In a high voltage pass gate suitable for use as a block decoder in a flash memory circuit, the boosting of the block decoder's internal nodes is performed using coupling capacitors and boost transistors which are decoupled from the high capacitance pass gate node. The block decoder uses three internal block decoder nodes. Each of the three nodes is held to ground by a corresponding discharge transistor when the block is unselected. Each of the three nodes of a selected block is discharged to a normal supply voltage by a corresponding diode-connected regulation transistor when the high voltage supply is turned off after a programming operation has finished. Each of the three nodes has a separate coupling capacitor associated with it. One of the nodes is connected to the gates of the high voltage pass transistors, this node has high capacitance. The remaining two nodes have relatively small coupling capacitors. These other two nodes are capacitively coupling during opposite phases of a clock, and one of them controls a boost transistor which charges the high capacitance pass gate node. Two embodiments are presented, one having one less transistor than the other.