Part Number:LM5060
Hi,
I used LM5060 to implement protection circuit for OV, UV, OC & reverse polarity protection on BLDC motor PVDD. I used DRV8323 for driving BLDC motor. PVDD is 24V.
As a reference for protection circuit, I have taken fig. 39 (Application with Reverse Polarity Protection with Diodes for OUT Pin Protection). I also have a provision of turn-On delay capacitor (DNP) mentioned in Fig. 28.
I connected two 390uF, 50V bulk capacitors on PVDD near H-bridges.
My concerns are:
1. Druing testing i observed that MOSFET Q1 (in fig. 39) getting damaged. Gate and drain is getting shorted. MOSFET part that i used is IRFB7440PBF. I want to know the probable reason behind the failure and update design. Please suggest me.
2. Also as mentioned in section 8.2.2, D5 & D7 are only necessary if the output load is highly capacitive.In our design two 390uF is used as bulk cap and also motor is having phase inductance of 131uH. I want to know what load shall be considered as highly capacitive? If two 390uF capacitor is not high then shall i remove it from board?
3. If the load capacitance (390uF + 390uF) is large, then should i have to connect current limiting resistor Ro as mentioned in section 8.2.1.2.9 ?
Regards,
Amit