TPS274160: Inductive load switching with paralleled channels

Lutz Naumann

Part Number: TPS274160
Other Parts Discussed in Thread: TPS272C45

Dear team,

TPS274160 is used with all 4 channel in parallel. for ohmic loads this seems to work fine. However, also inductive loads shall be switched. This seems to have some problem. Goal is to switch an inductive load with 2A 24V => 48VA. Therefore the inductivity would be 1,2H and 12Ohms. Ideally we would also switch at higher temp say 60-70°C. We are observing that TPS274160 can not handle this condition and blows up. What could be the reason? Can the internal TVS diodes not handle the condition or is potential mismatch of the TVS didoes the problem causing a kind of cascaded effect.

Do you have any experience what is possible when switching inductive loads in the paralleled output configuration?

many thanks

Lutz

over 1 year ago

0 Yichi Zhang. over 1 year ago

TI__Genius 16390 points

Hi Lutz,

In this case, 2A and 1.2H is too much inductive energy for our part to handle. The max energy capability is outlined in the plot below.

In this case, I would suggest an external TVS at the output to dissipate the inductive energy.

Please let me know if you have additional questions.

Regards,

Yichi

0 Lutz Naumann over 1 year ago in reply to Yichi Zhang.

TI__Expert 6110 points

Hi Yichi,

many thanks this does make sense. Recalculation for the single channel load the equivalent would be 600mJ @ 500mA if I'm not mistaken. The 500mA is kind of a standard load current in industrial. Do we have this data point by any chance?

kind regards

0 Yichi Zhang. over 1 year ago in reply to Lutz Naumann

TI__Genius 16390 points

Hi Lutz,

We have tested 500mA turn off with 1.15H according to DC-13 test. The energy you specified should be larger than the test we did.

From the plot it seems risky for 600mJ @ 500mA. I would still suggest an external TVS to be safe in this case.

An alternative option is to use TPS272C45. It's a two channel device with better inductive energy dissipation capabilities.

May I know who is the customer and what's the end application?

Regards,

Yichi

0 Lutz Naumann over 1 year ago in reply to Yichi Zhang.

TI__Expert 6110 points

Thanks Yichi,

then I will ask to use external TVS.

Lutz

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TPS274160: Inductive load switching with paralleled channels