Self-adaptive wide voltage input circuit

Abstract

The invention belongs to the field of integrated circuit design, and particularly relates to a self-adaptive wide voltage input circuit. The circuit comprises a first module circuit and a second module circuit, wherein the module output end of the first module circuit is connected with the second module circuit; the first module circuit comprises a first current source, a first transistor, a fifth transistor, a sixth transistor, a seventh transistor, an eighth transistor, a first resistor, a second resistor, a third resistor and a fourth resistor; the second module circuit comprises a second current source, a second transistor, a third transistor, a fourth transistor and a fifth transistor; the module output end of the first module circuit is connected with the second module circuit. The output end of a first current source is connected with the emitter of a third transistor. The base of the first transistor is connected with the base of a second transistor and the collector of the second transistor. The single-chip operational amplifier can provide a wide input voltage range, has transconductance and low drift characteristics, and meets the requirement of a single-chip operational amplifier for high integration level.

Description

technical field [0001] The invention belongs to the field of integrated circuit design, in particular to an adaptive wide-width voltage input circuit. Background technique [0002] In the field of op amps, single-supply and low-supply voltage operation is often required, but this condition reduces the usable range of voltage signals. Therefore, the rail-to-rail input and output op amp came into being, and its common-mode input range and output voltage swing became the key parameters to consider. Typically, rail-to-rail inputs are used such as figure 1 shown in the double differential pair structure. However, a major disadvantage of this configuration is that its transconductance will nearly double over the entire common-mode input range. If it is used in an op amp with a feedback loop, it may cause the output waveform to be distorted. When the transconductance of the input stage changes greatly, the phase margin of the op amp will be reduced, and the stability will be de...

AI Technical Summary

Problems solved by technology

However, a major disadvantage of this structure is that its transconductance nearly doubles across the common-mode input range

If it is used in an operational amplifier with a feedback loop, it may cause distortion of the output waveform

When the transconductance of the input stage changes greatly, it will cause the phase margin of the op amp to decrease, resulting in poor stability

Images