Boost converter TPS40210 problem please help....!!!!

[manjunath]

Hi, i have design a voltage booster circuit using TI web bench(circuit is in attachment) using TPS40210 IC and its working fine but when i try to interface my booster circuit with application circuit (Transformer circuit shown in attachment) the 48v voltage drop to input voltage of 20V. i am not getting where the problem is in please can anyone help me.

[manjunath]

Transformer circuit is in this circuit....!!!!

[rx8pilot]

I have not seriously analyzed anything, but what stands out to me is that the TPS converter circuit may not be capable of dealing with that huge capacitor on the front-end of your application circuit. There is a .03 ohm sense resistor measuring current, which probably is set up for a low output current. The inrush on the an 8200uf cap is pretty huge which would have the TPS going into fault and skipping PWM pulses to protect itself.