Oscillator with function of temperature compensation

Abstract

The invention relates to a method for realizing temperature compensation of an oscillator and an oscillator. In the oscillator, a charging current or a discharging current is used for charging or discharging a capacitor between an upper limit of voltage and a lower limit of voltage. The method for realizing the temperature compensation of the oscillator, disclosed by the invention, comprises the following steps of: utilizing the charging current IR and the discharging current IL with the same order of temperature coefficient KI; utilizing the upper limit of voltage VUPPER, wherein the temperature characteristic of the upper limit of voltage VUPPER depends on the temperature coefficient KI of the current and the first order of temperature coefficient KR of the other circuit device; and utilizing the lower limit of voltage VLOWER which depends on the following equation of VOLOWER=-VUPPER0*KR / KI, wherein the VUPPER0 represents the value of the VUPPER at room temperature. The invention further provides the oscillator of applying the method. The oscillator disclosed by the invention has the advantages of simple structure, small change of temperature compensation along processes, easiness for migration, good robustness and the like.

Description

technical field [0001] The invention belongs to the field of circuit design, in particular to an oscillator with temperature compensation on an integrated circuit. Background technique [0002] In many applications, such as random memory refresh / communication system time base, temperature-related device drivers, etc., highly stable oscillators are required, for example, their output frequency must be stable relative to power supply voltage / temperature / time, etc. Usually the variation of frequency with respect to temperature exceeds 20% between -40°C and 80°C, so the design of temperature compensation becomes a key point in the design of on-chip oscillators. [0003] The design of the on-chip oscillator is generally implemented by controlling the current to charge and discharge the capacitor. When the voltage at one end of the capacitor reaches the upper limit, the control logic controls the discharge; when the voltage at one end of the capacitor reaches the lower limit, the ...

AI Technical Summary

Problems solved by technology

In order to achieve just the compensation to obtain temperature independent i c , requires precise control of FET voltage and resistance, both of which are often unfavorable to achieve with process variations

and i 2 need to account for the voltage variation across the capacitor to achieve a stable i 2 will be very difficult

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