looked at the max660... It's expensive and does not give the required output...
I'm looking for 1Amp @ 3.4V
And cost is an issue...

For testing purposes i'm using the TIP35(C), gate to source threshold 2V but i generally find that it operates as low as 1V just not in the 'fully on' setting...

If the -Vref is tied to the voltage rails by those diodes... then what is the point of having an external -VREF?