Amplitude limiting amplifier for improving temperature characteristic

Abstract

The invention discloses a high-performance amplitude limiting amplifier applied to a high-speed interface system. The high-performance amplitude limiting amplifier mainly solves the problem that in the prior art, the bandwidth and the swing amplitude of an amplifier are changed due to the fact that the electron mobility of a transistor changes along with temperature. The amplitude limiting amplifier comprises a load biasing circuit, an amplitude limiting amplifier core circuit and a tail current generating circuit, wherein the load biasing circuit is used for generating high bias voltage and improving the output swing of the amplitude limiting amplifier. The amplitude limiting amplifier is formed by four stages of cascade connection and is used for amplifying an input differential signal and improving the bandwidth of the amplitude limiting amplifier through an active inductance peaking technology. The tail current generation circuit generates constant swing current and constant bandwidth current at the same time, and automatically selects the larger one of the constant swing current and the constant bandwidth current according to the change of the temperature, so as to improve thebandwidth of the limiting amplifier and the temperature characteristic of the swing at the same time. The high-performance amplitude limiting amplifier has stable gain, swing amplitude and bandwidthunder various power supply voltages and temperatures, and can be used in a high-speed interface system.

Description

technical field [0001] The invention belongs to the technical field of microelectronic circuits, in particular to a limiting amplifier which can be used in high-speed interface systems. Background technique [0002] In a high-speed interface system, it is often necessary to linearly amplify the input signal with a small amplitude until the output signal of the amplifier is in the limiting state, so it is necessary to study and design a limiting amplifier with high bandwidth and large swing. For the bandwidth of the limiting amplifier, since the change of the load capacitance at the output end is small, it is basically in a constant state, so the change of its bandwidth mainly depends on the change of the transconductance of the differential input transistor of the amplifier, according to the transconductance calculation formula It can be seen that the transconductance of the transistor is related to the electron mobility, and the electron mobility decreases with the incre...

AI Technical Summary

Problems solved by technology

[0003] Existing limiting amplifying devices usually only focus on eliminating the influence of temperature on a single characteristic: that is, some amplifying devices only consider how to stabilize their output swing, but do not pay attention to the influence of temperature changes on bandwidth; while other amplifying devices only consider temperature changes The effect on the bandwidth ignores the effect of temperature changes on the amplifier output signal swing

This seriously affects the performance of the limiting amplifier, limiting its application in radio frequency systems and high-speed interface systems

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