Variable-output charge-pump for piezoelectric and electrostatic tunable RF filters

Tunable RF filters are essential components for the coming generation of communication systems. Amongst these, RF filters, tuned electrostatically or by piezoelectric actuators, have shown excellent performance in terms of tuning range and insertion loss. Those filters, however, require a wide dynamic range control voltage. Generating such voltages is a challenge due to power and size limitations. In this work, we present a variableoutput high-voltage charge-pump that can generate a suitable voltage for those filters. The presented improved Dickson chargepump has been simulated with the control part implemented in 130 nm RF-CMOS. The voltage tuning is controlled by a digital input, easing the integration of the charge-pump with other system components. The charge-pump can generate voltages from 0 V to 45 V. At the highest output voltage, the circuit consumes only 26 mW.