Low frequency analog circuit design method and its low frequency analog circuit

Abstract

The invention relates to a design method of a low-frequency analog circuit and a low-frequency analog circuit designed by the method. Because the present invention biases part of the metal oxide semiconductor transistors in the circuit in the weak inversion region, the effects of high power efficiency and low noise can be achieved.

Description

technical field [0001] The invention relates to a design method of a low-frequency analog circuit and the low-frequency analog circuit designed by the method, and in particular to a method for operating at least one MOS transistor in the circuit in a weak inversion region and the low-frequency analog circuit. Background technique [0002] Low-frequency analog circuits generally refer to analog circuits operating below 1MHz, and are mostly used for signal amplification. For example, the post-amplifier circuit of a microphone belongs to this type of circuit. Since low-frequency analog circuits are generally made into integrated circuit chips, and the MOS transistors in the integrated circuits are designed to operate in the strong inversion region (strong inversion region), for example, the NMOS transistors are operated at V gs -V th Under the condition of >0, the circuit can operate normally, but the performance of the circuit is therefore limited. Taking an NMOS transist...

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Problems solved by technology

Therefore, if you want to design a low-frequency analog circuit chip with high signal-to-noise ratio and low power consumption at the same time, it will violate the above characteristics.

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