Supply-Insensitive Frequency Synthesis for an LDO-Free Powering Scheme in SoCs

The scaling of CMOS technology in deep submicron process nodes is accompanied by the integration of more and more functional blocks of a system, whether digital or analog/RF, onto the same chip (i.e., system-onchip, SoC). These blocks would also place different requirements on their power supplies. To provide various static or dynamically...

A Switched-Capacitor DC-DC Converter Powering an LC Oscillator to Achieve 85% System Peak Power Efficiency and -65 dBc Spurious Tones

In this paper, we propose a new scheme to directly power a 4.9-5.6GHz LC oscillator from a recursive switched-capacitor DC-DC converter. A finite-state machine is integrated to automatically adjust the conversion ratio and switching frequency of the converter such that its DC output voltage is within ±5% of the desired 1V across input voltage...

Analysis and Design of Power Supply Circuits for RF Oscillators

This article presents guidelines for designing the power supply blocks of RF oscillators. To preserve their spectral purity, the requirements on the noise and ripple of the supply voltage are firstly evaluated based on the oscillator supply pushing factor and the oscillator Figure-of-Merit (FOM). Those specifications are then employed to design...

A Supply Pushing Reduction Technique for LC Oscillators Based on Ripple Replication and Cancellation

In this paper, we propose a method to suppress supply pushing of an LC oscillator such that it may directly operate from a switched-mode dc-dc converter generating fairly large ripples. A ripple replication block (RRB) generates an amplified ripple replica at the gate terminal of the tail current source to stabilize the oscillator's tail...

A Tiny Quadrature Oscillator Using Low-Q Series LC Tanks

A new quadrature oscillator topology is proposed, which arranges four low-Q series LC tanks in a ring structure driven by inverters operating in class-D. With a very small area of 0.007 mm^2 that is comparable to conventional ring oscillators, this oscillator has 7–20 dB better phase noise FoM of 177 dB. It is widely tunable for nearly an octave...