1. A Supply Pushing Reduction Technique for LC Oscillators Based on Ripple Replication and Cancellation
- Author
-
Chen, Yue, Liu, Yao Hong, Zong, Zhirui, Dijkhuis, Johan, Dolmans, Guido, Staszewski, Robert Bogdan, Babaie, Masoud, and Electronic Systems
- Subjects
Logic gates ,foreground calibration ,Transistors ,Frequency conversion ,voltage-controlled oscillator (VCO) ,LC oscillators ,ripple replication and cancellation ,Tracking loops ,Oscillators ,dc-dc converter ,digitally controlled oscillator (DCO) ,Delays ,LC oscillator ,supply pushing ,ommon-mode resonance ,Switches ,Common-mode resonance ,current-biased oscillator ,power supply rejection (PSR) - Abstract
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 current and thus its oscillating amplitude. The parasitic capacitance of the active devices and correspondingly the oscillation frequency are stabilized in turn. A calibration loop is also integrated on-chip to automatically set the optimum replication gain that minimizes the variation of the oscillation amplitude. A 4.9-5.6-GHz oscillator is realized in 40-nm CMOS and occupies 0.23 mm² while consuming 0.8-1.3 mW across the tuning range (TR). The supply pushing is improved to
- Published
- 2019