Patent ID: 11791828

Abstract:
An apparatus comprises a cross-coupled differential amplifier, an inductive-capacitive (LC) tank circuit, and a low-noise voltage supply. The inductive-capacitive (LC) tank circuit is generally coupled in a feedback path of the cross-coupled differential amplifier. The LC tank circuit generally comprises (i) an inductance provided by an inductor, (ii) a first capacitance provided by a parallel coupled varactor circuit, (iii) a second capacitance provided by a parallel coupled first switched-capacitor bank, and (iv) a third capacitance provided by a parallel coupled second switched-capacitor bank. The low-noise voltage supply may be configured to provide a supply voltage of the cross-coupled differential amplifier. The parallel coupled varactor circuit comprises a pair of thick oxide varactors connected with a reverse varactor connection. The parallel coupled first switched-capacitor bank and the parallel coupled second switched-capacitor bank comprise thin oxide switches.