Team,
Honeywell is experiencing a problem with their LM3478. As they drop Vin from 4.8V to 4.7V, the part stops SW and the gate drive signal stays high (100% duty cycle). I have attached a schematic and a .ppt illustrating this behavior. Another thing to note is that they are pulsing the input voltage from 0 to Vin.
Vout = 44V
Iout < 350mA
Their voltage at Vsense (shown in slides 1 and 2) is <100mV. In the datasheet, the lower limit is specd at 125mV. I can't find what happens when you're below the lower threshold in the datasheet.
Please advise.
Thanks,
