Questions on LT1170 and LT1370

Dear Sir/Madam

Good Day to you.

Actually I got a requirement to boost up a VIN: 3-3.6Vdc   to VOUT: 12Vdc  and able to deliver a 100W power to the load.meaning able to deliver 8.3A to the load.

I try the LT1370 and also the LT1170, however when I simulate in LTSPICE, the load of 1.6 ohms, the voltage drop to about 5.92 Vdc I only get 2.7A thru the 1.6 ohms resistor (looks like a loading effect to me.)

May I know any expert advise from your team and also any good chip you can introduce to me for this requirement?

Thank you

Warmest REgards

Ben Ho