2.3V minimum input voltage for 3.3V LDO
If you want to know something about a device, consult the datasheet from the manufacturer.  


  The minimum VIN must meet two conditions: \$V_{IN} \geq \$ 2.3V and \$V_{IN} \geq (V_R + 3.0%) + V_{DROPOUT}\$.


So, Vin must be larger in your case, about 3.3 * 1.03 + 178 mV = 3.577 V