Forum Post: RE: Power Supply Design

i designed DC DC Converter using TPS40210 and i an getting output.

but the o/p is not stable, when i decreases the Isense resistor value its voltage level increases and 

i/p current also decreases.three observations are as followes

1. Iin less then 100mA, Vin =5V, Vout=270V

2. Iin=300mA, Vin is same . Vout=35V ( when first decreases Isense resistor value then increases it stable at this value only)

please help me to make this stable for 270V at Iin=1A.

i will bw very thankful to you

Thankyou and regards 

Yogeshwar Nath