DRV8837: DRV8837 and DRV8832 efficiency issue

Part Number:DRV8837

Hi,

I ran the same scenario for both TI drivers with 3xAA batteries connected to TI DC booster TPS63050

In both cases I ran the eval boards with the same VM of 5V.

On both I choose a 50% duty cycle so motor will run in 2.5V.

Running both till total battery depletion.

DRV8832 ran for 23.5 hours

DRV8837 ran for 17 hours

Am I missing anything here? After all DRV8832 has a higher RDSon + Rsens.

One more issue is about the internal shoot through protection, does it have it?

Thanks,

Tzion