LM5123-Q1: 12V to 50V@4A design verification

Hi,

I've tried to design boost converter using LM51551 and LM5121 without success and decided to give LM5123 a try. I've used both Webench Power Designer and Power Stage Designer 5 to determine inductor and loop compensation values. I've designed a simple PCB to test the converter, but unfortunately it burned at 200W load, probably due to soldering issues connected with overheating (low side transistor blew up together with the driver). I don't have another driver to test it again (ordered, but not arrived yet), but I've redesigned PCB for better heating management. I've decided to keep crossover frequency as low as possible, therefore I am oscillating around 1 kHz at all load conditions (1 to 4A). Please find schematics and Power Stage Designer files (topology and loop compensation) attached. Inductor in design is PA2248.153NLT. Are you able to cross-check my design?

Regards,

Bart

lm5123_sch.pdf

LOOP_CALCULATOR
12
50
4
15
8
164
10
164
10
240
2
10
1
3
1
1.2
1200
2
10
60
3
0.1
1
0.2
1
4700
24000
150
1000
0
1
2200
22

BOOST
10
26
50
4
240
0.7
50
15