This paper presents a low voltage on-chip oscillator which can compensate process, voltage, and temperature (PVT) variation in an all-digital manner. The relative reference modeling applies a pair of ring oscillators as relative references and estimates period of the internal ring oscillator. The period estimation is parameterized by a second-order polynomial. Accordingly, the oscillator compensates frequency variations in a frequency division fashion. A 1-20 MHz adjustable oscillator is implemented in a 90-nm CMOS technology with 0.04 mm 2 area. The fabricated chips are robust to variations of supply voltage from 0.9 to 1.1 V and temperature range from 0 °C to 75 °C. The low supply voltage and the small area make it suitable for low-cost and low-power systems.
|Number of pages||6|
|Journal||IEEE Transactions on Very Large Scale Integration (VLSI) Systems|
|State||Published - 1 Jan 2012|
- and temperature (PVT) variations
- Digitally controlled oscillator (DCO)
- frequency compensation
- low voltage