Other Parts Discussed in Thread: TPS2491
Hi, We are currently redesigning a Hot Swap Controller with LM5069-2. The old Hot Swap Controller was TPS2491. We are not changing the MOSFET. I was using the design tools of LM5069 and TPS2491 for comparing.
I have few queries.
1. Even though we are using the same MOSFET, why is the recommended slew rate for TPS2491 and LM5069 different?
2. I have observed that in our design with TPS2491, we have exceeded the slew rate by a lot but the SOA margin is 1.5 which is good. I have observed that with increasing slew rate, the SOA margin is also increasing. How did the recommended max slew rate value is arrived, what happens if we exceed it?
3. For the LM5069 design, the recommended max slew rate is 4V/ms. When I keep the SS capacitor value as 4, the Start-up FET Power graph shows that at the starting, the power dissipation is around 28W. But if I keep the power limit as 17W, will it go into power limit mode and will it have any impact on soft start?
0447.TPS249x_8x_Design_Calculator_REV_B.xlsx1581.LM5069_Design_Calculator_REV_C.xlsx
I have attached the design files.