Hi Team,
My customer is using AT8236, which is a BDC driver with following spec, 4.5A peak current, 3 A continue current, Typical RDSon(HS + LS) is 200mΩ. Customers have found that the AT8236 gets very hot at 3A continuous current. Do you think DRV8251 with 450mΩ is a good P2P alternatives? How does the temperature rise of the DRV8251 perform under the condition of 3A continuous current? Or is there is any other options?
Thanks and best regards,
Hailiang
Hailiang,
The power losses at 3A (considering conduction alone) with the DRV8251 will be at least 4W...(3A x 3A x 0.45). If competition part is really 200mohm, then the losses for AT8236 will be 1/2 that and <2W. 2W should be very manageable which makes me think the board layout is not good for the AT8236. If the board layout is not good, our device will have an even bigger problem on that layout. Please see this figure in the datasheet. Thermal pad (on bottom of device) must be soldered to the PCB and thermal vias (the circles you see) must connect to copper on the ground plane and any other copper on top and bottom of PCB that is GND.
Could they consider a device like the DRV8874 which has a lower Rdson? What is the ambient temperature they are testing in?
Regards,
Ryan
