On-chip RC oscillator circuit

Abstract

The invention discloses an on-chip RC oscillator circuit, and belongs to the technical field of integrated circuits. The on-chip RC oscillator circuit includes a low-power-consumption temperature compensation circuit, a charge and discharge control circuit, a comparator circuit, an RS flip flop, and a buffer. A first NMOS transistor, a first PMOS transistor, a fourth PMOS transistor, a third resistor and a second NMOS transistor in the low-power-consumption temperature compensation circuit form a loop for generating a bias current with a negative temperature coefficient. A second NMOS transistor, a second PMOS tube, a third PMOS transistor, a third NMOS transistor and a second resistor form a loop that generates a positive temperature coefficient current. The two loops implement a negativefeedback connection through the second NMOS transistor, and the first capacitor and the first resistor perform the miller compensation for a negative feedback loop to improve stability. The oscillator circuit only needs four current branches, and the positive and negative temperature coefficient current structure required for temperature compensation is very simple, and the power consumption is low. The first NMOS transistor, the second NMOS transistor and the third NMOS transistor operate at a sub-threshold section, achieving a smaller bias current and consuming less power.

Description

technical field [0001] The invention relates to the technical field of integrated circuits, in particular to an on-chip RC oscillator circuit. Background technique [0002] Traditional clocks are usually generated using crystal oscillators that work stably and whose oscillation frequency is less affected by power supply, temperature, and process. However, the use of an external crystal oscillator requires two additional circuit ports, and the use of external capacitors and other devices is required, which increases the overall device cost. With the increasing integration of integrated circuits, the use of on-chip RC oscillator circuits compatible with standard CMOS processes to generate clocks is gradually used in digital-analog hybrid circuits. [0003] like figure 1 Shown is a traditional structure RC oscillator circuit, the principle of which is to pass the charging current I C and discharge current I D For capacitance C 0 To charge and discharge, the capacitor C 0 ...

AI Technical Summary

Problems solved by technology

[0004] The purpose of the present invention is to provide an on-chip RC oscillator circuit to solve the problems of complex structure and high power consumption of the existing oscillator circuit

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