A high-precision clock circuit with temperature compensation based on power supply regulation

Abstract

Based on 0.18 μm CMOS IC process, a high-precision clock circuit that controls power supply voltage to compensate temperature was presented，which effectively avoids the influence of temperature changes and power supply voltage fluctuations on the oscillation frequency. Compared with the other types of clock generating circuit, this structure does not require bandgap reference sources and operational amplifier. While optimizing performance, it greatly reduces the chip area and circuit complexity. Under the -40 ℃ to 85 ℃ temperature range, the output frequency is stable at 2 MHz and the clock deviation is less than 1%. When the power supply voltage fluctuates from 1.6 V to 2.0 V， the variation of clock oscillation frequency is 28 Hz at most.

Keywords

• ring oscillator
• temperature compensation
• clock self-correction