I HAVE SEPIC DESIGN BASED ON LM3478MM. MY CIRCUIT HAS BEEN DESIGNED AS PER THE TEXAS INSTRUMENTS WEB BENCH (DESIGN 3533301/5 LM3478MM).
MY REQUIREMENT IS TO GENERATE 12V, 3A OUTPUT OVER AN INPUT RANGE OF 10V - 16 VOLTS. MY PROBLEM IS THAT WHEN THE FREQUENCY ADJUST RESISTOR IS CONNECTED BETWEEN THE 7TH PIN OF LM3478 AND GROUND, THE CIRCUIT DRAWS VERY EXCESSIVE CURRENT (EVEN UPTO 1.5A, AS MY POWER SUPPLY IS RESTRICTED TO 1.5A). WHEN I REMOVE THE SAME RESISTOR THE CURRENT DRAWN IS OK, BUT THERE IS NO OUTPUT VOLTAGE.
CAN ANYBODY PLEASE HELP IN SOLVING THIS ISSUE AND GETTING THE REQUIRED OUTPUT VOLTAGE.