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Power management forum

Genius 16285 points
Part Number: LM74701-Q1
Other Parts Discussed in Thread: LM74721-Q1, LM74800-Q1, LM74700-Q1

Hi all

My customer is looking for a high side protection solution (automotive, truck) with these specs:

Nominal voltage: 24V  (16V ... 36V)

Max current: 150A

Reverse polarity protection, TVS-less, they are referring to ISO7637

They did look at several devices, e.g. the LM74701-Q1.

Can you recommend the best fit TI device ?

And do you have an application circuit for these specs ?

Best regards

Ueli

  • Hi Ueli,

    For TVS less, reverse polarity protection and 150A load current LM74721-Q1 would be the right fit. The Integrated VDS clamp feature in this device enables input TVS less system designs for automotive ISO7637 pulse suppression. Also, the integrated boost converter enables low Iq and higher gate drive current (suitable to drive more FETs in parallel for high current applications).

    This device is available for preview in TI.com and expected to RTM by the end of May or early June this year. 

  • Hi Praveen

    Thank you for the quick reply !

    Best regards

    Ueli

  • Hi Praveen

    Below comes a follow on question referring to slyt818.pdf 

    Can you comment ?

    Best regards

    Ueli

    ----------------------------

    “According to the slyt818.pdf document, for TVS-less feature we would require external MOSFETs providing 30-50mV forward drop at full load current, meaning 0.2-0.3mOhm of total Rds,on which is very low…

    What would be the consequence of using higher total Rds,on (for example 1.6mOhm (240mV forward drop)) ? Power dissipation issues ?“

  • Hi Ueli,

    The concept of recommending 30-50mV forward drop at full load current is not related to TVS-less feature. This is related to the Linear Gate control and is recommended for all devices (LM74700-Q1, LM74800-Q1) with this control technique. You can find the logic behind this recommendation in the LM74721-Q1 datasheet section '9.2.2.4 MOSFET Selection: Q1' as shown below.

  • Hi Praveen

    Thank you for the quick reply.

    Best regards

    Ueli