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

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
.