Low-power-supply-voltage programmable gain amplifier

Abstract

The invention discloses a low-power-supply-voltage programmable gain amplifier. The low-power-supply-voltage programmable gain amplifier comprises a main transconductance stage circuit, a slave transconductance stage circuit and an output stage circuit. A tail current source of the programmable gain amplifier is arranged in a linear region in a bias mode, a transconductance stage and a differential input transconductance stage constitute a main-slave structure and are copied in a proportional mode, and the grid of a main transconductance stage tail current source and the grid of a differential input tube are connected with ports corresponding to slave transconductance stages in an operational amplifier respectively. Based on the main-slave structure, the low-power-supply-voltage programmable gain amplifier is simple in structure and can be realized through standard CMOS technologies; because a transistor is placed on the linear region or a sub-threshold value region in a bias mode, the working power supply voltage of each circuit is further reduced; forms of circuit structures are enriched under the low-power-supply-voltage environment, and the application range of the low-power-consumption programmable gain amplifier is enlarged. Normal work under small voltage is achieved through a simple structure, and therefore power consumption is substantially reduced, and performance can be well kept.

Description

technical field [0001] The invention relates to a low power supply voltage programmable gain amplifier, which belongs to the wireless communication technology. Background technique [0002] In a wireless communication system, due to changes in the surrounding environment or switching of the received channel, the signal strength received by the receiver will change significantly. If the receiving link gain is fixed, nonlinear distortion will easily occur when the input signal strength is high. If the amplifier is in a saturated state or a large signal is blocked, if the input signal is small, the useful signal will be easily overwhelmed by the noise, resulting in the failure of the subsequent circuit to demodulate, that is: if the gain of the receiving link does not vary with the input signal strength For any adjustment, a circuit with a large dynamic range must have excellent noise and linearity performance at the same time, which is often difficult to achieve. Therefore, i...

AI Technical Summary

Problems solved by technology

However, for analog circuit designers, since the threshold voltage of the MOS transistor will not decrease proportionally with the size of the transistor, the decreasing power supply voltage will cause the amplitude of the analog signal to decrease, making the linearity and signal-to-noise ratio of the analog circuit change. poor, resulting in a decrease in circuit performance

In order to make up for these defects, the method of increasing the current and bandwidth must be adopted, which will undoubtedly greatly increase the power consumption of the circuit under low power supply voltage, and as the power supply voltage continues to decrease, only increasing the current cannot make up for circuit defects.

In recent years, various low-voltage circuit implementation methods have emerged in the international community, such as double well technology, body drive technology, floating gate transistors, etc., but most of them are based on advanced technology and are expensive, which limits their application in circuit design.

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