Self-Biasing Dynamic Startup Circuit for Current-Biased Class-C Oscillators

Abstract

This work presents a very compact self-biasing dynamic startup circuit for class-C voltage-controlled oscillators (VCOs). Using a referenceless nonlinear inverting stage, the solution has been implemented in a 28-nm CMOS technology 14-GHz oscillator, leading to a VCO startup time better than 20 ns, at par with the fastest startup circuits in literature, with an extremely compact area of 0.003 mm 2 .

A 28-GHz–195-dB FoMA 3.72-GHz/V Class-B/C Nested-gm VCO With Coupled Tail Filtering in a 65-nm CMOS

“…Another useful technique is gm boosting, which can be achieved in two ways: (1) the current paths can be arranged at the gates of two cross-coupled MOSFETs [27], [28], [29], [30], [31], [32], [33], [41], [42] or (2) the current paths can be arranged in parallel with two other MOSFETs [8], [9], [36], [43]. These methods increase the oscillation amplitude of the output signal and support rapid start-up.…”