VOLTAGE PUMP AND A LEVEL TRANSLATOR IRCUIT

摘要

A voltage pump and method of driving a node to an increased potential. A periodic input signal is fed into a precharged small capacitor to create a level shifted periodic intermediate potential at an intermediate node. The intermediate node is a supply node to a level translator circuit. The output of the level translator circuit controls the actuation of a pass transistor. When actuated the pass transistor drives a boosted potential to an output node of the voltage pump circuit. In one embodiment the level translator circuit has a delay element which maintains the deactivation of a pull down portion of the level translator circuit until a pull up portion of the level translator circuit is deactivated. A first diode clamp is used to limit the output of the level translator circuit and the boosted potential to within 1 threshold voltage (of the diode clamp) of each other. A second diode clamp is connected between the terminals of the pass transistor so that the boosted potential does not need to climb above the output potential plus a Vt of the second diode clamp. This in turn limits the gate potential of the transistor through the first diode clamp. In a further embodiment a precharge circuit precharges the first terminal of the transistor to a potential equal to the intermediate potential minus a threshold voltage of the precharge circuit.