Abstract: Techniques for providing transformer-based CMOS oscillators capable of operation with low voltage power supplies. In an exemplary embodiment, an LC tank is provided at the drains of a transistor pair, and the inductance of the LC tank is mutually magnetically coupled to an inductance between the gates of the transistor pair. A separate complementary transistor pair is also coupled to the LC tank. A further exemplary embodiment provides an LC tank at the gates of a transistor pair, as well as for three-way coupling amongst a tank inductance, an inductance between the gates of the transistor pair, and an inductance between the gates of a complementary transistor pair.

Abstract: Techniques are disclosed for trimming a capacitance associated with a capacitor bank for use in a voltage-controlled oscillator (VCO). In an embodiment, each capacitance is sub-divided into a plurality of constituent capacitances. The constituent capacitances may be selectively enabled or disabled to trim the step sizes of the capacitor bank. Further techniques are disclosed for calibrating the trimmable capacitance to minimize step size error for the capacitor bank.

Abstract: Techniques for compensating for the effects of temperature change on voltage controlled oscillator (VCO) frequency are disclosed. In an embodiment, an auxiliary varactor is coupled to an LC tank of the VCO. The auxiliary varactor has a capacitance controlled by a temperature-dependant control voltage to minimize the overall change in VCO frequency with temperature. Techniques for generating the control voltage using digital and analog means are further disclosed.