Low Power High Gain Circular Folded Cascode Amplifier

Abstract

The invention discloses a circular folded cascode amplifier with low power consumption and high gain, which is characterized in that it is composed of a main amplifier and a conductance cancellation circuit. Under the premise of changing the equivalent transconductance of the amplifier, the gain of the amplifier is further improved; the conductance canceling circuit is composed of the first conductance canceling circuit CIRCUIT_P and the second conductance canceling circuit CIRCUIT_N, and CIRCUIT_P (CIRCUIT_N) detects the cascode tubes P8 and P9 (N12, N13) The node voltage at the source terminal generates a feedback voltage to control the negative conductance generation circuit, so that the generated negative conductance becomes a function of the conductance gds of the top PMOS: P6, P7 (bottom NMOS: N10, N11), following and offsetting the top PMOS ( The gds of the bottom NMOS), if the two sides of the PMOS and the NMOS completely cancel the conductance of the top PMOS and the bottom NMOS, the output impedance and the DC gain are infinite, and the performance of the amplifier will be significantly 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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