Low-power high-gain circulation type folding type cascade amplifier

Abstract

The invention discloses a low-power high-gain circulation type folding type cascade amplifier. The cascade amplifier is characterized in that the amplifier is formed by a main amplifier and an electric conductance offsetting circuit. In the main amplifier, an N44 and an N45 are crossly coupled, so equivalent transconductance of the amplifier is increased while the total current is unaltered, thereby increasing the gain of the amplifier. The electric conductance offsetting circuit is formed by a first electric conductance offsetting circuit CIRCUIT_P and a second electric conductance offsetting circuit CIRCUIT_N. The electric conductance offsetting circuit CIRCUIT_P or CIRCUIT_N detects the node voltage of source ends of cascade pipes P8, P9 (N12, N13) and generates feedback voltage to control a negative conductance generating circuit so as to allow the generated negative conductance to be functions of a top PMOS: P6, P7 (bottom NMOS: N10, N11) electric conductance so as to follow and offset gds of the top PMOS or the bottom NMOS. If two sides of the PMOS and the NMOS completely offset the electric conductance of the top PMOS and the bottom NMOS, the output resistance and zero-frequency gain are infinite, so performance of the amplifier can be remarkably improved.

Description

technical field [0001] The invention relates to a cascode amplifier, in particular to a low power consumption and high gain loop-type folded cascode amplifier, belonging to the technical field of electricity. Background technique [0002] One of the main circuit structures of analog integrated circuits is the operational transconductance amplifier, which is the module that consumes the most power in many applications. Due to the low-voltage trend of CMOS technology, folded op amps have recently become more figure 1 ) has received more attention, although the power consumption of the folding op amp is higher. Moreover, the PMOS-driven folded op amp has become the best choice for op amp applications due to its lower flicker noise, higher secondary point, and lower input common-mode level. However, PMOS-driven folding op amps also increase input capacitance and power dissipation. [0003] In addition, with the continuous reduction of the CMOS process size, in the deep sub-mi...

AI Technical Summary

Problems solved by technology

[0005] 1. Multi-stage cascaded amplifier: due to the use of complex compensation methods, the frequency response of the amplifier is seriously reduced;

[0006] 2. Transconductance doubling technology: due to the introduction of a low-gain, high-bandwidth preventive stage, the power consumption is doubled;

exist figure 1 In the circuit shown, we noticed that the two transistors N1 and N2 conduct the most current, so they have the largest transconductance, but these two transistors are only used as current sinks

Previous work to improve the performance of folded op amps has used a variety of designs, but the two transistors N1 and N2 have never been better utilized

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