Publication . Pereira, Paula; Pinto, Antonio C.; Oliveira, Luis B.; Fernandes, Jorge R.
We present a generic model for Multiple Phase Ring
Oscillators (MPRO) with 2n phases, and derive equations for
frequency, phase and phase error under the simplifying approach
of injecting the error in a single element. Extensive Monte Carlo
simulations, at transistor level, for the four and eight phase
circuits, are in accordance with these assumptions.
These results are validated by two prototype integrated circuits,
implemented in a 130 nm CMOS technology: The first prototype,
which is a standalone four phases Ring Oscillator (RO), validates
the theoretical analysis concerning the non-linear model main
conclusions and, the second prototype, which is an eight phase RO,
incorporated as a block of an ISM receiver, validates the generic
model for CRO concept.
