mosfet low vgs
LTC1693 is a simple chip that i have used before, however, the supply voltage was 5V. The spec. is somewhere around 4.5V for minimum. I think if the UVLO is below 3.3V, u can still use it, with lower drive. Have to check the datasheet for Linear Technology's website. The only reason for having UVLO is because too low a voltage may not fully enhance the FET, as the thresholds were high. However, with the new generation of low threshold FETs, new drivers should comfortably enhance it with 3V and above.
Sorry for not being able to give u a part no..