Patent ID: 8441301

Claim:
A cascoded level shifter for receiving an input signal in a low voltage range and for generating an output signal in a high voltage range, said cascoded level shifter being subdivided into a first voltage section and a second voltage section, said first voltage section having a lower voltage supply than said second voltage section, and a combined voltage across said first voltage section and said second voltage section corresponding to said high voltage range, said cascoded level shifter comprising: an input node in said first voltage section configured to receive an input signal; a first cascoded device disposed in said first voltage section, said first cascoded device comprising a first driver switch connected in series with a first cascode switch at a first midpoint node; a second cascoded device disposed in said second voltage section, said second cascoded device comprising a second driver switch connected in series with a second cascode switch at a second midpoint node, said second cascode switch switching in dependence on a reference voltage of a reference node and said input signal; and reference voltage perturbation circuitry configured to cause a transient perturbation to said reference voltage in response to a transition of said input signal to cause said second cascode switch to switch, wherein said reference voltage perturbation circuitry comprises a pull-down switch arranged to selectively couple said reference node to a ground voltage in dependence upon a signal generated in said first voltage section in response to detection of a transition of said input signal.