Intermediate frequency reference source

Abstract

Since traditional reference voltage provided by band-gap reference source without temperature coefficient, and annular oscillator possesses negative temperature coefficient, thus the issue of large variant reference frequency is existed in traditional frequency source. The purpose of the invention is to provide temperature compensated medium frequency reference source including reference voltage source and annular oscillator. The reference voltage source having positive temperature coefficient outputs a reference voltage. The annular oscillator having negative temperature coefficient receives reference voltage, which is outputs from the reference voltage source, and generates oscillating signal.

Description

technical field [0001] The invention relates to a frequency source, in particular to an intermediate frequency reference source used in an integrated circuit. Background technique [0002] In many integrated circuits, many various circuits are generally integrated, and the frequency source is a relatively common circuit. In the past, only part of the frequency source circuit was fabricated in the integrated circuit, and components such as capacitors with large volumes were set in the form of external components. With the development and progress of integrated circuit technology and the increase in volume requirements, people have set up a frequency reference source that is all integrated inside an integrated circuit (that is, realized inside the integrated circuit) and does not require external components. [0003] Figure 1 shows a block diagram of a traditional frequency reference source implemented inside an integrated circuit. It consists of two parts, number 11 is a ba...

AI Technical Summary

Problems solved by technology

However, since the ring oscillator 12 itself generally has a negative temperature coefficient, and the deviation of the integration process of the ring oscillator itself will also cause changes in the output frequency

In the end, the traditional reference frequency source has a large change in the reference frequency of chips produced at different temperatures and in different batches.

The chip containing this kind of reference frequency source has relatively harsh environmental conditions in actual use, or the yield rate is significantly reduced

Moreover, the bandgap reference source uses parasitic PNP transistors in the CMOS process, resulting in increased area and power consumption

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