the transistor tc2 is conductive and brings the drainof the transistor t3 to the ground the transistor tc1 is off and the transistor t2 is therefore also off in the same way as above the transistor t1 will saturate the transistor but this time it is transistor t3 which will go into saturated mode sincethe two transistors t1 and t3 are identical it follows that at equilibrium the saturation mode is set up for both transistors with the same gate source voltage the output of the voltage generation stage is easily deduced therefrom equ3 and the equation of equilibrium is written as follows equ4 where v s1 and v s3 are the source voltages respectively of the transistors t1 and t3 and v 1 v 3 are their gate voltages all with respect to ground we also have v s1 v c and v s3 v out2 output of the voltage generation stage when t3 is conductive and t2 is off whence equ5 thus for a given voltage v c the output voltage will depend only on the choice of the resistance values and on the resistor ratios v sub c 12v r sub 1 3k u03c9 r sub 2 5k u03c9 v sub 1 9v r sub 3 1k u03c9 v sub 2 4v v sub out1 7v r sub 4 3k u03c9 v sub c 3v v sub out2 6v in an application to a flash eprom memory the drain voltage of a cell being programmed will be v out2.