An Ultra Low Power Pseudoresistive Ring Oscillator for MICS Band Applications

The paper presents the design of a 2-stage MICS band differential ring oscillator. Instead of using a pseudodifferential approach, we have proposed the use of a pseudoresistor at the source coupled point. This consumes minimum headroom and contributes minimal 1/f noise. It gives good I-Q matching over voltage variations. A novel tuning circuitry is also presented. The oscillator draws a current of 300μA while operating at 400 MHz. The supply voltage used is as low as 1V for 180nm model parameters.