Abstract: A stable super-regenerative oscillator (SRO) for industrial scientific and medical wireless receivers has been implemented in standard 0.5μm CMOS technology.The startup time of the SRO is locked by a loop composed of a voltage-controlled SRO,an efficient envelope detector,and an accurate charge pump,which is similar to a phase-locked loop without input clock.This paper presents a discrete model with stability analysis and the key circuits of the loop.Under a 2.4~5.5V supply,the measured results indicate that the startup time of the SRO is independent of changes in technology,temperature,operating frequency,and supply voltage.

Key words: super-regenerative oscillator, startup time of oscillator, phase-locked loop, wireless receiver