A clock circuit without crystal oscillator

Abstract

The invention relates to a clock circuit, and provides a crystal-oscillation-free clock circuit which is capable of effectively improving the temperature stability of a clock signal generated by the clock circuit and making the frequency of the clock signal generated by the clock circuit not changed along with the change of outside temperature, and has an extremely low temperature drift coefficient. The crystal-oscillation-free clock circuit is provided with a linear voltage stabilization module, a high-order temperature compensation module and an annular oscillation module, wherein the linear voltage stabilization module is externally connected with power supply voltage; the two same output voltage output end of the linear voltage stabilization module are connected with the input end of the high-order temperature compensation module and the input end of the annular oscillation module respectively; the reference output voltage of the linear voltage stabilization module is connected with the input end of the high-order temperature compensation module; the output end of the high-order temperature compensation module is connected with the input end of the annular oscillation module; and the annular oscillation module outputs a final clock signal.

Description

Technical field [0001] The present invention relates to a clock circuit, in particular to a high-precision low-temperature drift clock generating circuit that can be monolithically integrated without a crystal oscillator. Background technique [0002] In a digital system, the quality of the clock source directly determines the stability of the system's performance. Usually digital systems use an off-chip quartz crystal oscillator to obtain the clock source signal. The quartz crystal oscillator has superior voltage and temperature characteristics and can work stably, but it is difficult to integrate into the chip, which increases the cost of the device and hinders the high integration of the chip 化. Using standard CMOS technology to realize the on-chip clock oscillator to replace the off-chip crystal oscillator will be very helpful for reducing the cost of the system and improving the integration of the system. [0003] In the standard CMOS process, the main problem facing the real...

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Problems solved by technology

[0007] However, the compensation ideas mentioned in the above documents are based on the first-order linear relationship between the forward conduction voltage of the PN junction and the temperature to compensate for the influence of temperature, and the compensation effect is limited.

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