A current-controlled oscillator with temperature, voltage, and process compensation

This paper presents a current-controlled oscillator (CCO) circuit design with temperature, voltage, and process compensation. A current reference biasing circuit comprising a complementary-to-absolute-temperature current and a proportional-to-absolute-temperature current is used for maintaining stability during temperature variations. In addition, an output current adjustment circuit is used to overcome process variation, and the voltage variation is compensated for by the connecting structure between the current reference and oscillator. The CCO was fabricated in a 0.18-μm CMOS process. The measured temperature variation coefficient is 48.8 ppm/°C across a temperature range of 0–100 °C, and the voltage variation coefficient is 0.13% for a supply voltage ranging from 1.62 to 1.98 V; overall power consumption is 64 μW.