1. I have designed a circuit using TI's bq24650. Schemtaic & gerbers are attached. (Part of both are removed, only I have shown is high current path & mosfet).
2. I have to operate circuit at 10A. Problem is Mosfet gets too hot at 5A or above even after 2 min of operation. Also Diode D1 PDS1040 gets heated up, but they are not very hot.
3. Actual circuit has only one mosfet but it was rated for lesser current. So I have used 2 in parallel in my circuit. What could be issue with the circuit, are track length too short. I have removed solder msak layer from high current path as in gerbers you can check. Also while soldering I have placed a thick solder on these exposed tracks. Mosfet has high current rating as you can check in mosfet datasheet.
Is the inductor saturating?
Does the BQ24650 have enough gate drive that the mosfets are switching hard and not spending time in the linear region?
I am not expert but if the gate didn't get enough voltage to switch fully on I think it would be a problem, because the Rds on state wouldn't reach its minimum which will cause the transistor to get hotter at higher current
No, inductor is not saturating. It is rated for 32A sat.
Max input voltage is 21V.
Are these mosfet capabple of handle this current or some thing wrong in designing layout around these mosfets
Hmm. Assuming the mosfets are being driven cleanly, looking at the gerbers, you probably want better heat conductivity from the drain pads of those mosfets. As it is, you have the thermal relief (which makes it easier to hand solder). You probably want to eliminate that and have some thermal vias to copper on the other side. This kind of package is heavily reliant on those drain connections for thermal conductivity.
A look at the waveform between the S1/D2 node and ground on a scope might clarify whether the mosfets are switching as expected -- don't forget that the connections need to be really short, including the ground lead.