QD)

TI__Mastermind 20690 points

Hi Jacky,

We do not have any available validation data about this negative spec for LS MOSFET. As I have said earlier, this device has zero current detection, after that device goes/should go into PSM mode. What I see in your shared waveforms is similar to what we have in our datasheet which is normal and intended behavior. You see a tiny delay after it hits zero current and before the disabling of power stage.

Thanks and Best Regards,

Farheen

0 Farheen over 4 years ago in reply to Farheen

TI__Mastermind 20690 points

Hi Jacky,

Do you have any further question related to this thread?

Thanks and Best Regards,

Farheen

0 Farheen over 4 years ago in reply to Farheen

TI__Mastermind 20690 points

Hi Jacky,

I am closing this thread. If you have any more question, feel free to open it by commenting below.

Best Regards,

Farheen

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TLV62569: Question about TLV62569 SW pin negative current capability