By pSemi 39
pSemi's Digitally Tunable Capacitor (DTC) is a variable capacitor controlled with a digital interface. The digital Serial Interface (SPI or I²C) is used to control CMOS FETs that connect and disconnect fixed High-Q MIM Capacitors to obtain difference capacitance values. The use of FET stacking to create a virtual high-voltage FET enables the high power handling of the DTC. The digital control interface is fully integrated on die; no external components for bias voltage generation or interfacing are required.