LM5116: LM5116 - Start up Issue

Tool/software:

Dear Sir,

When 12V battery is connected at output and then input is given to converter, IC does not provide the pulses to high side gate. But this problem does not occur with  LM5146.

Input Voltage Range 35-72V

Please find the attached waveform with the below descriptions.

1.       Input Voltage (VIN)                             ->   Yellow, 10V/dev

2.       Output Voltage (O/P V)                     ->   Green, 2V/dev

3.       Boot Capacitor (BST_CAP)                 ->   Pink, 2V/dev

4.       Lower Gate Drive (LO)                        ->   Orange, 2V/dev

5.       Higher Gate Drive (HO)                      ->    Red, 2V/dev

We are looking forward your quick response.

Thanks & regards