A Process-Based Temperature Compensated On-Chip CMOS VHF VCRO in 130-nm Si-Ge BiCMOS by Implementing an Empirical Control Equation

Abstract

This paper presents a low-power CMOS temperature and process compensated 150.9 MHz Very-high-frequency (VHF) voltage-controlled-ring-oscillator (VCRO) for on-chip integration. The design employs a CMOS temperature-sensor and novel feedback control circuitry to generate the internal control-voltage for the VCRO which ensures oscillation in the vicinity of the desired frequency despite variations in temperature. The control circuitry is the implementation of an empirical equation expressing a temperature sensor-voltage into a specific control-voltage for three different process corners using three different switches. The control-voltage calibrates against temperature variation for the specific process-corner in order to maintain the same frequency of oscillation. Simulations shows that the proposed design maintains the oscillator’s frequency within 0.39% from −10°C to 90°C. The fabricated chip implemented in 130-nm GF 8HP Si-Ge BiCMOS process, occupies an area of 0.0242-mm2 and consumes 325 $\mu \text{W}$ while operating with a 1 V supply-voltage. The performance was verified through experimental immersion of DUT (device-under-test) in a temperature-controlled water-bath in the range 22.5°C–70°C.

Keywords

• Analog CMOS circuits
• temperature compensation
• process compensation
• voltage-controlled-ring-oscillator
• circuit design
• VHF