A novel push‐pull type charge pump based on voltage doubler for LCD drivers

Abstract A novel push‐pull voltage converter structure, using a switched capacitor type voltage doubler, is proposed. The circuit is constructed with a two‐stage push‐pull voltage doubler that has a stable operation with small output ripple. The two‐stage voltage doubler creates the output voltage 4Vdd. The high clock signal is cross‐coupled to the input of the second stage with the opposite phase to reduce two switching transistors and capacitors. Simulation results verify that even with a reduced number of transistor and capacitor, there is no circuit performance loss. Adding one capacitor and two switching transistors the circuit can be changed to eight times of Vdd maker.