5V (USB) to 4-50V, 50mA isolated DC/DC converter

We need  DC-DC converter which can generate a programmable voltage (via DAC or programmable potentimeter) in the range of 4V to 50V and 50mA. AND it has to be isolated with a few volt isolation - it only need to break a ground loop. It will be powered by USB (4.5V to 5.5V).

I have looked at some of the no-opto flyback controllers (LT3001, LT3002) but is seems difficult to make those programmable because the resistor which is setting the voltage is at a "flying" potential.

Can someone give me a hint as to which way to go?


  • Vin: 4.5-5.5V (USB)
  • Vo: programmable in the range 4 to 50V
  • Io: 50mA
  • Isolation voltage: 5V

By the way - LTSpice seems to lack models of LT3001 and LT3002